Highly Prevalent Multidrug-Resistant Campylobacter spp. Isolated From a Yellow-Feathered Broiler Slaughterhouse in South China

Prevalence, antimicrobial resistance and phylogenetic analysis of Salmonella contamination and transmission in yellow-feathered broiler hatcheries in China

Salmonella is a significant avian pathogen causing infectious diseases in poultry, with hatching playing a crucial role in its transmission. Despite its importance, systematic research on Salmonella transmission in hatcheries remains limited. This study evaluates the prevalence and antimicrobial resistance of Salmonella throughout all production stages in yellow-feathered broiler hatcheries: laying, egg storage, incubating, hatching, and post-hatch. We found an overall Salmonella prevalence of 11.3 %, with the pathogen detected in both chickens and environmental samples. The hatching stage was identified as the most critical for Salmonella spread. Moreover, Salmonella Pullorum is the predominant serotype (93.97 %). Notably, all Salmonella isolates exhibited multidrug resistance, with some resistant to polymyxin B (22.41 %) and tigecycline (12.93 %). Resistance rates were highest for nalidixic acid (100.00 %), sulfamethoxazole (100.00 %), ciprofloxacin (95.69 %), and ampicillin (94.83 %). Additionally, antimicrobial resistance plasmid replicons and virulence genes were identified in these isolates. Whole genome sequencing was performed on 43 S. Pullorum isolates, revealing that the majority were ST92 (90.70 %). Phylogenetic analysis classified the isolates into three lineages, with Lineage III being the most predominant (83.72 %). It was found that Salmonella isolates from chicks and eggs across various production stages were closely related, and those from the environment also showed significant similarity. This suggests that Salmonella in the environment may originate from chicks/eggs and spread to other stages. More attention should be paid to Salmonella contamination in yellow-feathered broiler hatcheries, and stringent measures should be taken to control the horizontal spread of Salmonella, in addition to blocking the pathway of vertical transmission.

A Decade of Antimicrobial Resistance in Human and Animal Campylobacter spp. Isolates

Objectives: Campylobacter spp. remain a leading cause of bacterial gastroenteritis worldwide, with resistance to antibiotics posing significant challenges to treatment and public health. This study examines profiles in antimicrobial resistance (AMR) for Campylobacter isolates from human and animal sources over the past decade. Methods: We conducted a comprehensive review of resistance data from studies spanning ten years, analyzing profiles in resistance to key antibiotics, ciprofloxacin (CIP), tetracycline (TET), erythromycin (ERY), chloramphenicol (CHL), and gentamicin (GEN). Data were collated from various regions to assess global and regional patterns of resistance. Results: The analysis reveals a concerning trend of increasing resistance patterns, particularly to CIP and TET, across multiple regions. While resistance to CHL and GEN remains relatively low, the high prevalence of CIP resistance has significantly compromised treatment options for campylobacteriosis. Discrepancies in resistance patterns were observed between human and animal isolates, with variations across different continents and countries. Notably, resistance to ERY and CHL showed regional variability, reflecting potential differences in antimicrobial usage and management practices. Conclusions: The findings underscore the ongoing challenge of AMR in Campylobacter, highlighting the need for continued surveillance and research. The rising resistance prevalence, coupled with discrepancies in resistance patterns between human and animal isolates, emphasize the importance of a One Health approach to address AMR. Enhanced monitoring, novel treatment strategies, and global cooperation are crucial for mitigating the impact of resistance and ensuring the effective management of Campylobacter-related infections.

Antibiotic resistance in Campylobacter jejuni and Campylobacter coli: significant contribution of an RND type efflux pump in erythromycin resistance

In this study, we aimed to determine the antibiotic resistance status of Campylobacter spp. isolated from human infections in our region, including the role of mechanisms involved in erythromycin resistance. Standard methods were used for the isolation, identification and antibiotic susceptibility testing of Campylobacter spp. isolates. Erythromycin-resistant mutants were selected from erythromycin-susceptible clinical isolates, and the erythromycin resistance mechanisms were investigated phenotypically by determining the erythromycin MICs of isolates in the presence and absence of the resistance nodulation cell division (RND) type efflux pump inhibitor, phenylalanine-arginine β-naphthylamide dihydrochloride (PAβN), and genotypically by determining ribosomal and cmeABC alterations using PCR and DNA sequence analysis. Campylobacter spp., including 184 C. jejuni and 20 C. coli in a two-year period, were the most frequently isolated gastrointestinal bacterial pathogens in our region. However, in both C. jejuni and C. coli, resistance to tetracycline and ciprofloxacin were found to be high, erythromycin resistance was especially high (20%) in C. coli. With a ribosomal alteration, A2075G, which was found to be associated with high-level erythromycin resistance in clinical isolates, PAβN significantly reduced the erythromycin MICs in both clinical isolates and mutants. An important finding of this study, while considering cmeABC operon, is the explanation of why erythromycin resistance is more common among C. coli than C. jejuni, bearing in mind the specific deletions and alterations in the intergenic region of the operon in all erythromycin-resistant C. coli isolates. Ultimately, these findings revealed the significant role of RND-type efflux activity in increased erythromycin MICs of the isolates.

Antimicrobial resistance patterns and genes of Campylobacter jejuni isolated from chickens in Pasuruan, Indonesia

Background

Poultry is one of the most prominent sources of Campylobacter jejuni, which is also a major means of transmission to people. Campylobacter jejuni contamination in chicken meat comes from chicken feces because it naturally exists in the intestines of chickens.

Aim

The purpose of this study is to identify the antibiotic resistance patterns and genes of C. jejuni, which was found in chickens in Pasuruan, Indonesia.

Methods

The samples used in this study were 200 contents of the small intestine of broiler chickens from 40 farms in Pasuruan Regency. The enriched sample was streaked on the selective media of modified charcoal cefoperazone deoxycholate agar containing the CCDA selective supplement. Antimicrobial susceptibility test utilizing the Kirby-Bauer diffusion test method in accordance with Clinical and Laboratory Standards Institute standards. The polymerase chain reaction (PCR) method was used to detect the (hipO), which encodes the C. jejuni strain, fluoroquinolone resistance (gyrA), beta-lactam resistance (blaOXA-61), and tetracycline resistance (tetO) genes.

Results

The findings revealed a 14% (28/200) prevalence of C. jejuni in the small intestine of broiler chickens. These isolates showed high resistance to enrofloxacin (92.9%). All isolates (100%) were susceptible to amoxicillin-clavulanate. The PCR results showed all C. jejuni isolates (100%) detected the gyrA gene, 96.4% detected the blaOXA-61 gene, and 50% detected the tetO gene.

Conclusion

The findings of antimicrobial resistance at a high level from the small intestine of broiler chickens illustrate the potential threat to human health. To lessen the effects now and in the future, coordinated and suitable action is needed, as well as steps to guarantee the poultry industry's economic survival and public health insurance.

Overview of Ecology and Aspects of Antibiotic Resistance in Campylobacter spp. Isolated from Free-Grazing Chicken Tissues in Rural Households

Rural households all over the world rear backyard chicken mainly for their own consumption and, to a lesser extent, for barter trade. These chickens represent a staple dish with numerous culinary variations and a cheap source of protein. Although some Campylobacter species, and particularly Campylobacter jejuni and Campylobacter coli, have been associated with industrial poultry carcasses, studies concerning the ecology of this genus in rural households do not exist. To assess the prevalence of Campylobacter species in the tissues of backyard chickens, samples were collected from birds Gallus domesticus bred in households in the rural area of Epirus (Greece), and Campylobacter strains were isolated by quantitative methods at 37 °C and 42 °C. In total, 256 strains were identified, belonging to 17 Campylobacter species, with C. jejuni and C. coli being the most prevalent. From the four ecological parameters studied (size of the flock, presence of small ruminants in the same household, presence of other poultry species in the same household, and feeding leftovers of the household), the size of the flock and the presence of small ruminants and/or pigs in the same household mostly affected the distribution of these strains. To study the phenotypical resistance against 14 antibiotics, 215 strains were selected. The results showed a high prevalence of multidrug-resistance (MDR) strains extending to all classes of antibiotics. Further genome analysis revealed the presence of genes coding resistance (blaOxA-61, tet(O), tet(A) cmeA, cmeB, cmeC, and gyrA (Thr-86-Ile mutation)), with the efflux pump CmeABC being the most prevalent. All antimicrobial resistance-encoded genes co-circulated, except for blaOXA-61, which moved independently. The minimum inhibitory concentration (MIC) values of two out of three antibiotics (representing different classes) were reduced when the strains tested were exposed to carbonyl cyanide 3-chlorophenylhydrazone (CCCP), a known efflux pump inhibitor. The same result was obtained with the addition of CCCP to the MIC values of bile salts. These results lead to the conclusion that Campylobacter species are present in an impressive diversity in backyard chicken tissues and that they exert a significant resistance to antibiotics, raising a potential danger for public health.

Fluorescence Resonance Energy Transfer (FRET)-Based Sensor for Detection of Foodborne Pathogenic Bacteria: A Review

Sensitive and rapid determination of foodborne pathogenic bacteria is of practical importance for the control and prevention of foodborne illnesses. Nowadays, with the prosperous development of fluorescence assays, fluorescence resonance energy transfer (FRET)-derived diagnostic strategies are extensively employed in quantitative analysis of different pathogenic bacteria in food-related matrices, which displays a rapid, simple, stable, reliable, cost-effective, selective, sensitive, and real-time way. Considering the extensive efforts that have been made in this field so far, we here discuss the up-to-date developments of FRET-based diagnostic approaches for the determination of key foodborne pathogens like Staphylococcus aureus, Escherichia coli, Vibrio parahaemolyticus, Salmonella spp., Campylobacter spp., and Bacillus cereus in complex food-related matrices. Moreover, the principle of this technology, the choosing standards of acceptor-donor pairs, and the fluorescence properties are also profiled. Finally, the current prospects and challenges in this field are also put forward.

First report of phenotypic and genotypic (blaOXA-61) beta-lactam resistance in Campylobacter jejuni from broilers in Indonesia

Background and Aim

Campylobacter is a zoonotic bacterium that is a major source of foodborne diseases. In humans, most cases of campylobacteriosis are caused by Campylobacter jejuni. Poultry is the main reservoir of Campylobacter for humans, because Campylobacter is part of the normal flora of the digestive tract of poultry. Antimicrobial resistance to several antibiotics in Campylobacter isolated from humans and food animals has increased rapidly. Beta-lactam is an antibiotic with a high prevalence of resistance in Campylobacter. This study aimed to investigate phenotypic and genotypic (blaOXA-61) beta-lactam resistance in C. jejuni from broilers in Indonesia.

Materials and Methods

A total of 100 samples of broiler intestinal contents were obtained from 10 broiler farms in Pasuruan Regency, Indonesia. Campylobacter jejuni was identified using conventional and polymerase chain reaction (PCR)-based methods. Phenotypic detection of beta-lactam resistance was performed using an antimicrobial susceptibility test with antibiotic disks of aztreonam, ampicillin, and amoxicillin-clavulanic acid. Genotypic detection by PCR was performed using the blaOXA-61 gene, which encodes beta-lactamase.

Results

Campylobacter jejuni was identified in 23% of the samples. Phenotypically, 100% (23/23) and 73.9% (17/23) C. jejuni isolates had high resistance to aztreonam and ampicillin, respectively, but all isolates were susceptible to amoxicillin-clavulanic acid. Genotypically, all isolates carried blaOXA-61, indicated by the presence of a 372-bp PCR product.

Conclusion

Campylobacter jejuni is highly resistant to beta-lactams and is a serious threat to human health. Resistance to beta-lactams should be monitored because beta-lactamase genes can be transferred between bacteria. Public awareness must also be increased on the importance of using antibiotics rationally in humans and animals.

Particle-size stratification of airborne antibiotic resistant genes, mobile genetic elements, and bacterial pathogens within layer and broiler farms in Beijing, China

The particle-size distribution of antimicrobial resistant (AMR) elements is crucial in evaluating their environmental behavior and health risks, and exposure to the fecal microbiome via particle mass (PM) is an important route of transmission of AMR from livestock to humans. However, few studies have explored the association between air and fecal AMR in farm environments from the perspective of particle-size stratification. We collected feces and PMs of different sizes from layer and broiler farms, quantified antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and human pathogenic bacteria (HPB) using Droplet digital PCR (ddPCR), and analyzed the bacterial communities based on 16S rRNA sequencing. The particle-size distributions of 16S rRNA and AMR elements were similar and generally increased with larger particle sizes in chicken farms. In broiler farms, we observed a bimodal distribution with two peaks at 5.8-9.0 μm and 3.3-4.7 μm. The dominant airborne bacterial phyla were Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes. The dominant phyla in the feces were the same as those in the air, but the order of relative abundance varied. The particle-size distributions of specific bacterial genera differed between the animal-farm types. Overall, the degree of association between feces and different particulates increased with increasing particle size. The microbial communities in the coarse particles were similar to those in fecal samples. Escherichia coli, Staphylococcus spp., Campylobacter spp., and sul 2 (sulfonamide ARGs) tended to attach to small particles. We highlight the particle size-specific relationship between fecal and air microbes involving ARGs, MGEs, and HPB and provide valuable information for comprehensively assessing the transmission of fecal microorganisms through the airpath and its environmental and occupational health risks.

Genetic characteristics, antimicrobial susceptibility, and virulence genes distribution of Campylobacter isolated from local dual-purpose chickens in central China

Food-borne antibiotic-resistant Campylobacter poses a serious threat to public health. To understand the prevalence and genetic characteristics of Campylobacter in Chinese local dual-purpose (meat and eggs) chickens, the genomes of 30 Campylobacter isolates, including 13 C. jejuni and 17 C. coli from Jianghan-chickens in central China, were sequenced and tested for antibiotic susceptibility. The results showed that CC-354 and CC-828 were the dominant clonal complexes of C. jejuni and C. coli, respectively, and a phylogenetic analysis showed that three unclassified multilocus sequence types of C. coli were more closely genetically related to C. jejuni than to other C. coli in this study. Of the six antibiotics tested, the highest resistance rates were to ciprofloxacin and tetracycline (100%), followed by lincomycin (63.3%), erythromycin (30.0%), amikacin (26.7%), and cefotaxime (20.0%). The antibiotic resistance rate of C. coli was higher than that of C. jejuni. The GyrA T86I mutation and 15 acquired resistance genes were detected with whole-genome sequencing (WGS). Among those, the GyrA T86I mutation and tet(O) were most prevalent (both 96.7%), followed by the blaOXA-type gene (90.0%), ant(6)-Ia (26.7%), aac(6')-aph(3'') (23.3%), erm(B) (13.3%), and other genes (3.3%). The ciprofloxacin and tetracycline resistance phenotypes correlated strongly with the GyrA T86I mutation and tet(O)/tet(L), respectively, but for other antibiotics, the correlation between genes and resistance phenotypes were weak, indicating that there may be resistance mechanisms other than the resistance genes detected in this study. Virulence gene analysis showed that several genes related to adhesion, colonization, and invasion (including cadF, porA, ciaB, and jlpA) and cytolethal distending toxin (cdtABC) were only present in C. jejuni. Overall, this study extends our knowledge of the epidemiology and antibiotic resistance of Campylobacter in local Chinese dual-purpose chickens.

Prevalence of the phenicol resistance gene fexA in Campylobacter isolated from the poultry supply chain

Florfenicol, an animal-specific broad-spectrum antibiotic, has been widely used in livestock and poultry breeding, which leads to the high antimicrobial resistance (AMR) of Campylobacter in food animals. Recently, a new florfenicol resistance gene, fexA, often located on various multidrug resistance genomic islands (MDRGIs) and confers resistance to various antimicrobial agents, was characterized in Campylobacter. However, the prevalence and genetic environments of fexA and its associated MDRGIs in Campylobacter in the poultry supply chain need further characterization. Here, a total of 111 (15.48 %) Campylobacter isolates (63 C. jejuni, 40 C. coli, 8 C. lari) were obtained from 717 samples from farms, slaughterhouses, and supermarkets. Both phenotypic and genotypic analyses indicated that the AMR of C. coli was significantly higher than that of C. jejuni. PCR amplification and whole genome sequencing showed that the fexA gene was present in 26 out of 35 florfenicol-resistant Campylobacter isolates. This gene was located in the tet(L)-fexA-tet(O) MDRGI. The fexA-harboring isolates detected in the above sources could be clustered into the same branch, indicating that they may have the same ancestor. In addition, the erm(B) gene was identified in 17 Campylobacter isolates, and the A2075G point mutation in the 23S rRNA gene occurred in 26 isolates, emphasizing the high resistance of Campylobacter to macrolides. In summary, these results indicate that fexA within the MDRGI of Campylobacter can be transmitted through bacteria in the animal-based food supply chain, and it is necessary to strengthen the monitoring of the prevalence and spread of fexA in foodborne Campylobacter spp.