Faecal carriage of extended spectrum beta-lactamase (ESBL) and New Delhi metallo beta-lactamase(NDM) producing Escherichia coli between piglets and pig farmworkers

VirBR, a transcription regulator, promotes IncX3 plasmid transmission, and persistence of blaNDM-5 in zoonotic bacteria

IncX3 plasmids carrying the New Delhi metallo-β-lactamase-encoding gene, blaNDM-5, are rapidly spreading globally in both humans and animals. Given that carbapenems are listed on the WHO AWaRe watch group and are prohibited for use in animals, the drivers for the successful dissemination of Carbapenem-Resistant Enterobacterales (CRE) carrying blaNDM-5-IncX3 plasmids still remain unknown. We observe that E. coli carrying blaNDM-5-IncX3 can persist in chicken intestines either under the administration of amoxicillin, one of the largest veterinary β-lactams used in livestock, or without any antibiotic pressure. We therefore characterise the blaNDM-5-IncX3 plasmid and identify a transcription regulator, VirBR, that binds to the promoter of the regulator gene actX enhancing the transcription of Type IV secretion systems (T4SS); thereby, promoting conjugation of IncX3 plasmids, increasing pili adhesion capacity and enhancing the colonisation of blaNDM-5-IncX3 transconjugants in animal digestive tracts. Our mechanistic and in-vivo studies identify VirBR as a major factor in the successful spread of blaNDM-5-IncX3 across one-health AMR sectors. Furthermore, VirBR enhances the plasmid conjugation and T4SS expression by the presence of copper and zinc ions, thereby having profound ramifications on the use of universal animal feeds.

Genomic Profiling of Multidrug-Resistant Swine Escherichia coli and Clonal Relationship to Human Isolates in Peru

The misuse of antibiotics is accelerating antimicrobial resistance (AMR) in Escherichia coli isolated from farm animals. The genomes of ten multidrug-resistant (MDR) E. coli isolates from pigs were analyzed to determine their sequence types, serotypes, virulence, and AMR genes (ARGs). Additionally, the relationship was evaluated adding all the available genomes of Peruvian E. coli from humans using the cgMLST + HierCC scheme. Two aEPEC O186:H11-ST29 were identified, of which H11 and ST29 are reported in aEPEC isolates from different sources. An isolate ETEC-O149:H10-ST100 was identified, considered a high-risk clone that is frequently reported in different countries as a cause of diarrhea in piglets. One ExPEC O101:H11-ST167 was identified, for which ST167 is an international high-risk clone related to urinary infections in humans. We identified many ARGs, including extended-spectrum β-lactamase genes, and one ETEC harboring the mcr-1 gene. CgMLST + HierCC analysis differentiated three clusters, and in two, the human isolates were grouped with those of swine in the same cluster. We observed that Peruvian swine MDR E. coli cluster with Peruvian E. coli isolates from healthy humans and from clinical cases, which is of great public health concern and evidence that AMR surveillance should be strengthened based on the One Health approach.

Meta-Analysis of the Prevalence of Porcine Zoonotic Bacterial Pathogens in India: A 13-Year (2010-2023) Study

The presence of bacterial pathogens such as Brucella spp., Clostridium spp., E. coli, Listeria monocytogenes, Salmonella spp., Staphylococcus spp., and Streptococcus suis not only hampers pig production but also carries significant zoonotic implications. The present study aims to conduct a comprehensive meta-analysis spanning over 13 years (2010-2023) to ascertain the prevalence of these zoonotic bacterial pathogens in Indian pig populations. The study seeks to synthesize data from diverse geographic regions within India and underscores the relevance of the One Health framework. A systematic search of electronic databases was meticulously performed. Inclusion criteria encompassed studies detailing zoonotic bacterial pathogen prevalence in pigs within India during the specified timeframe. Pertinent information including authors, publication year, geographical location, sampling techniques, sample sizes, and pathogen-positive case counts were meticulously extracted. The meta-analysis of zoonotic bacterial pathogens in Indian pig populations (2010-2023) unveiled varying prevalence rates: 9% Brucella spp., 22% Clostridium spp., 19% E. coli, 12% Listeria monocytogenes, 10% Salmonella spp. and Streptococcus suis, and 24% Staphylococcus spp. The application of random effects further revealed additional variability: 6% Brucella spp., 23% Clostridium spp., 24% E. coli, 14% Listeria monocytogenes, 10% Salmonella spp. and Streptococcus suis, and 35% Staphylococcus spp. Notably, the observed heterogeneity (I2) varied significantly from 87% to 99%. The meta-analysis findings underscore the pervasive nature of these diseases throughout India's pig populations, accentuating the substantial impact of these pathogens on pig health and the potential for zoonotic transmission. The present study reinforces the importance of the adoption of a comprehensive One Health approach that acknowledges the intricate interplay between animal, human and environmental health.

Genetic diversity and risk factor analysis of drug-resistant Escherichia coli recovered from broiler chicken farms

A total of 38 Escherichia coli isolates were recovered from 120 samples collected from various sources of broiler chicken farms (n = 10 each) in Andhra Pradesh and Telangana states. Though the recovered E. coli isolates were found variably resistant to the tested antibiotics, all the tested isolates were susceptible to meropenem. Alarming multi-drug resistance (MDR) was observed (34/38) among the recovered isolates, wherein antibiotic-resistant genes (bla_TEM, bla_SHV, and tetA) were detected, except for bla_CTX-M-9. The heatmap with cluster analysis exhibited that majority of the E. coli isolates recovered from different sources and regions clustered together based on their phenotypic resistance suggesting co-sharing of resistance. However, the pulsed-field gel electrophoresis (PFGE) typing revealed an extremely diverse genotypic profile. Further, a significant statistical association was not observed between hypothesized risk factors and recovered MDR- E. coli isolates from various sources, although a significant statistical association between antibiotic resistance with large flock size, poor biosecurity practices, poor workers' hygiene, and poor disinfection practices was noticed. Since the study highlighted an alarming level of drug resistance among the recovered E. coli isolates, further in-depth research in similar veins is required to ensure the prudent use of antimicrobials in the poultry sector and the implementation of an antimicrobial surveillance system.

Global Distribution of Extended Spectrum Cephalosporin and Carbapenem Resistance and Associated Resistance Markers in Escherichia coli of Swine Origin - A Systematic Review and Meta-Analysis

Third generation cephalosporins and carbapenems are considered critically important antimicrobials in human medicine. Food animals such as swine can act as reservoirs of antimicrobial resistance (AMR) genes/bacteria resistant to these antimicrobial classes, and potential dissemination of AMR genes or resistant bacteria from pigs to humans is an ongoing public health threat. The objectives of this systematic review and meta-analysis were to: (1) estimate global proportion and animal-level prevalence of swine E. coli phenotypically resistant to third generation cephalosporins (3GCs) and carbapenems at a country level; and (2) measure abundances and global distribution of the genetic mechanisms that confer resistance to these antimicrobial classes in these E. coli isolates. Articles from four databases (CAB Abstracts, PubMed/MEDLINE, PubAg, and Web of Science) were screened to extract relevant data. Overall, proportion of E. coli resistant to 3GCs was lower in Australia, Europe, and North America compared to Asian countries. Globally, <5% of all E. coli were carbapenem-resistant. Fecal carriage rates (animal-level prevalence) were consistently manifold higher as compared to pooled proportion of resistance in E. coli isolates. bla_CTX–M were the most common 3GC resistance genes globally, with the exception of North America where bla_CMY were the predominant 3GC resistance genes. There was not a single dominant bla_CTX–M gene subtype globally and several bla_CTX–M subtypes were dominant depending on the continent. A wide variety of carbapenem-resistance genes (bla_{NDM–, VIM–, IMP–, OXA–48}, _andKPC–) were identified to be circulating in pig populations globally, albeit at very-low frequencies. However, great statistical heterogeneity and a critical lack of metadata hinders the true estimation of prevalence of phenotypic and genotypic resistance to these antimicrobials. Comparatively frequent occurrence of 3GC resistance and emergence of carbapenem resistance in certain countries underline the urgent need for improved AMR surveillance in swine production systems in these countries.

Effect of Intramuscularly Administered Oxytetracycline or Enrofloxacin on Vancomycin-Resistant Enterococci, Extended Spectrum Beta-Lactamase- and Carbapenemase-Producing Enterobacteriaceae in Pigs

Simple Summary

Nowadays, there is great concern about the prevalence of multidrug resistant bacteria in food-producing animals since they are potential sources of transmission to humans. The aim of this work was to evaluate the effect of two antibiotics (oxytetracycline and enrofloxacin) treatments in pigs on resistant bacteria that are considered a threat to public health. This study highlights that the use of oxytetracycline or enrofloxacin in food-producing animals could select resistant bacteria in pig faeces. Special care should be taken to avoid faecal contamination of carcasses during slaughter.

Abstract

Nowadays, there is a great concern about the prevalence of multidrug resistant Enterococcus spp. and Enterobacteriaceae in food-producing animals. The aim of this work was to evaluate the effect of oxytetracycline or enrofloxacin treatment on vancomycin-resistant enterococci (VRE), extended spectrum β-lactamase (ESBL) and carbapenemase-producing Enterobacteriaceae in pigs. A total of 26 piglets were received and distributed in three groups. Group 1 was treated with enrofloxacin (N = 12), group 2 with oxytetracycline (N = 10) and group 3 did not receive any treatment (control group) (N = 4). A higher number of vancomycin-resistant E. faecium were recovered compared to E. faecalis. In the pigs treated with enrofloxacin, vancomycin resistant E. faecium was found in a higher percentage of animals than in the control group. ESBL-producing E. coli was not detected in rectal samples from control animals. However, it was detected in 17–20% of animals treated with oxytetracycline on days 6 to 17 and in 17–50% of the animals treated with enrofloxacin. Carbapenemase-producing E. coli was isolated in animals treated with oxytetracycline, but not in animals treated with enrofloxacin or in the control group. This study highlights that the use of oxytetracycline or enrofloxacin in food-producing animals could select ESBL and carbapenemase-producing E. coli. Further studies shall be needed to validate the results obtained, considering a more robust and extended experimental design.

Multi-drug resistant (MDR), extended spectrum beta-lactamase (ESBL) producing and carbapenem resistant Escherichia coli in rescued Sloth bears (Melursus ursinus), India

The study reports the multi-drug resistant (MDR), extended spectrum beta-lactamase (ESBL) producing and carbapenem resistant Escherichia coli (CRE) isolated from rescued sloth bear (Melursus ursinus), India. Non-duplicate faecal samples from 21 adult rescued sloth bears were collected at once during 2015-2016 and processed for isolation of E. coli and antibacterial susceptibility pattern. From 21 samples, 45 E. coli were isolated and on phenotypic screening, 23 were MDR, 17 were ESBL producers, and five were carbapenem-resistant (CR). Three E. coli isolates (6.67%, 3/45) showed no resistance, however 42 isolates (93.33%, 42/45) exhibited resistant to at least one antibiotics. The MDR isolates carried beta-lactamase, chloramphenicol, aminoglycosides, tetracycline, fluroquinolone, and sulphadimidine resistance genes. All the phenotypic ESBL producing isolates harbored blaCTX-M genes. On genotypic screening, three CRE (60.0%, 3/5) were positive for blaNDM carbapenemase gene and efflux pump-mediated carbapenem resistance was detected in two CRE isolates (40.0%, 2/5) which were negative for carbapenemase genes. The CRE isolates (n = 5) also co-harbored AMR genes like blaTEM-1, blaAmpC, qnrA, qnrB, qnrS, tetA, tetB and sulI. Virulence screening of the resistant isolates detected the presence of Stx1(n = 1), Stx2 (n = 3), eaeA (n = 4) and hlyA (n = 3) genes. Plasmid incompatibility (Inc) typing revealed that two isolates harboured blaNDM-5 gene on Incl1 and one isolate on IncF plasmid. Apart from the NDM gene, the plasmids also carried tetracycline, beta-lactamase and quinolone resistance genes. The plasmid multilocus sequence typing (pMLST) of the E. coli Incl1 plasmid showed the Sequence Type (ST) 297. This appears to be the first report of MDR, ESBL producing and blaNDM-5 genes on Incl1 and IncF plasmids from rescued sloth bear.