Genotypic characterization of ESBL-producing E. coli from imported meat in South Korea

Prevalence of the blaCTX-M and blaTEM genes among extended-spectrum beta lactamase-producing Escherichia coli isolated from broiler chickens in Indonesia

Introduction

Infections of humans and animals by multidrug resistant bacteria are increasing because of the inappropriate use of antibiotics. Disease management may be more challenging if Escherichia coli produce extended-spectrum beta-lactamase (ESBL), which could cause resistance to aztreonam and third-generation cephalosporins. This study was aimed at determining the prevalence of the blaCTX-M and blaTEM genes among ESBL-producing E. coli isolated from broiler chickens in Indonesia.

Material and Methods

A total of 115 broiler cloacal swab samples were obtained from 22 farms and studied for the presence of E. coli. The isolates were identified using approved standard methods and were purified on eosin methylene blue agar media. The E. coli isolates were subjected to sensitivity testing using beta-lactam antibiotics, and ESBL production was confirmed by a double-disc synergy test. The presence of the blaCTX-M and blaTEM genes was identified using a PCR.

Results

It was found that 99/115 (86.1%) of the isolated E. coli were resistant to beta-lactam antibiotics and 34/115 (29.6%) of them were phenotypically detected to be ESBL producers. Of the 34 isolates that were confirmed ESBL producers, 32/34 (94.1%) of them harboured the blaCTX-M and 13/34 (38.2%) the blaTEM genes. The blaCTX-M and blaTEM genes were detected together in 12/34 (35.3%) isolates.

Conclusion

This study discovered that broiler chickens are possible reservoirs of ESBL-producing E. coli that may infect humans. Thus, a committed public health education campaign is recommended in order to mitigate the potential threat to human health.

Comparative molecular profiling of antimicrobial resistance and phylogenetic characterization of multidrug-resistant Escherichia coli isolated from meat sources in 2009 and 2021 in Japan

The global spread of antimicrobial resistance (AMR) is alarming. Escherichia coli is a Gram-negative bacterium that causes healthcare-associated infections and is a major threat to public health. Currently, no comprehensive antimicrobial surveillance of multidrug-resistant E. coli of diverse phylogroups along the meat value chain has been implemented in Higashihiroshima, Japan. Therefore, by employing the One Health approach, 1183 bacterial isolates, including 303 recovered from meat samples in 2009, were screened for the presence of antimicrobial resistance determinants using multiplex PCR and DNA sequencing techniques. Seventy-seven non-duplicate E. coli isolates that harbored AMR genes were subjected to antimicrobial susceptibility testing and the detection of integrons. Phylogenetic characterization, which has not been previously investigated, was used to assign E. coli to one of the eight phylogroups. Twenty-six out of 33 (78.8%) and 34 out of 44 (77.3%) E. coli isolates from 2009 and 2021 exhibited multidrug resistance (MDR) phenotypes, respectively. The most common clinical resistance was observed against ampicillin, tetracycline, kanamycin, sulfamethoxazole/trimethoprim, cefotaxime, and chloramphenicol. Overall, 22.1% (17/77) of the E. coli isolates carried extended-spectrum β-lactamase (ESBL)-encoding genes and showed the ESBL-resistant phenotypes. For the two isolation years, AmpC/ESBL prevalence decreased from 42.4% in 2009 to 20.5% in 2021. The identified AMR genes included bla_CTX-M-1, bla_CTX-M-2, bla_CTX-M-14, bla_CTX-M-15, and bla_SHV-12 (ESBL-types); bla_SHV-1, bla_TEM-1, bla_TEM-135, and bla_TEM-176 (narrow-spectrum types); bla_CMY-4, bla_ADC-32, bla_ADC-216, bla_ACT-48, and bla_ACT-51 (AmpC types); and integrons. All E. coli isolates were negative for carbapenemase-encoding genes, whereas one isolate from 2009 carried mcr-5.1 allele. Approximately 52% of E. coli isolates identified in 2009 were assigned to phylogroup A compared to the 20.5% in 2021. Notably, the highest proportions of E. coli phylogroups exhibiting MDR were groups A, B1, and F, suggesting that members of these groups are mostly associated with drug resistance. This study highlights the role of meat as a significant reservoir of MDR E. coli and potential source for transmission of AMR genes. Our findings emphasize the importance of continuous monitoring to track the changes in the spread of antimicrobial resistance in the food chain.

Evaluation of Retail Meat as a Source of ESBL Escherichia coli in Tamaulipas, Mexico

In recent decades, the appearance of a group of strains resistant to most β-lactam antibiotics, called extended-spectrum β-lactamases (ESBLs), has greatly impacted the public health sector. The present work aimed to identify the prevalence of ESBL-producing Escherichia coli strains in retail meat from northeast Tamaulipas. A total of 228 meat samples were obtained from 76 different stores. A prevalence of E. coli ESBL of 6.5% (15/228) was detected. All (15/15) of the ESBL strains were multiresistant. Altogether, 40% (6/15) of the strains showed the presence of class 1 integrons. The isolates identified with bla_CTX-M (20%) also showed co-resistance with the tet (A and B), str (A and B), and sul (2 and 3) genes. A total of 20% of the strains belonged to the B2 and D phylogroups, which are considered pathogenic groups. None of the ESBL-positive strains contained any of the virulence gene factors tested. The presence of ESBL-producing E. coli strains in meat indicates a potential risk to the consumer. Although most of these strains were classified as commensals, they were found to serve as reservoirs of multiresistance to antimicrobials and, therefore, are potential routes of dispersion of this resistance to other bacteria.

Genome Assessment of Carbapenem- and Colistin-Resistant Escherichia coli from Patients in a Sentinel Hospital in China

Antimicrobial-resistant (AMR) pathogens are a significant threat to public health worldwide. However, the primary carrier of AMR genes, particularly against last-resort antibiotics, is still only partially studied in Chinese hospitals. In a sentinel hospital in China, we collected 157 E. coli strains from patients between January and July 2021. One bla_NDM-1-, nine bla_NDM-5-, and one mcr-1-positive E. coli recovered from inpatients were identified as resistant to meropenem and colistin. There are 37 virulence genes discovered in the 11 strains, including astA in strain EC21Z-147 (O128: H4), which belongs to the enteroaggregative E. coli (EAEC). The bla_NDM gene is distributed into distinct ST types, including ST48, ST616, ST410, ST711, and ST2003, while the mcr-1 gene was identified in ST117. The conjugative plasmids IncX3, IncI1-I, and IncI2 mediated the bla_NDM-5 and mcr-1 genes detected among inpatients. Notably, the youngest age at which mcr-1-positive E. coli has been reported was at one day old, in a child in which the strain is closely related to strains with animal origins. Hospitals are major environments for the spread and dissemination of critical virulence and AMR genes, which requires active monitoring systems at the genome level to surveil the spread of virulence and AMR.

Raw Meat Contaminated with Cephalosporin-Resistant Enterobacterales as a Potential Source of Human Home Exposure to Multidrug-Resistant Bacteria

The prevalence of cephalosporine-resistant (3GC-R) strains among United States community-related research samples ranged from 5.6 to 10.8%, while, in the European countries, it was 1.2% to 10.1%. Several studies suggest that meat of animal origin could be one of the reservoirs of 3GC-R bacteria. Here, 86 raw meat samples (turkey, pork, chicken and beef) were collected randomly and verified for the presence of 3GC-R bacteria. The 3GC-R bacteria were isolated, identified and characterized phenotypically (antibiotic resistance, motility and biofilm) and genotypically (repetitive-sequence-based rep-PCR) to elucidate any correlations with principal component analysis (PCA). From 28 3GC-R positive samples, 41 strains were isolated, from which the majority belonged to Serratia fonticola (39%), followed by Escherichia coli (19.5%), Enterobacter cloacae (17.1%) and Klebsiella pneumoniae (14.6%). The isolates of E. coli and S. fonticola presented diverse profiles in rep-PCR. Generally, 3GC-R strains were more resistant to antibiotics used in veterinary medicine than in human medicine. PCA derived from antibiotic resistance, motility and biofilm formation of S. fonticola and E. coli strains showed that resistance to beta-lactams was separated from the resistance to other antibiotic classes. Moreover, for the S. fonticola, E. coli and En. cloacae, the type of meat can create a specific tendency towards antibiotic resistance and phenotypic characteristics for S. fonticola, while these relationships were not found for other tested species.

Genomic characterization of antimicrobial resistance in mcr-carrying ESBL-producing Escherichia coli from pigs and humans

Whole-genome sequencing (WGS) was conducted to characterize mcr-carrying extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (n=7). These E. coli isolates originated from two pigs (TH2 and TH3) and two humans (TH8 and TH9) from Thailand, and three pigs from Lao PDR (LA1, LA2 and LA3). Four E. coli sequence types/serotypes - ST6833/H20 (TH2 and TH3), ST48/O160:H40 (TH8 and TH9), ST5708/H45 (LA1) and ST10562/O148:H30 (LA2 and LA3) - were identified. The plasmid replicon type IncF was identified in all isolates. The point mutations Ser31Thr in PmrA and His2Arg in PmrB were found concurrently in all isolates (colistin MIC=4-8 µg ml^-1). LA1 contained up to five point mutations in PmrB, and the colistin MIC was not significantly different from that for the other isolates. All mcr-1.1 was located in the ISApl1-mcr-1-pap2 element, while all mcr-3.1 was located in the TnAs2-mcr-3.1-dgkA-ISKpn40 element. The mcr-3.1 and bla _CTX-M-55 genes were co-localized on the same plasmid, which concurrently contained cml, qnrS1 and tmrB. The bla _CTX-M-55 and mcr-3.1 genes were located on conjugative plasmids and could be transferred horizontally under selective pressure from ampicillin or colistin. In conclusion, comprehensive insights into the genomic information of ESBL-producing E. coli harbouring mcr were obtained. As mcr-carrying ESBL-producing E. coli were detected in pigs and humans, a holistic and multisectoral One Health approach is required to contain antimicrobial resistance (AMR).

Characterization of qnrB-carrying plasmids from ESBL- and non-ESBL-producing Escherichia coli

BACKGROUND

Escherichia coli carrying clinically important antimicrobial resistances [i.e., against extended-spectrum-beta-lactamases (ESBL)] are of high concern for human health and are increasingly detected worldwide. Worryingly, they are often identified as multidrug-resistant (MDR) isolates, frequently including resistances against quinolones/fluoroquinolones.

RESULTS

Here, the occurrence and genetic basis of the fluoroquinolone resistance enhancing determinant qnrB in ESBL-/non-ESBL-producing E. coli was investigated. Overall, 33 qnrB-carrying isolates out of the annual German antimicrobial resistance (AMR) monitoring on commensal E. coli (incl. ESBL-/AmpC-producing E. coli) recovered from food and livestock between 2013 and 2018 were analysed in detail. Whole-genome sequencing, bioinformatics analyses and transferability evaluation was conducted to characterise the prevailing qnrB-associated plasmids. Furthermore, predominant qnrB-carrying plasmid-types were subjected to in silico genome reconstruction analysis. In general, the qnrB-carrying E. coli were found to be highly heterogenic in their multilocus sequence types (STs) and their phenotypic resistance profiles. Most of them appeared to be MDR and exhibited resistances against up to ten antimicrobials of different classes. With respect to qnrB-carrying plasmids, we found qnrB19 located on small Col440I plasmids to be most widespread among ESBL-producing E. coli from German livestock and food. This Col440I plasmid-type was found to be highly conserved by exhibiting qnrB19, a pspF operon and different genes of unassigned function. Furthermore, we detected plasmids of the incompatibility groups IncN and IncH as carriers of qnrB. All qnrB-carrying plasmids also exhibited virulence factors and various insertion sequences (IS). The majority of the qnrB-carrying plasmids were determined to be self-transmissible, indicating their possible contribution to the spread of resistances against (fluoro)quinolones and other antimicrobials.

CONCLUSION

In this study, a diversity of different plasmid types carrying qnrB alone or in combination with other resistance determinants (i.e., beta-lactamase genes) were found. The spread of these plasmids, especially those carrying antimicrobial resistance genes against highest priority critically important antimicrobial agents, is highly unfavourable and can pose a threat for public health. Therefore, the dissemination pathways and evolution of these plasmids need to be further monitored.

High prevalence and antimicrobial susceptibility pattern of salmonella species and extended-spectrum β-lactamase producing Escherichia coli from raw cattle meat at butcher houses in Hawassa city, Sidama regional state, Ethiopia

BACKGROUND

Food-borne diseases related to the consumption of meat and its products had public health importance worldwide. The problem became worst in Ethiopia as the result of the tradition of eating raw cattle meat. Salmonella species and Escherichia coli are important food-borne pathogens associated with meat contamination. Hence the current study aimed to assess the prevalence and antimicrobial susceptibility of Salmonella species and Extended-spectrum β-lactamase producing Escherichia coli from raw cattle meat at butcher houses in Hawassa city, Sidama regional state, Ethiopia.

METHOD

A cross-sectional study was done on the prevalence and antimicrobial susceptibility pattern of Salmonella species and Extended-spectrum β-lactamase producing E.coli from raw cattle meat at butcher houses in Hawassa city from September to December 2020. Socio-demographic data were collected using a structured questionnaire and raw cattle meat and swab samples were collected from meat cutting equipment. The collected samples transported using icebox to Hawassa University College of Medicine and Health Sciences Microbiology Laboratory for identification. Samples were grown on different culture media and antimicrobial susceptibility tests were determined by using Kirby disc diffusion method. Data were entered and analyzed into SPSS version 23. Descriptive statistics were done and P-value < 0.05 was considered as statistically significant.

RESULT

The overall prevalence of salmonella and ESBL producing E.coli among 556 samples collected from 278 butcher houses was 36 (6.47%) (95% CI: 1.68-1.79) of which 13 (2.3%) were ESBL producing E.coli and 23(4.1%) were salmonella species. Poor hand washing practice (AOR = 2.208; 95% CI: 1.249-3.904) and touching birr while selling meat (AOR = 0.75; 95% CI: (0.433-1.299) were found to be significantly associated with the prevalence of salmonella species and E.coli on cattle meat. The isolates showed moderate levels of resistance (60-70%) against Amoxicillin/ clavulanic acid and high susceptibility (85-100%) against gentamicin, cotrimoxazole, ceftazidime, and tetracycline and the overall multidrug resistance was 33.3%.

CONCLUSION

This study revealed moderately high prevalence of salmonella and E.coli due to poor hygiene and sanitation practices in the butcher shops. Furthermore, the existence of ESBL producing E.coli isolates clearly indicate the possible threat to public health. Therefore, inspection by the right agencies must be implemented in order to prevent food-borne outbreaks and antimicrobial resistance.

Occurrence, Antimicrobial Resistance Profile, and Characterization of Extended-spectrum β-Lactamase-Producing Escherichia coli Isolates from Minced Meat at Local Markets in Thailand

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli exhibits strong multidrug resistance (MDR) to ampicillin and third-generation cephalosporins. This study examined the occurrence, antimicrobial susceptibility, and molecular genetic features of ESBL-producing E. coli isolates from three commonly consumed minced meat varieties, namely pork, chicken, and beef. In total, 150 samples were collected from 10 local markets in Thailand. ESBL-producing E. coli was identified in 78 samples (52%), and minced chicken meat was most contaminated (79.17%). The isolates exhibited potential susceptibility to amikacin (96.16%) and carbapenems (91-95%). However, ESBL-producing E. coli displayed strong resistance to ampicillin and cefpodoxime (100%) and high MDR to 3-5 antibiotic classes (94.87%). Most presumptive ESBL producers harbored ESBL resistance genes (97.44%), most commonly bla_TEM (78.21%). Indeed, our results demonstrated that raw minced meat has a high occurrence of ESBL-producing E. coli harboring ESBL resistance genes, highlighting the importance of implementation of sanitary handling practices to reduce microbial contamination in commercial meat as well as the need for consumer education on safe handling and cooking of meat products.

A review of antimicrobial resistance in imported foods

Antimicrobial resistance is one of the most serious threats to medical science. Food supply is recognized as a potential source of resistant bacteria, leading to the development of surveillance programs targeting primarily poultry, pork, and beef. These programs are limited in scope, not only in the commodities tested, but also in the organisms targeted (Escherichia coli, Salmonella, and Campylobacter); consequently, neither the breadth of food products available nor the organisms that may harbour clinically relevant and (or) mobile resistance genes are identified. Furthermore, there is an inadequate understanding of how international trade in food products contributes to the global dissemination of resistance. This is despite the recognized role of international travel in disseminating antimicrobial-resistant organisms, notably New Delhi metallo-beta-lactamase. An increasing number of studies describing antimicrobial-resistant organisms in a variety of imported foods are summarized in this review.

Clonal dissemination of Salmonella enterica serovar albany with concurrent resistance to ampicillin, chloramphenicol, streptomycin, sulfisoxazole, tetracycline, and nalidixic acid in broiler chicken in Korea

The aim of this study was to determine the prevalence, serovar distribution, antimicrobial resistance, and genotypic analyses of the dominating serovars of Salmonella in chickens from a national study in Korea. Between 2017 and 2018, a total of 550 chicken samples were collected from the top 12 integrated broiler chicken operations in Korea. Salmonella was isolated from 117 (32.5%) chicken feces and 19 (10.0%) retail chicken meat sources. Ten serovars were identified, and the most common Salmonella serovar was Salmonella ser. Albany (50 isolates, 36.8%), followed by S. Enteritidis (38 isolates, 27.9%), and S. Montevideo (23 isolates, 16.9%) isolated from 6, 10, and 6 operations, respectively. A total of 35 (25.7%) isolates were with the ACSSuTN (ampicillin, chloramphenicol, streptomycin, sulfisoxazole, tetracycline, and nalidixic acid) resistance pattern, with high prevalence of this resistance pattern in S. Albany (29 isolates, 58.0%). A total of 35 PFGE types were identified among Salmonella isolates of the serovars Albany, Enteritidis, Virchow, Montevideo, and Senftenberg, while 11 distinct types of PFGE patterns were found among S. Albany isolates, which showed an overall homology similarity of higher than 85%. Among these 35 PFGE types, 22 PFGE types corresponded to 32 isolates from samples limited to one operation, and the other 13 PFGE types corresponded to 72 isolates from samples widely distributed among different operations. These results highlighted rapid colony dissemination of multidrug-resistant S. Albany in chicken all over Korea after it first appeared in 2016; furthermore, the spread of Salmonella colonies between various integrated operations was common, and several operations played an important role in Salmonella carriage and transmission in Korea.

Potentially Pathogenic Multidrug-Resistant Escherichia coli in Lamb Meat

Extended-spectrum cephalosporin (ESC) resistance remains a threat since ESC are important antimicrobials used to treat infections in humans and animals. Escherichia coli is an important source of ESC-resistance genes, such as those encoding extended-spectrum β-lactamases (ESBLs). E. coli is a common commensal of lambs. Reports that contaminated food can be a source of ESC-resistant bacteria in humans and that ESBL-producing E. coli are found in sheep in Brazil led us to survey their presence in retail lamb meat. Twenty-five samples intended for human consumption were screened for ESC-resistant E. coli, and the isolates were characterized. IncI1-bla_CTX-M-8 and IncHI2-bla_CTX-M-2 were the main plasmids responsible for ESC resistance. The plasmids harbored common ESBL genes in Enterobacteriaceae from food-producing animals in Brazil. IncI1-bla_CTX-M-14 and IncF-bla_CTX-M-55 plasmids, associated with human infections, were also detected. Few CTX-M-producing E. coli have been clustered by typing methods, and some may be genetically pathogenic. The findings indicate the presence of diverse strains of E. coli, harboring important ESBL genes, in lamb meat in Brazil. Surveillance of ESC-resistant bacteria could reduce the spread of antimicrobial resistance through the food chain.

Extended-spectrum β-lactamase-producing Escherichia coli isolated from raw vegetables in South Korea

The increasing prevalence of oxyimino-cephalosporin-resistant Enterobacteriaceae has become a global concern because of their clinical impact on both human and veterinary medicine. The present study determined the prevalence, antimicrobial susceptibility, and molecular genetic features of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) isolates from raw vegetables. A total of 1324 samples were collected from two agricultural wholesale markets in Incheon, South Korea in 2018. The ESBL-EC strains were isolated from 0.83% (11/1324) samples, and all of them were resistant to ampicillin, piperacillin, cefazoline, cefotaxime, and nalidixic acid and yielded CTX-M-type ESBL, including CTX-M-14, CTX-M-15, CTX-M-55, CTX-M-27, and CTX-M-65. The isolates belonged to phylogenetic subgroups D (n = 5), A (n = 4), and B1 (n = 2). Multilocus sequence typing revealed nine known E. coli sequence types (STs), including ST10, ST38, ST69, ST101, ST224, ST349, ST354, ST2509, ST2847, and two new STs. Notably, ST69, ST10, ST38, and ST354 belong to the major human-associated extraintestinal pathogenic E. coli lineages. Our results demonstrate that ESBL-producing multidrug-resistant pathogens may be transmitted to humans through the vegetable intake, highlighting the importance of resistance monitoring and intervention in the One Health perspective.

The Aquatic Ecosystem, a Good Environment for the Horizontal Transfer of Antimicrobial Resistance and Virulence-Associated Factors Among Extended Spectrum β-lactamases Producing E. coli

One of the main public health problems nowadays is the increase of antimicrobial resistance, both in the hospital environment and outside it (animal environment, food and aquatic ecosystems, among others). It is necessary to investigate the virulence-associated factors and the ability of horizontal gene transfer among bacteria for a better understanding of the pathogenicity and the mechanisms of dissemination of resistant bacteria. Therefore, the objective of this work was to detect several virulence factors genes (fimA, papC, papG III, cnf1, hlyA and aer) and to determine the conjugative capacity in a wide collection of extended-spectrum β-lactamases-producing E. coli isolated from different sources (human, food, farms, rivers, and wastewater treatment plants). Regarding virulence genes, fimA, papC, and aer were distributed throughout all the studied environments, papG III was mostly related to clinical strains and wastewater is a route of dissemination for cnf1 and hlyA. Strains isolated from aquatic environments showed an average conjugation frequencies of 1.15 × 10⁻¹ ± 5 × 10⁻¹, being significantly higher than those observed in strains isolated from farms and food (p < 0.05), with frequencies of 1.53 × 10⁻⁴ ± 2.85 × 10⁻⁴ and 9.61 × 10⁻⁴ ± 1.96 × 10⁻³, respectively. The reported data suggest the importance that the aquatic environment (especially WWTPs) acquires for the exchange of genes and the dispersion of resistance. Therefore, specific surveillance programs of AMR indicators in wastewaters from animal or human origin are needed, in order to apply sanitation measures to reduce the burden of resistant bacteria arriving to risky environments as WWTPs.

Whole-Genome Sequencing-Based Characteristics in Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolated from Retail Meats in Korea

The spread of extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) has posed a critical health risk to both humans and animals, because resistance to beta-lactam antibiotics makes treatment for commonly infectious diseases more complicated. In this study, we report the prevalence and genetic characteristics of ESBL-ECs isolated from retail meat samples in Korea. A total of 1205 E. coli strains were isolated from 3234 raw meat samples, purchased from nationwide retail stores between 2015 and 2018. Antimicrobial susceptibility testing was performed for all isolates by a broth microdilution method, and the ESBL phenotype was determined according to the Clinical and Laboratory Standards Institute (CLSI) confirmatory method. All ESBL-EC isolates (n = 29) were subjected to whole-genome sequencing (WGS). The antimicrobial resistance genes, plasmid incompatibility types, E. coli phylogroups, and phylogenetic relations were investigated based on the WGS data. The prevalence of ESBL-ECs in chicken was significantly higher than that in other meat samples. The results in this study demonstrate that clonally diverse ESBL-ECs with a multidrug resistance phenotype were distributed nationwide, although their prevalence from retail meat was 0.9%. The dissemination of ESBL-ECs from retail meat poses a potential risk to consumers and food-handlers, suggesting that the continuous surveillance of ESBL-ECs in retail meat should be conducted at the national level.

Bonelli R, A. Penna B, P. Albuquerque J, M. Souza R, M. F. Cerqueira A. Antimicrobial Resistance in Farm Animals in Brazil: An Update Overview

In animal husbandry, antimicrobial agents have been administered as supplements to increase production over the last 60 years. Large-scale animal production has increased the importance of antibiotic management because it may favor the evolution of antimicrobial resistance and select resistant strains. Brazil is a significant producer and exporter of animal-derived food. Although Brazil is still preparing a national surveillance plan, several changes in legislation and timely programs have been implemented. Thus, Brazilian data on antimicrobial resistance in bacteria associated with animals come from official programs and the scientific community. This review aims to update and discuss the available Brazilian data on this topic, emphasizing legal aspects, incidence, and genetics of the resistance reported by studies published since 2009, focusing on farm animals and derived foods with the most global public health impact. Studies are related to poultry, cattle, and pigs, and mainly concentrate on non-typhoid Salmonella, Escherichia coli, and Staphylococcus aureus. We also describe legal aspects of antimicrobial use in this context; and the current occurrence of genetic elements associated with resistance to beta-lactams, colistin, and fluoroquinolones, among other antimicrobial agents. Data here presented may be useful to provide a better understanding of the Brazilian status on antimicrobial resistance related to farm animals and animal-derived food products.

Antimicrobial Resistance in Farm Animals in Brazil: An Update Overview

In animal husbandry, antimicrobial agents have been administered as supplements to increase production over the last 60 years. Large-scale animal production has increased the importance of antibiotic management because it may favor the evolution of antimicrobial resistance and select resistant strains. Brazil is a significant producer and exporter of animal-derived food. Although Brazil is still preparing a national surveillance plan, several changes in legislation and timely programs have been implemented. Thus, Brazilian data on antimicrobial resistance in bacteria associated with animals come from official programs and the scientific community. This review aims to update and discuss the available Brazilian data on this topic, emphasizing legal aspects, incidence, and genetics of the resistance reported by studies published since 2009, focusing on farm animals and derived foods with the most global public health impact. Studies are related to poultry, cattle, and pigs, and mainly concentrate on non-typhoid Salmonella, Escherichia coli, and Staphylococcus aureus. We also describe legal aspects of antimicrobial use in this context; and the current occurrence of genetic elements associated with resistance to beta-lactams, colistin, and fluoroquinolones, among other antimicrobial agents. Data here presented may be useful to provide a better understanding of the Brazilian status on antimicrobial resistance related to farm animals and animal-derived food products.

The threat of carbapenem-resistant bacteria in the environment: Evidence of widespread contamination of reservoirs at a global scale

Environmental reservoirs of antibiotic resistance (AR) are a growing concern that are gathering more attention as potential sources for human infection. Carbapenem-resistant Enterobacteriaceae (CRE) are extremely dangerous, as carbapenems are often drugs of last resort that are used to treat multi-drug resistant infections. Among the genes capable of conferring carbapenem resistance to bacteria, the most transferrable are those that produce carbapenemase, an enzyme that hydrolyzes carbapenems and other β-lactam antibiotics. The goal of this review was to comprehensively identify global environmental reservoirs of carbapenemase-producing genes, as well as identify potential routes of transmission to humans. The genes of interest were Klebsiella pneumoniae carbapenemase (KPC), New Delhi Metallo-β-lactamase (NDM), Oxacillinase-48-type carbapenemases (OXA-48), and Verona Integron-Mediated Metallo-β-lactamase (VIM). Carbapenemase genes have been reported in the environment on almost every continent. Hospital and municipal wastewater, drinking water, natural waterways, sediments, recreational waters, companion animals, wildlife, agricultural environments, food animals, and retail food products were identified as current reservoirs of carbapenemase-producing bacteria and genes. Humans have been recorded as carrying CRE, without recent admittance to a hospital or long-term care facility in France, Egypt, and China. CRE infections from the environment have been reported in patients in Montpellier, France and Cairo, Egypt. This review demonstrates the need for 1) comprehensive monitoring of AR not only in waterways, but also other types of environmental matrices, such as aerosol, dusts, periphyton, and surfaces in indoor environments; and 2) action to reduce the prevalence and mitigate the effects of these potentially deadly resistance genes. In order to develop an accurate quantitative model for environmental dimensions of AR, longitudinal sampling and quantification of AR genes and bacteria are needed, using a One Health approach.

The Role of Plasmids in the Multiple Antibiotic Resistance Transfer in ESBLs-Producing Escherichia coli Isolated From Wastewater Treatment Plants

We compared the diversity of extended-spectrum β-lactamases (ESBLs) producing Escherichia coli (E. coli) in wastewater of a municipal wastewater treatment plant. This was done by analyzing multiple antibiotic resistant phenotypes and genotypes. Also, we investigated the antibiotic resistance transfer mechanism of the plasmid by comparing the antibiotic resistance gene linked transfer using a conjugative test, and by analyzing the full-length DNA sequence of one plasmid. The results showed that 50 ESBLs-producing E. coli isolates were isolated from 80 wastewater samples at the rate of 62.5% (50/80), out of which 35 transconjugants were obtained with the multiple antibiotic resistant transfer rate as high as 70.0% (35/50). Multiple antibiotic resistance was shown in all transconjugants and donor bacteria, which were capable of resistance to 11 out of 15 kinds of antibiotics. Both transconjugants and donors were capable of resistance to the Ampicillin and Cefalotin at a rate of 100.00% (35/35), while the total antibiotic resistant spectrum of transconjugants narrowed at the rate of 94.29% (33/35) and broadened at the rate of 5.71% (2/35) after conjugate to the donor bacteria. PCR showed that the resistant genotypes decreased or remained unchanged when compared to donor bacteria with transconjugants while the blaTEM and blaCTX-M genes were transferred and linked at a rate of 100.00% (35/35) and the blaSHV gene was at the rate as high as 94.29% (33/35). However, the qnrS gene was transferred at a low rate of 4.17% (1/24). In addition, the major resistance gene subtypes were blaTEM- 1, blaSHV -11 , and blaCTX-M-15 according to sequencing and Blast comparison. Plasmid wwA8 is a closed-loop DNA molecule with 83157 bp, and contains 45 predicted genes, including three antibiotic resistant resistance genes, blaCTX-M-15 , blaTEM-1 and qnrS1, which can be transferred with E. coli in vitro. This study shows that E. coli isolated from wastewater was capable of transferring resistance genes and producing antibiotic resistant phenotypes. The plasmids containing different resistance genes in E. coli play an important role in the multiple antibiotic resistant transfer. Most importantly, antibiotic resistant resistance genes have different transfer efficiencies, the blaTEM and blaCTX-M genes transferred at a rate of 100.00% and linked transfer in all 35 transconjugants.