Fluoroquinolone-resistantEscherichia coliisolated from healthy broilers with previous exposure to fluoroquinolones: Is there a link?

One Health Approach to Tackle Microbial Contamination on Poultries-A Systematic Review

This study reports the search of available data published regarding microbial occupational exposure assessment in poultries, following the PRISMA methodology. Air collection through filtration was the most frequently used. The most commonly used passive sampling method was material collection such as dust, cages, soils, sediment, and wastewater. Regarding assays applied, the majority of studies comprised culture-based methods, but molecular tools were also frequently used. Screening for antimicrobial susceptibility was performed only for bacteria; cytotoxicity, virological and serological assays were also performed. Most of the selected studies focused on bacteria, although fungi, endotoxins, and β-glucans were also assessed. The only study concerning fungi and mycotoxins reported the carcinogenic mycotoxin AFB1. This study gives a comprehensive overview of microbial contamination in the poultry industry, emphasizing this setting as a potential reservoir of microbial pathogens threatening human, animal, and environmental health. Additionally, this research helps to provide a sampling and analysis protocol proposal to evaluate the microbiological contamination in these facilities. Few articles were found reporting fungal contamination in poultry farms worldwide. In addition, information concerning fungal resistance profile and mycotoxin contamination remain scarce. Overall, a One Health approach should be incorporated in exposure assessments and the knowledge gaps identified in this paper should be addressed in further research.

An Integrated Perspective on Virulence-Associated Genes (VAGs), Antimicrobial Resistance (AMR), and Phylogenetic Clusters of Pathogenic and Non-pathogenic Avian Escherichia coli

Avian pathogenic Escherichia coli (APEC) is an important bacterial pathogen that causes avian colibacillosis and leads to huge economic losses in the poultry industry. Different virulence traits contribute to pathogenesis of APEC infections, and antimicrobial resistance (AMR) has also been an overwhelming issue in poultry worldwide. In the present study, we aimed to investigate and compare the presence of virulence-associated genes (VAGs), AMR, and phylogenetic group's distribution among APEC and avian fecal E. coli (AFEC) strains. E. coli from birds with colisepticemia and yolk sac infection (YSI) (APEC) plus E. coli strains from the feces of healthy birds (AFEC) were compared by the aforementioned traits. In addition, the clonal relatedness was compared using Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Although all strains were susceptible to fosfomycin, ceftriaxone, and cefixime, almost all strains (98%) were multi-drug resistant (MDR). All strains (except two) harbored at least three or more VAGs, and the virulence scores tended to be higher in pathogenic strains especially in the colisepticemic group. All phylogenetic groups were found in isolates from YSI, colisepticemia, and the feces of healthy birds; however, the frequency of phylogroups varied according to the source of the isolate. B1 and C phylogroups were statistically more likely to be found among APEC from YSI and colisepticemic E. coli groups, respectively, while phylogroup A was the most frequently occurring phylogroup among AFEC strains. Our findings also revealed that AMR and VAGs are not essentially co-evolved traits as in some instances AMR strains were more prevalent among AFEC. This reflects the divergent evolutionary pathways of resistance acquisition in pathogenic or non-pathogenic avian E. coli strains. Importantly, strains related to phylogenetic group C showed higher virulence score and AMR that requires further attention. To some extent, ERIC-PCR was able to group strains by isolation source, phylogroup, or virulence genes. Further integrated studies along with assessment of more detailed genotypic and phenotypic features could potentially lead to better understanding of virulence, resistance, and evolution of ExPEC.

Risk assessment of fluoroquinolones from poultry muscle consumption: Comparing healthy adult and pre-school populations

Antibiotics, especially fluoroquinolones (FQs), have been largely used in animal husbandry namely poultry production. Therefore, this study aimed to identify, quantify and estimate the daily intake for adult and 3-year-old populations of the FQs norfloxacin (NOR), ciprofloxacin (CIP) and enrofloxacin (ENR) through poultry muscle consumption. The results showed detection frequencies of 78% and 62% in supermarket and school canteen samples, respectively. Of the 182 analysed samples, 4 did not comply with ENR maximum residue level (MRL), and 9 were contaminated with NOR, not allowed as a veterinary medicine of food-producing animals. The highest estimated daily intake value was obtained for the 3-year-old population regarding the sum of ENR and CIP (0.46 μg kg^-1 day^-1); value substantially lower than the established acceptable daily intake (2.0 μg kg^-1 day^-1). Although the low risk found, the high detection frequencies support the apprehension of the different international organizations, towards the emergence of human bacterial resistances to FQs originated from poultry production.

Cloacael Carriage and Multidrug Resistance Escherichia coli O157:H7 from Poultry Farms, Eastern Ethiopia

A cross-sectional study was carried out to determine antimicrobial drug resistance patterns of E. coli O157:H7 isolates and estimate the level of the pathogen. A total of 194 cloacae swab samples were collected randomly in two poultry farms. Standard cultural, biochemical, and serological (latex agglutination) methods were used to isolate E. coli O157:H7. The isolates were subjected to antimicrobial susceptibility testing using disc diffusion method. Out of 194 cloacae samples examined, 13.4% (n = 26) were found to be positive for E. coli O157:H7. The finding indicated differences in E. coli O157:H7 infection among the different risk factors. Chicken from Adele Poultry Farm showed higher E. coli O157:H7 infection (OR = 3.89) than Haramaya University poultry farm and young birds had more infection (OR = 4.62) than adult birds. Of the total 14 antimicrobials included in the panel of study, the susceptibility results were varied with 96.15% and 0% E. coli O157:H7 isolates expressing resistance to erythromycin, clindamycin, spectinomycin, and ciprofloxacin, respectively. Multidrug resistance to more than two antimicrobial agents was detected in 24 (92.30%) of the isolates. The study showed high presence of antimicrobial resistant isolates of E. coli O157:H7. Further study is required to better understand the ecology and evolution of bacterial resistance to antimicrobial agents.

Prevalence of antimicrobial resistance in enteric Escherichia coli from domestic pets and assessment of associated risk markers using a generalized linear mixed model

Antimicrobial resistance (AMR) is a growing global public health problem, which is caused by the use of antimicrobials in both human and animal medical practice. The objectives of the present cross-sectional study were as follows: (1) to determine the prevalence of resistance in Escherichia coli isolated from the feces of pets from the Porto region of Portugal against 19 antimicrobial agents and (2) to assess the individual, clinical and environmental characteristics associated with each pet as risk markers for the AMR of the E. coli isolates. From September 2009 to May 2012, rectal swabs were collected from pets selected using a systematic random procedure from the ordinary population of animals attending the Veterinary Hospital of Porto University. A total of 78 dogs and 22 cats were sampled with the objective of isolating E. coli. The animals' owners, who allowed the collection of fecal samples from their pets, answered a questionnaire to collect information about the markers that could influence the AMR of the enteric E. coli. Chromocult tryptone bile X-glucuronide agar was used for E. coli isolation, and the disk diffusion method was used to determine the antimicrobial susceptibility. The data were analyzed using a multilevel, univariable and multivariable generalized linear mixed model (GLMM). Several (49.7%) of the 396 isolates obtained in this study were multidrug-resistant. The E. coli isolates exhibited resistance to the antimicrobial agent's ampicillin (51.3%), cephalothin (46.7%), tetracycline (45.2%) and streptomycin (43.4%). Previous quinolone treatment was the main risk marker for the presence of AMR for 12 (ampicillin, cephalothin, ceftazidime, cefotaxime, nalidixic acid, ciprofloxacin, gentamicin, tetracycline, streptomycin, chloramphenicol, trimethoprim-sulfamethoxazole and aztreonam) of the 15 antimicrobials assessed. Coprophagic habits were also positively associated with an increased risk of AMR for six drugs, ampicillin, amoxicillin-clavulanic acid, cephamycin, ciprofloxacin, streptomycin, and trimethoprim-sulfamethoxazole. In summary, pets with a record of one or more previous quinolone treatments and exhibiting coprophagic habits were at an increased risk of harboring multidrug-resistant E. coli strains in their feces compared to pets without these characteristics. AMR is a serious global problem, and assessing the risk markers for the presence of drug-resistant bacteria in pets, a very close source of resistance determinants to humans, is essential for the implementation of safe handling procedures for companion animals and for the prudent selection of antimicrobial compounds in veterinary practice.

Oxytetracycline and penicillin-G residues in cattle slaughtered in south-western Nigeria: implications for livestock disease management and public health

After the discovery of indiscriminate antibiotic use in ready-for-slaughter cattle in south-western Nigeria, 90 tissue samples from randomly selected slaughtered cattle were evaluated for oxytetracycline and penicillin-G residues using high performance liquid chromatography and the data analysed by one-way Analysis of variance (ANOVA). The findings revealed residues of oxytetracycline (kidney: 9.47 µ/kg ± 3.24 µ/kg; liver: 12.73 µ/kg ± 4.39 µ/kg; muscle: 16.17 µ/kg ± 5.52 µ/kg) and penicillin-G (kidney: 6.27 µ/kg ± 2.46 µ/kg; liver: 8.5 µ/kg ± 2.80 µ/kg; muscle: 11.67 µ/kg ± 2.94 µ/kg) in all tissues screened. Significantly high levels (oxytetracycline: F = 16.77; penicillin-G: F = 29.38) were, however, found in muscles, followed by liver and then kidney – findings confirming recent antibiotic administration to the animals before slaughter. The dietary intakes through the tissues screened were 0.024% (oxytetracycline) and 0.017% (penicillin-G) of the acceptable daily intake (ADI). Although the concentrations in the tissues screened were below the maximum residue limits despite recent administration of these antibiotics before slaughter, the lower concentrations are suggestive of the probable low dosages often administered by those involved in indiscriminate use of antibiotics. This therefore raises serious concerns for the livestock industry as well as human health, given the resultant emergence and spread of resistant strains of bacterial pathogens that could ensue from prolonged use of low dosages of antibiotics. Additionally, the lower concentrations of the daily intakes notwithstanding, the plausible exposure to these antibiotics from other food sources is a cause for concern. Since antimicrobial misuse and its consequent effects are not just a problem limited to Nigeria but also a concern in sub-Saharan Africa, the need for national and international stakeholder intervention is emphasised.

Co-selection may explain high rates of ciprofloxacin non-susceptible Escherichia coli from retail poultry reared without prior fluoroquinolone exposure

Australia has never permitted fluoroquinolone use in food-producing animals. We examined local retail poultry for contamination with fluoroquinolone non-susceptible Escherichia coli, then explored the hypothesis that their presence may be due to co-selection of resistance determinants. Between August and November 2010, samples from 30 locally produced, uncooked retail poultry carcasses from four different processing centres underwent selective enrichment culture for ciprofloxacin non-susceptible E. coli. Their chromosomal- and plasmid-mediated resistance determinants were characterized, and phylogenetic analysis and transformation experiments were performed. Unexpectedly, we found nine (30 %) of our small collection of poultry samples carried fluoroquinolone non-susceptible E. coli of which nearly half possessed aac(6')-Ib-cr, a novel plasmid-mediated gene encoding an aminoglycoside acetylating enzyme that also confers fluoroquinolone resistance. All nine isolates were co-resistant to amoxicillin, gentamicin, tetracycline and trimethoprim/sulfamethoxazole--all antibiotic classes that are registered for use in poultry reared for food production within Australia. Their unique phylogenetic relatedness suggested clonal dissemination driven by non-fluoroquinolone selective pressures. aac(6')-Ib-cr was successfully transformed and selected for using non-fluoroquinolone antibiotic pressure. Vertical and perhaps horizontal co-selection may be contributing to the emergence of fluoroquinolone resistance in poultry and could play a similar role in the human setting. This suggests that preservation of the usefulness of fluoroquinolones may require more than just restriction of their use in isolation from other interventions.

Antimicrobial resistance in selected bacteria from poultry

This paper reviews the present state of antimicrobial resistance (AMR) in the zoonotic bacteria Salmonella, Campylobacter jejuni and Campylobacter coli, and in Escherichia coli from chickens and turkeys. For Salmonella, the frequencies and patterns of AMR vary depending on time, region, serovar, the particular farm, layers versus broilers, and the antimicrobial agent. There is usually a higher frequency of AMR in Salmonella from turkeys compared with Salmonella from chickens. Clonal and horizontal transmission of AMR occur and there is concern about the spread of transmissible plasmids that encode extended spectrum cephalosporinases. Resistance to fluoroquinolones is generally low. For Campylobacter, resistance to tetracycline is usually at moderate to high frequency, resistance to quinolones/fluoroquinolones varies from low to high, and resistance to macrolides is usually low. There are high levels of fluoroquinolone resistance in some countries. Avian pathogenic E. coli are often highly resistant, especially to tetracycline, streptomycin, and sulfonamides. Plasmid-mediated resistance is common. High levels of resistance to ciprofloxacin have been reported from China. Commensal E. coli from poultry have similar patterns of resistance but at lower frequencies. Integron associated resistance occurs commonly in Salmonella and E. coli but has not been detected in Campylobacter.

Evolution of resistance in poultry intestinal Escherichia coli during three commonly used antimicrobial therapeutic treatments in poultry

The resistance rates of intestinal Escherichia coli populations from poultry were determined during treatment and withdrawal period with 3 antimicrobial agents commonly used as therapeutics in poultry medicine. A total of 108 chickens were considered: 18 were treated orally with enrofloxacin, 18 with doxycycline, and 18 with sulfonamides, whereas another 18 chickens were maintained as controls for each antimicrobial group. Fecal samples were taken during the treatment and after the withdrawal period, and E. coli were isolated through Fluorocult media plating. A total of 648 E. coli strains (216 per antimicrobial tested) were isolated and identified though biochemical methods. Minimal inhibitory concentrations to the antimicrobials used were also determined using a broth microdilution method. The resistance rates of intestinal E. coli to all of the antimicrobials tested significantly increased during the course of the therapeutic treatment. In addition, significant differences (P = 0.0136) in resistance rates persisted between the intestinal E. coli of the enrofloxacin-treated and control batches until the end of the withdrawal period, but this difference was not observed for the cases of doxycycline or sulfonamides treatments. Antimicrobial use in poultry medicine seems to select for antimicrobial-resistant strains of pathogenic bacterial species such as E. coli. In some cases, the higher frequencies of resistant strains may persist in the avian intestinal tract until the end of the withdrawal period, when it is legal to use these animals for human consumption.