Skip to main content
Advertisement
Browse Subject Areas
?

Click through the PLOS taxonomy to find articles in your field.

For more information about PLOS Subject Areas, click here.

  • Loading metrics

Multidrug-resistant and extended-spectrum beta-lactamase-producing Enterobacteriaceae isolated from chicken droppings in poultry farms at Gondar City, Northwest Ethiopia

  • Mitkie Tigabie ,

    Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Project administration, Resources, Software, Writing – original draft, Writing – review & editing

    mitku1621@gmail.com

    Affiliation Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia

  • Sirak Biset,

    Roles Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing

    Affiliation Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia

  • Teshome Belachew,

    Roles Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing

    Affiliation Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia

  • Azanaw Amare,

    Roles Data curation, Formal analysis, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing

    Affiliation Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia

  • Feleke Moges

    Roles Conceptualization, Formal analysis, Methodology, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing

    Affiliation Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia

Abstract

Background

The poultry sector is one of the largest and fastest-growing agricultural sub-sector, especially in developing countries like Ethiopia. In poultry production, poultry farmers use sub-optimum doses of antibiotics for growth promotion and disease prevention purpose. This indiscriminate use of antibiotics in poultry farms contributes to the emergence of antibiotic-resistant bacteria, which has adverse implications for public health. Therefore, this study is aimed to assess multidrug resistance and extended-spectrum beta-lactamase-producing Enterobacteriaceae from chicken droppings in poultry farms.

Methods

A total of 87 pooled chicken-dropping samples were collected from poultry farms from March to June 2022. Samples were transported with buffered peptone water. Selenite F broth was used for the enrichment and isolation of Salmonella spp. Isolates were cultured and identified by using MacConkey agar, Xylose lysine deoxycholate agar, and routine biochemical tests. Kirby-Bauer disk diffusion technique and combination disk test were used for antibiotic susceptibility testing and confirmation of extended-spectrum beta-lactamase production, respectively. Data were entered using Epi-data version 4.6 and then exported to SPSS version 26 for analysis.

Result

Out of 87 pooled chicken droppings, 143 Enterobacteriaceae isolates were identified. Of these, E. coli accounts for 87 (60.8%), followed by Salmonella spp. 23 (16.1%), P. mirabilis 18 (12.6%) and K. pneumoniae 11 (7.7%). A high resistance rate was observed for ampicillin 131 (91.6%), followed by tetracycline 130 (90.9), and trimethoprim-sulfamethoxazole 94 (65.7%). The overall multidrug resistance rate was 116/143 (81.1%; 95% CI: 74.7–87.5). A total of 12/143 (8.4%; CI: 3.9–12.9) isolates were extended-spectrum beta-lactamase producers, with 11/87 (12.6%) E. coli and 1/11 (9.1%) K. pneumoniae.

Conclusion and recommendations

High prevalence of multi-drug resistant isolates was observed. This study alarms poultry as a potential reservoir of extended-spectrum beta-lactamase-producing Enterobacteriaceae, which might shed and contaminate the environment through faecal matter. Prudent use of antibiotics should be implemented to manage antibiotic resistance in poultry production.

Introduction

Poultry is one of the most widespread food animals and chicken is the largest farmed animal species worldwide [1]. The poultry sector is one of the largest and fastest-growing agricultural sub-sector, especially in developing countries like Ethiopia. It is an essential component of the country’s economy, providing income for farmers and a good source of high-quality protein for the ever-growing population of Ethiopia [2]. However, in the poultry sector, in addition to using antibiotics for therapy and disease prevention, antibiotics are regularly added to poultry feed in sub-therapeutic doses for growth promotion [3].

Globally, over 50% of antibiotics are used by the food animal industry and an increase of 50% in antibiotic usage for farming is estimated by 2030 [4]. An estimated 25 million pounds of antimicrobials are used for non-therapeutic purposes in chickens, pigs, and cows, while only 3 million pounds are used for human medicine worldwide [5].

Developed countries have implemented prudent antibiotic use policies and surveillance systems both in clinical and veterinary settings. There are no such systems in low and middle-income countries [3]. In these countries, antibiotics are used in poultry for three main reasons: 1) Poultry flock treatment when illness is first recognized in a small proportion of the chickens; 2) to prevent diseases when the physical stress involved in the movement of chickens in large numbers; and 3) as a growth promoter to boost chickens weight [6, 7].

The irrational use of antibiotics in poultry farms for growth promotion and disease prevention triggers high selection pressure among bacterial agents, which might contribute to the emergence and development of antibiotic-resistant (ABR) bacteria [8]. Antibiotic resistance increases time-to-time. It has been declared by World Health Organization as one of the top ten global public health threats in the 21st century [9]. Currently, an estimated 700,000 people a year die of ABR infections in the globe. If action is not taken, this number could rise to around 10 million per year, with a global loss of 100 trillion United States dollars by 2050 [10]. More than 2.8 million ABR occur, resulting in more than 35,000 deaths annually in the United States alone [11]. In Africa, approximately 4.2 million deaths also occur annually due to ABR [10].

Extended-spectrum beta-lactamase (ESBL) genes have led to the emergence of bacteria that are resistant to most antibiotics [12]. Extended-spectrum beta-lactamase is an enzyme that can hydrolyze penicillin, cephalosporins, and aztreonam and is inhibited by beta-lactamase inhibitors, like clavulanic acid [13]. The most common ESBL types found in poultry and poultry products are CTX-M-1, TEM-52 and SHV-12. Extended-spectrum beta-lactamase-producing bacteria are also, present in every type of commercial chicken and can be detected even in newly hatched chickens. This enzyme is most common in gram-negative bacteria, particularly in Enterobacteriaceae such as Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) [12]. Some of these bacteria are significant causes of foodborne, urinary tract, respiratory tract, bloodstream, and wound infections in humans [14].

Extended-spectrum beta-lactamase-producing bacteria in the poultry sector are recognized as a potential community health concern. Because, it can be transmitted through food chains, in close contact with poultry, leafy vegetables and via bodies of water contaminated with poultry droppings. So, it is very important to monitor the resistance to antibiotics not only in human bacterial pathogens but also in pathogenic and commensal bacteria of poultry origin [1517].

Awareness of the prevalence of ABR in poultry provides baseline data to implement an integrated ABR surveillance system and also facilitates the evaluation of interventions used to control the ABR. Monitoring and surveillance of ABR at poultry farms may help to reduce the transfer of ABR bacteria from poultry to humans directly or indirectly through the environment [18]. In Ethiopia, Multidrug resistance has not been well-studied and extended-spectrum beta-lactamase-producing Enterobacteriaceae from poultry droppings are still missing, particularly in Northwest Ethiopia. Therefore, this study is aimed to determine the multidrug resistance (MDR) and ESBL-producing Enterobacteriaceae from chicken droppings in poultry farms at Gondar City, Northwest Ethiopia.

Materials and methods

Study design, period, and area

A survey was conducted from March 1, 2022, to June 30, 2022. The study was conducted in Gondar City Ethiopia. Gondar is one of the ancient historical cities in Ethiopia and is located 737 Km from Addis Ababa, the country’s capital. The city’s total population is estimated to be 395,138 [19]. According to the information obtained from Gondar city’s rural and urban agriculture centre, 87 poultry farms supply chickens and eggs to the society.

Data collection and analysis

Data related to general characteristics and antibiotic use in the poultry farms were collected by face-to-face interview technique from the chicken caregivers or owners using a semi-structured questionnaire before sample collection. All data were collected and analyzed by a trained laboratory technologist.

Sample collection, transportation, processing, and identification

A total of 87 chicken-dropping samples were randomly collected from poultry farms. A sample consisted of a pool of five fresh chicken droppings obtained from the five different parts of the poultry building [20].

Each farm was visited once, and the samples were collected using sterile applicator sticks and stored in sterile universal sampling bottles containing 90 ml buffer peptone water (BPW) (Himedia, India M614). A code was attributed to each universal sampling bottle and placed in a cooler (icebox) containing ice packs. Immediately, samples were transported to the School of Biomedical and Laboratory Sciences, Medical Microbiology laboratory section.

After homogenization, about 1 millilitre of the sample was further transferred into two different test tubes containing 9 ml of BPW (Himedia, India, M614) and 5 ml of selenite F broth (Himedia, India M414). Test tubes were incubated at 37°C for 18–24 hrs. After incubation, samples from BPW were streaked on a MacConkey agar plate (Oxoid Ltd, Basingstoke, United Kingdom (UK)). Samples from selenite F broth were streaked on a xylose lysine deoxycholate agar plate (XLD) (HiMedia, India, M608) [21]. All the plates were incubated aerobically at 37°C for 24 hrs.

At the end of incubation, the MacConkey and XLD agar plates were examined for growth and preliminary identification of the bacteria was done based on the characteristics of the bacteria colony (size, shape, colour, texture, elevation, edge). In addition, the smear was prepared from each colony observed on the plates and gram staining was performed. The gram reaction and the shape of the bacteria were observed using a microscope.

After the identification of gram-negative bacteria, a series of biochemical tests were performed on colonies from pure cultures of the isolates. Triple sugar iron agar (TSI) (Oxoid Ltd, Basingstoke UK), Simon’s citrate agar (Oxoid Ltd, Basingstoke, UK), urease agar (Oxoid Ltd, Basingstoke, UK), lysine iron agar (Oxoid Ltd, Basingstoke, UK) (LDC), and Sulphur indole motility medium (SIM) (Oxoid Ltd, Basingstoke, UK) were included in the biochemical tests for species identification [22].

Antibiotic susceptibility testing

Following bacterial identification, the antibiotic susceptibility testing (AST) of the isolates was performed by a Kirby-Bauer disk diffusion technique. The colonies of a young culture were picked from the pure culture using a sterile wire loop and emulsified in 0.85% of normal saline to make bacterial suspension and compare with 0.5 McFarland turbidity standards. Then the bacterial suspension was inoculated onto Muller-Hinton agar (MHA) (Oxoid, Basingstoke, and Hampshire, UK) by lawn culture method. The AST was performed following the recommendation of the Clinical and Laboratory Standards Institute (CLSI) guideline 2021 against—ampicillin (10μ), gentamicin (10μg), tetracycline (30μg), nalidixic-acid [30] ciprofloxacin (5μg), chloramphenicol (30μg), trimethoprim-sulfamethoxazole (1.25μg/23.75μg), cefoxitin (30μg), cefotaxime (30μg), ceftazidime (30μg), ceftriaxone (30μg), and meropenem (10μg). All the antibiotic disks used were from BD, BBLTM Company, and USA Product. After overnight incubation at 37°C for 16–18 hours, the zone of inhibition was measured by a ruler and the results was interpreted as resistant, intermediate, and sensitive [23]. Bacterial isolates that were resistant to at least one antibiotic agent in three or more antibiotic classes were considered MDR isolates [24].

Detection of extended-spectrum beta-lactamase

All Enterobacteriaceae strains were tested against ceftriaxone, cefotaxime, and ceftazidime for ESBL screening using the Kirby-Bauer disk diffusion method. If the zone of inhibition was ≤ 22 mm for ceftazidime, ≤ 25 mm for ceftriaxone, and ≤ 27 for cefotaxime, they were considered as potential ESBLs-producing strains and selected for a further phenotypic confirmatory test as described below [23].

A phenotypic confirmatory test was done using a combined-disk diffusion test and interpreted by following the CLSI, 2021 guidelines. Pure culture of suspected ESBL producer isolates was emulsified in 0.85% saline and compared with 0.5 McFarland turbidity standard then inoculated on MHA by lawn culture method using sterile swabs. The following antibiotic disks such as cefotaxime (30μg), cefotaxime/clavulanic acid (30μg/10μg), ceftazidime (30μg), and ceftazidime/clavulanic acid (30μg/10μg) were used to confirm the status of the ESBL phenotypes. The plates were then incubated aerobically at 37°C for 16–18 hrs. If greater or equal to 5mm an increase in zone diameter for cefotaxime and ceftazidime in combination with clavulanic acid than the zone diameter of the tested alone, it was confirmed as ESBL-producing isolates [23].

Quality control

All culture media was prepared according to the manufacturer’s instructions and following standard operational procedures. The sterility of newly prepared culture media was checked by incubating 5% of prepared culture media at 35–37°C overnight before use and was evaluated for possible growth or contamination. The performance testing was performed with inoculating known control strains of E. coli American Type Culture Collection (ATCC) 25922 and Salmonella Typhimurium ATCC 14028 on culture media. For the ESBL confirmatory test, K. pneumoniae ATCC 700603 (ESBLs positive) and E. coli ATCC 25922 (ESBLs negative control) strains were used to check the quality of the culture media and antibiotic disks [23].

Data processing and analysis

All data were checked for completeness, coded, and entered using Epi-data version 4.6 and the data was exported to Statistical Package for Social Sciences version 26 for further analysis. Frequency analysis was carried out to determine the frequency of independent variables and the prevalence of MDR isolates. Fisher’s exact test was used to observe an appropriate association between independent variables and ESBL-producing isolates. A p-value of less than 0.05 at a 95% confidence interval in fisher’s exact test was considered an association between independent variables and ESBL-producing isolates. The results were presented in texts, figures, and tables.

Ethical approval

Ethical clearance was obtained from the Ethical Review Committee of the School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, the University of Gondar with protocol reference number SBMLS/202, dated 14 February 2022. The owner of each poultry farm was informed about the aim of the study and oral permission was obtained from the owners/ managers before sampling.

Results

General characteristics of the poultry farms

A total of 87 poultry farms were visited, and a farm owner or chicken caregiver was interviewed about the farm’s characteristics and how to handle the chickens. The majority of the poultry farms raised eggs layer chickens 55 (63.2%), used deep litter chicken housing systems 82 (94.3%), and used commercially prepared feeds 80 (92%). In most farms, 78 (89.7%) were not clean from chicken droppings and remained so until a new flock was introduced. In more than half of the poultry farms, diseased chickens weren’t isolated and separated. Almost all of the farm owners or the people who looked after the chickens had no profession related to the poultry industry (Table 1).

thumbnail
Table 1. General characteristics of the poultry farms at Gondar City, Northwest Ethiopia, March to June 2022.

https://doi.org/10.1371/journal.pone.0287043.t001

Antibiotic use in the poultry farms

Of most poultry farmers 82 (94.3%) used antibiotics on their farms. Antibiotics given in poultry farms were enrofloxacin, oxytetracycline, ciprofloxacin, trimethoprim and sulphadiazine. The majority of poultry farms 75/82 (91.5%) used antibiotics for both preventive and treatment purposes. Out of antibiotic users, most of the poultry farmers purchased their antibiotics from a veterinary pharmacy and gave them to their chickens by mixing them with feed or water (Table 2).

thumbnail
Table 2. Type of antibiotics use in the poultry farms at Gondar City, Northwest Ethiopia, March to June 2022.

https://doi.org/10.1371/journal.pone.0287043.t002

Prevalence of Enterobacteriaceae isolates from chicken droppings

Among a total of 87 poultry farms chicken-dropping samples 143 bacterial isolates were recovered. Of these, the most common isolates were E. coli 87 (60.8%), followed by Salmonella spp. 23 (16.1%), P. mirabilis 18 (12.6%) and K. pneumoniae 11 (7.7%). E. coli 87 (100%) was recovered from all samples collected. However, Salmonella spp. were isolated in 23 (26.4%; 95% CI:17.2–35.6) and P. mirabilis in 18 (20.7%; 95% CI:12.6–28.7) samples (Fig 1).

thumbnail
Fig 1. The proportion of Enterobacteriaceae isolates from chicken droppings in poultry farms at Gondar City, Northwest Ethiopia, March to June 2022.

https://doi.org/10.1371/journal.pone.0287043.g001

Antibiotic resistance patterns of Enterobacteriaceae

Out of 143 Enterobacteriaceae isolates, the highest resistance rate was observed for ampicillin 131 (91.6%) followed by tetracycline 130 (90.9), trimethoprim-sulfamethoxazole 94 (65.7%), and nalidixic acid 94 (65.7) and lowest resistance was observed against meropenem 13 (9.1%), gentamicin 16 (11.2%) and cefoxitin 24 (16.8%) (Table 3).

thumbnail
Table 3. Antibiotic resistance patterns of Enterobacteriaceae from chicken droppings in poultry farms at Gondar city, Northwest Ethiopia, March to June 2022.

https://doi.org/10.1371/journal.pone.0287043.t003

Regarding the resistance rate of individual bacterial isolates, E. coli demonstrated a high rate of resistance against ampicillin 80/87 (92.0%), tetracycline 79/87 (90.8%), nalidixic acid 59/87 (67%), and trimethoprim-sulfamethoxazole 55/87 (63.2%). Likewise, K. pneumoniae isolates showed a high resistance rate against ampicillin 11/11 (100%), tetracycline 10/11 (90.9%), trimethoprim-sulfamethoxazole 9/11 (81.8%), and nalidixic acid 7/11 (63.6%). All isolates showed a lower resistance rate against meropenem and gentamicin, with a range of 9.2% to 18.2% and 4.3% to 25.0%, respectively.

Multi-drug resistant patterns of Enterobacteriaceae

A total of 12 antibiotics from 8 classes (aminoglycosides, amphenicol, carbapenems, cephalosporins, fluoroquinolones, folate pathway inhibitors, penicillin, and tetracycline) were used to assess the MDR patterns of isolates. The overall MDR prevalence in this study was 116/143 (81.1%; 95% CI: 74.7–87.5). The most common MDR isolates identified in this study were E. coli 73/87 (83.9%; 95% CI: 76.3–91.5) followed by K. pneumoniae 9/11 (81.8%; 95% CI: 69.1–94.5), P. mirabilis 14/18 (77.8%; 95% CI: 58.8–96.8), and Salmonella spp. 17/23 (73.9%; 95% CI: 55.9–91.9) (Table 4).

thumbnail
Table 4. Multidrug resistance profiles of Enterobacteriaceae isolates from chicken droppings in poultry farms at Gondar city, Northwest Ethiopia, March to June 2022.

https://doi.org/10.1371/journal.pone.0287043.t004

The prevalence of ESBL-producing Enterobacteriaceae

Among 143 bacterial isolates tested for ESBL, 12 (8.4%; CI: 3.9-12-9) were found to be positive. Of these, 11/87 (12.6%; 95% CI: 5.5–20.1) were E. coli and only one of the isolates was 1/11(9.1%; 95% CI: 1.5–27.3) K. pneumoniae.

Discussion

Antibiotic-resistant bacteria are a significant public health concern because the resistant bacteria and their mobile genetic elements disseminate among animals, humans, and the environment [25].

In this study, a total of 87 pooled chicken droppings were collected for bacteriological analysis and all of them were culture-positive. The culture-positivity rate in this study is in agreement with reports from Tanzania (100%) [26] and Indonesia (100%) [27]. However, it is higher than a study conducted in Jimma, Ethiopia 43.6% [28], Tanzania 55.2% [29], Egypt 12.5% and 25.6% [30, 31] Cameroon 44.1% [32], Nigeria 29.5% [33] and Albania 52.9% [34]. The difference in culture positivity rate may be due to the methods used to isolate the bacteria, the types of samples, and hygienic conditions in different places. In this study, for example, different types of samples were pooled, and most farms did not clean chicken droppings until a new flock was introduced, resulting in them being mixed with chicken feed, which fosters the cross-contamination of chickens [35].

In the current study, 143 Enterobacteriaceae isolates were identified, and the most predominant isolate was E. coli 87 (60.8%), followed by Salmonella spp. 23 (16.1%) and P. mirabilis 18 (12.6%). The same finding was also reported from Jimma, Ethiopia [28], Kenya [21], Nigeria [36], Côte d’Ivoire [20], and Malaysia [37]. The predominance of E. coli in this and many other studies may be because E. coli is a ubiquitous commensal bacterium that is predominantly found in the gastrointestinal tracts of animals and humans as a normal flora [38].

This study revealed that isolates from chicken droppings showed high resistance against ampicillin, tetracycline, and trimethoprim-sulfamethoxazole. This was also reported from Jimma, Ethiopia [28], Hawassa, Ethiopia [39], Tanzania [26, 29], Zambia [40], Cameroon [32], Côte d’Ivoire [20], Bangladesh [41], and Indonesia [42]. This demonstrates that these antibiotics are relatively cheap, easily accessible, and widely used antibiotics in the countries [43]. During farming, antibiotics are used for treatment or preventive purposes that favours the spread of ABR Enterobacteriaceae which can infect humans through the food chain [44]. In this study, these antibiotics were used in poultry for treatment or preventive purposes.

Moreover, the current study recorded higher resistance to quinolones like nalidixic acid 94 (65.7%) and ciprofloxacin 38 (26.6%). The use of quinolones for therapeutic purposes on the farm may be a possible contribution. The resistant pattern of Enterobacteriaceae in poultry to clinically important antibiotics in humans that are used for treating infections is a great concern [45]. For instance, in this study, enrofloxacin and ciprofloxacin are the most used antibiotics in poultry farms.

Bacterial isolates in the present study showed a relatively lower rate of resistance against meropenem 13 (9.1%) and gentamicin 16 (11.2%). This finding is supported by other studies, in Hawassa, Ethiopia [39], Kenya [21], and Albania [34]. Those studies reported 0% to 15% resistance for gentamicin and meropenem. Also, in Tanzania, gentamicin 10.3%, and 10.8% [26, 29], However, our result is lower than the studies conducted in Zambia, gentamicin 37.7% [40], Cameroon, meropenem 45% [32], Côte d’Ivoire, gentamicin 47.2% [20], Bangladesh, gentamicin 53% [41], and Indonesia, gentamicin 37% [27]. The possible explanation for a lower rate of resistance could be because of the inaccessibility of antibiotic agents that may not be given to poultry in the study area.

The prevalence of MDR E. coli in this study was 73 (83.9%). This finding is consistent with reports from Tanzania 86.8% [26], Zambia 85.7% [40], and Cameroon 83.1% [32] and lower than the study in Albania 95% [34], and in Malaysia 100% [37]. However, it is higher than a study conducted in Jimma, Ethiopia 54.2% [28], Tanzania 69.3% [29], and Egypt 57.8% [30]. This bacteria strain might be human pathogenic E. coli since, similar virulence factors with the same mechanism between avian pathogenic E. coli and human extra-intestinal pathogenic E. coli strains [46], and genetic similarity between E. coli involved in urinary tract infections in humans and those found in poultry and poultry products has been demonstrated [47].

The multidrug resistance rate of Salmonella spp. was 17 (73.9%). This is in agreement with a report from Debre Zeit, Ethiopia 86.0% [48], Albania 82% [34], and Malaysia 82% [37]. However, it is higher than a study conducted in Jimma, Ethiopia 44.4% [28]. This discrepancy could be due to the inappropriate use of antibiotics on the farms represents a selective pressure for resistant bacteria which can develop cross-resistance between several classes of antibiotics [49].

The prevalence of MDR K. pneumoniae, P. mirabilis, and E. cloacae in this study was 81.8%, 77.8%, and 75%, respectively. This is in line with the study conducted in Bangladesh P. mirabilis 83% [41]. However, these findings are higher than a study conducted in Jimma, Ethiopia, where 57.1% of K. pneumoniae and 50.0% of P. mirabilis reported as MDR [28], and 53.57% of K. pneumoniae was also reported as MDR by a study from Indonesia [42]. These bacteria may develop ABR via acquired mechanisms. The acquired resistance occurs through horizontal gene transfer such as conjugation, transduction, and transformation from other resistant bacteria. Additionally, mutations in the gene could also cause this MDR when the bacteria are constantly under pressure after being exposed to antibiotics [50].

The overall prevalence of MDR Enterobacteriaceae was 116 (81.1%; 95% CI: 74.7–87.5). This is higher than a report from Jimma, Ethiopia where the MDR prevalence was 52.5% [28]. This difference may be due to the types of commercial chicken, and the number of farms included in the study [51]. For instance, the present study includes multiple poultry farms and different types of commercial chickens such as layer, broiler, and day-old chickens.

In the present study, the ESBL-producing Enterobacteriaceae from chicken droppings was 8.4%, and the prevalence of ESBL-producing E. coli and K. pneumoniae was 12.6% and 9.1%, respectively. This finding is in line with the studies conducted in Uganda E. coli 17.5% [52], Egypt E. coli 12.5% [31], Tanzania E. coli 10.29% [26], India K. pneumoniae 5% [53], and Indonesia E. coli 7.03% [27], and it is lower than studies in Zambia E. coli 20.1% [40], Nigeria E. coli 37.8% [54], Ghana E. coli 29% [44]. In contrast, our result is higher than the study conducted in Tanzania E. coli 4.7% [29], India E. coli 5.3% [53], and Indonesia E. coli 3.3% [55]. This variation in prevalence rates could be the difference in ESBL screening methods used and it might be due to poor animal management practices and hygienic conditions; chicken dropping has contact with chicken feedings that enhance the spread of MDR bacteria in the flock [35].

Extended-spectrum beta-lactamase-producing E. coli and K. pneumoniae have been frequently reported in poultry and therefore poultry production might serve as a reservoir for ESBL-producing strains [56]. Different ESBL genes might exist and spread on various mobile genetic elements like plasmids that can transfer horizontally between bacterial species [57]. There is a significant association between the prevalence of ESBL and flock size (p = 0.014). The occurrence of ESBL increased with high flock size than the lower number of chickens on the farm. This finding is in agreement with the results of a study conducted in Uganda [52]. High flock size may increase stocking density which led to increased levels of airborne and respiratory disease transmission, thus increasing the risk of their environmental contamination with different bacterial strains. This is probably the cause of the reduced immune responses observed at high stocking densities, as high stocking density causes reduced feed consumption and lower growth rates. This leads to more susceptibility to ESBL-producing bacterial infection [58].

In this study, chickens aged less than two months were high risk to ESBL-producing Enterobacteriaceae carriage (p = 0.037). Because the gut normal flora of these birds is still maturing, making it easy for colonization by various pathogenic bacteria if they are exposed to the poultry environment. Additionally, due to their lower immunity, survival and multiplication of ingested ESBL-producing Enterobacteriaceae via the gastrointestinal tract is increased [59].

The occurrence of ESBL was significantly associated with the use of ciprofloxacin (p = 0.001) and trimethoprim-sulphadiazine (p = 0.018). This may be because the inappropriate use of these antibiotics in the farms represents a selective pressure for resistant bacteria which can develop cross-resistance between several classes of antibiotics like beta-lactam antibiotics [49]. In addition, these antibiotics were used for the treatment and prevent diseases in commercial farms in mass with crowded poultry flocks, these practices lead to a massive accumulation of antibiotics in the farm environment and facilitate the acquisition of resistance genes in bacteria coming in contact with them [60]. These bacteria are capable of being transmitted to humans through direct contact with infected birds and the consumption of contaminated food chains [15].

Limitations of the study

Isolation was performed on MacConkey and XLD agar which limits the isolation of fastidious Enterobacteriaceae and molecular characterization of the isolates wasn’t conducted.

Conclusions and recommendations

A high prevalence of clinically important bacterial pathogens with a high prevalence of MDR and ESBL-producing E. coli and K. pneumoniae were recovered in the present study. Poultry farms may be one potential reservoir for Enterobacteriaceae that shed into the environment through faecal matter contamination which might be a potential public health concern. Therefore, close supervision of poultry farms handling large flocks and day-old chickens should not be underestimated. The prudent use of antibiotics in poultry farms is better to be strictly supervised.

Supporting information

Acknowledgments

The authors would like to thank the Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, the University of Gondar. We also acknowledge Gondar city’s rural and urban agriculture centre and the poultry farm owners.

References

  1. 1. Agyare C, Boamah VE, Zumbi CN, Osei FB. Antibiotic use in poultry production and its effects on bacterial resistance. Antimicrobial resistance-A global threat. 2018:1–20.
  2. 2. Alemneh T, Getabalew M. Exotic chicken production performance, status and challenges in Ethiopia. Int J Vet Sci Res. 2019;5(2):039–45.
  3. 3. Schar D, Sommanustweechai A, Laxminarayan R, Tangcharoensathien V. Surveillance of antimicrobial consumption in animal production sectors of low-and middle-income countries: Optimizing use and addressing antimicrobial resistance. PLoS medicine. 2018;15(3):e1002521. pmid:29494582
  4. 4. Van Boeckel TP, Brower C, Gilbert M, Grenfell BT, Levin SA, Robinson TP, et al. Global trends in antimicrobial use in food animals. Proceedings of the National Academy of Sciences. 2015;112(18):5649–54. pmid:25792457
  5. 5. Landers TF, Cohen B, Wittum TE, Larson EL. A review of antibiotic use in food animals: perspective, policy, and potential. Public health reports. 2012;127(1):4–22. pmid:22298919
  6. 6. Besier R, Kahn L, Sargison N, Van Wyk J. Diagnosis, treatment and management of Haemonchus contortus in small ruminants. Advances in parasitology. 2016;93:181–238. pmid:27238006
  7. 7. Phillips I, Casewell M, Cox T, de Groot B, Friis C, Jones R, et al. Does the use of antibiotics in food animals pose a risk to human health? A reply to critics. Journal of Antimicrobial Chemotherapy. 2004;54(1):276–8.
  8. 8. Kousar S, Rehman N, Javed A, Hussain A, Naeem M, Masood S, et al. Intensive Poultry Farming Practices Influence Antibiotic Resistance Profiles in Pseudomonas Aeruginosa Inhabiting Nearby Soils. Infection and Drug Resistance. 2021:4511–6. pmid:34744442
  9. 9. World Health Organization. Ten threats to global health in 2019 2019 [cited 2021 December 24]. Available from: https://www.who.int/news-room/spotlight/ten-threats-to-global-health-in-2019.
  10. 10. O’Neill J. Tackling drug-resistant infections globally: final report and recommendations 2016 [cited 2022 February 16]. Available from: https://apo.org.au/sites/default/files/resource-files/2016-05/apo-nid63983.pdf.
  11. 11. Centers for Disease Control and Prevention. Antibiotic Resistance Threats in the United States 2019 [cited 2022 February 12]. Available from: https://www.cdc.gov/drugresistance/pdf/threats-report/2019-ar-threats-report-508.pdf.
  12. 12. Saliu EM, Vahjen W, Zentek J. Types and prevalence of extended-spectrum beta-lactamase producing Enterobacteriaceae in poultry. Anim Health Res Rev. 2017;18(1):46–57. pmid:28641596
  13. 13. Saravanan M, Ramachandran B, Barabadi H. The prevalence and drug resistance pattern of extended spectrum β–lactamases (ESBLs) producing Enterobacteriaceae in Africa. Microbial pathogenesis. 2018;114:180–92.
  14. 14. Xu Y, Liu Y, Liu Y, Pei J, Yao S, Cheng C. Bacteriophage therapy against Enterobacteriaceae. Virol Sin. 2015;30(1):11–8. pmid:25662887
  15. 15. World Health Organization. Salmonella (non-typhoidal) 2018 [cited 2022 September 16]. Available from: https://www.who.int/news-room/fact-sheets/detail/salmonella-(non-typhoidal).
  16. 16. Ma F, Xu S, Tang Z, Li Z, Zhang L. Use of antimicrobials in food animals and impact of transmission of antimicrobial resistance on humans. Biosafety and Health. 2021;3(01):32–8.
  17. 17. Hedman HD, Vasco KA, Zhang L. A review of antimicrobial resistance in poultry farming within low-resource settings. Animals. 2020;10(8):1264. pmid:32722312
  18. 18. Mouiche MMM, Moffo F, Akoachere JTK, Okah-Nnane NH, Mapiefou NP, Ndze VN, et al. Antimicrobial resistance from a one health perspective in Cameroon: a systematic review and meta-analysis. BMC Public Health. 2019;19(1):1135. pmid:31426792
  19. 19. World Population Review. Gondar Population 2022 2022 [cited 2022 Februay 12]. Available from: https://worldpopulationreview.com/world-cities/gondar-population.
  20. 20. Assoumy MA, Bedekelabou AP, Teko-Agbo A, Ossebi W, Akoda K, Nimbona F, et al. Antibiotic resistance of Escherichia coli and Salmonella spp. strains isolated from healthy poultry farms in the districts of Abidjan and Agnibilékrou (Côte d’Ivoire). Veterinary World. 2021;14(4):1020.
  21. 21. Langata LM, Maingi JM, Musonye HA, Kiiru J, Nyamache AK. Antimicrobial resistance genes in Salmonella and Escherichia coli isolates from chicken droppings in Nairobi, Kenya. BMC research notes. 2019;12(1):1–6.
  22. 22. Cheesbrough M. District laboratory practice in tropical countries, part 2: Cambridge university press; 2006.
  23. 23. Clinical and Laboratory Standards Institute. Performance Standards for Antimicrobial Susceptibility Testing. 31st ed. CLSI. supplement. M100 2021 [cited 2021 February 24]. Available from: https://www.treata.academy/wp-content/uploads/2021/03/CLSI-31-2021.pdf.
  24. 24. Magiorakos A-P, Srinivasan A, Carey RB, Carmeli Y, Falagas M, Giske C, et al. Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance. Clinical microbiology and infection. 2012;18(3):268–81. pmid:21793988
  25. 25. Robinson TP, Bu D, Carrique-Mas J, Fèvre EM, Gilbert M, Grace D, et al. Antibiotic resistance is the quintessential One Health issue. Transactions of the Royal Society of Tropical Medicine and Hygiene. 2016;110(7):377–80. pmid:27475987
  26. 26. Kiiti RW, Komba EV, Msoffe PL, Mshana SE, Rweyemamu M, Matee MIN. Antimicrobial Resistance Profiles of Escherichia coli Isolated from Broiler and Layer Chickens in Arusha and Mwanza, Tanzania. International Journal of Microbiology. 2021;21:9. pmid:34721584
  27. 27. Effendi MH, Tyasningsih W, Yurianti YA, Rahmahani J, Harijani N, Plumeriastuti H. Presence of multidrug resistance (MDR) and extended-spectrum beta-lactamase (ESBL) of Escherichia coli isolated from cloacal swab of broilers in several wet markets in Surabaya, Indonesia. Biodiversitas Journal of Biological Diversity. 2021;22(1).
  28. 28. Atnafu Bushen ET, Abayneh M. Drug-and Multidrug-Resistance Pattern of Enterobacteriaceae Isolated from Droppings of Healthy Chickens on a Poultry Farm in Southwest Ethiopia. Infection and drug resistance. 2021;14:2051. pmid:34103951
  29. 29. Mgaya FX, Matee MI, Muhairwa AP, Hoza AS. Occurrence of multidrug resistant Escherichia coli in raw meat and cloaca swabs in poultry processed in slaughter slabs in Dar es Salaam, Tanzania. Antibiotics. 2021;10(4):343. pmid:33804812
  30. 30. AbdelRahman MAA, Roshdy H, Samir AH, Hamed EA. Antibiotic resistance and extended-spectrum beta-lactamase in Escherichia coli isolates from imported 1-day-old chicks, ducklings, and turkey poults. Vet World. 2020;13(6):1037–44.
  31. 31. Moawad AA, Hotzel H, Neubauer H, Ehricht R, Monecke S, Tomaso H, et al. Antimicrobial resistance in Enterobacteriaceae from healthy broilers in Egypt: emergence of colistin-resistant and extended-spectrum β-lactamase-producing Escherichia coli. Gut pathogens. 2018;10(1):1–12.
  32. 32. Moffo F, Mouiche MMM, Djomgang HK, Tombe P, Wade A, Kochivi FL, et al. Poultry litter contamination by Escherichia coli resistant to critically important antimicrobials for human and animal use and risk for public health in cameroon. Antibiotics. 2021;10(4):402. pmid:33917678
  33. 33. Olonitola OS, Fahrenfeld N, Pruden A. Antibiotic resistance profiles among mesophilic aerobic bacteria in Nigerian chicken litter and associated antibiotic resistance genes. Poultry science. 2015;94(5):867–74.
  34. 34. Alcaine S, Molla L, Nugen S, Kruse H. Results of a pilot antibiotic resistance survey of Albanian poultry farms. Journal of global antimicrobial resistance. 2016;4:60–4. pmid:27436396
  35. 35. Ngai DG, Nyamache AK, Ombori O. Prevalence and antimicrobial resistance profiles of Salmonella species and Escherichia coli isolates from poultry feeds in Ruiru Sub-County, Kenya. BMC research notes. 2021;14(1):1–6.
  36. 36. Omoya F, Ajayi K. Antibiotic resistance pattern of pathogenic bacteria isolated from poultry droppings in Akure, Nigeria. Futa Journal of Research in Sciences. 2016;12(2):219–27.
  37. 37. Ibrahim S, Wei Hoong L, Lai Siong Y, Mustapha Z, CW Zalati CS, Aklilu E, et al. Prevalence of antimicrobial resistance (AMR) Salmonella spp. and Escherichia coli isolated from broilers in the East Coast of Peninsular Malaysia. Antibiotics. 2021;10(5):579. pmid:34068312
  38. 38. Torres AG, Arenas-Hernández MM, Martínez-Laguna Y. Overview of Escherichia coli. Pathogenic Escherichia coli in latin America; 2010. p. 1–7.
  39. 39. Abdi RD, Mengstie F, Beyi AF, Beyene T, Waktole H, Mammo B, et al. Determination of the sources and antimicrobial resistance patterns of Salmonella isolated from the poultry industry in Southern Ethiopia. BMC infectious diseases. 2017;17(1):1–12.
  40. 40. Chishimba K, Hang’ombe BM, Muzandu K, Mshana SE, Matee MI, Nakajima C, et al. Detection of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Market-Ready Chickens in Zambia. International Journal of Microbiology. 2016;16:52. pmid:27190518
  41. 41. Nahar A, Siddiquee M, Nahar S, Anwar KS, Islam S. Multidrug resistant-proteus mirabilis isolated from chicken droppings in commercial poultry farms: Bio-security concern and emerging public health threat in Bangladesh. Journal of Biosafety & Health Education. 2014;16(2):1–37.
  42. 42. Permatasari DA, Witaningrum AM, Wibisono FJ, Effendi MH. Detection and prevalence of multidrug-resistant Klebsiella pneumoniae strains isolated from poultry farms in Blitar, Indonesia. Biodiversitas Journal of Biological Diversity. 2020;21(10).
  43. 43. Kimera ZI, Mshana SE, Rweyemamu MM, Mboera LE, Matee MI. Antimicrobial use and resistance in food-producing animals and the environment: an African perspective. Antimicrobial Resistance & Infection Control. 2020;9(1):1–12. pmid:32122406
  44. 44. Falgenhauer L, Imirzalioglu C, Oppong K, Akenten CW, Hogan B, Krumkamp R, et al. Detection and characterization of ESBL-producing Escherichia coli from humans and poultry in Ghana. Frontiers in microbiology. 2019;9:3358. pmid:30697208
  45. 45. Nguyen VT, Carrique-Mas JJ, Ngo TH, Ho HM, Ha TT, Campbell JI, et al. Prevalence and risk factors for carriage of antimicrobial-resistant Escherichia coli on household and small-scale chicken farms in the Mekong Delta of Vietnam. Journal of Antimicrobial Chemotherapy. 2015;70(7):2144–52. pmid:25755000
  46. 46. Najafi S, Rahimi M, Nikousefat Z. Extra intestinal pathogenic Escherichia coli from human and avian origin: Detection of the most common virulence-encoding genes. Veterinary Research Forum. 2019;10(1):43–9. pmid:31183015
  47. 47. Sarowska J, Olszak T, Jama-Kmiecik A, Frej-Madrzak M, Futoma-Koloch B, Gawel A, et al. Comparative Characteristics and Pathogenic Potential of Escherichia coli Isolates Originating from Poultry Farms, Retail Meat, and Human Urinary Tract Infection. Life. 2022;12(6):845. pmid:35743876
  48. 48. Asfaw Ali D, Tadesse B, Ebabu A. Prevalence and Antibiotic Resistance Pattern of Salmonella Isolated from Caecal Contents of Exotic Chicken in Debre Zeit and Modjo, Ethiopia. International Journal of Microbiology. 2020;20:1–6. pmid:32047517
  49. 49. Chantziaras I. Epidemiology of antimicrobial resistance in commensal E. coli: focus on selection and spread of fluoroquinolone resistance in broilers. Ghent University. 2017;12(2):122.
  50. 50. Tenover FC. Mechanisms of antimicrobial resistance in bacteria. The American journal of medicine. 2006;119(6):3–10.
  51. 51. Daehre K, Projahn M, Semmler T, Roesler U, Friese A. Extended-spectrum beta-lactamase-/AmpC beta-lactamase-producing Enterobacteriaceae in broiler farms: transmission dynamics at farm level. Microbial Drug Resistance. 2018;24(4):511–8. pmid:28981392
  52. 52. Kakooza S, Munyiirwa D, Ssajjakambwe P, Kayaga E, Tayebwa DS, Ndoboli D, et al. Epidemiological Dynamics of Extended-Spectrum β-Lactamase- or AmpC β-Lactamase-Producing Escherichia coli Screened in Apparently Healthy Chickens in Uganda. Scientifica. 2021;21:32.
  53. 53. Bhardwaj K, Shenoy S, Baliga S, Unnikrishnan B, Baliga BS, Shetty VK. Research Note: Characterization of antibiotic resistant phenotypes and linked genes of Escherichia coli and Klebsiella pneumoniae from healthy broiler chickens, Karnataka, India. Poultry Science. 2021;100(6):101094. pmid:33989952
  54. 54. Aworh MK, Kwaga J, Okolocha E, Harden L, Hull D, Hendriksen RS, et al. Extended-spectrum ß-lactamase-producing Escherichia coli among humans, chickens and poultry environments in Abuja, Nigeria. One Health Outlook. 2020;2(1):1–11.
  55. 55. Wibisono FJ, Sumiarto B, Untari T, Effendi MH, Permatasari DA, Witaningrum AM. The presence of extended-spectrum beta-lactamase (ESBL) producing scherichia coli on layer chicken farms in Blitar Area, Indonesia. Biodiversitas. 2020;21(6):2667–71.
  56. 56. Mikhayel M, Leclercq SO, Sarkis DK, Doublet B. Occurrence of the Colistin resistance gene mcr-1 and additional antibiotic resistance genes in ESBL/AmpC-producing Escherichia coli from poultry in Lebanon: A nationwide survey. Microbiology Spectrum. 2021;9(2):25–1. pmid:34494875
  57. 57. Partridge SR, Kwong SM, Firth N, Jensen SO. Mobile genetic elements associated with antimicrobial resistance. Clinical microbiology reviews. 2018;31(4):88–17. pmid:30068738
  58. 58. Bilal RM, Hassan F-u, Farag MR, Nasir TA, Ragni M, Mahgoub HA, et al. Thermal stress and high stocking densities in poultry farms: Potential effects and mitigation strategies. Journal of Thermal Biology. 2021;99:102944. pmid:34420608
  59. 59. Kers JG, Velkers FC, Fischer EA, Hermes GD, Stegeman JA, Smidt H. Host and environmental factors affecting the intestinal microbiota in chickens. Frontiers in microbiology. 2018;9:235. pmid:29503637
  60. 60. Allen HK. Antibiotic resistance gene discovery in food-producing animals. Current Opinion in Microbiology. 2014;19:25–9. pmid:24994584