Multi-drug resistant (MDR) Gram-negative pathogenic bacteria isolated from poultry in the Noakhali region of Bangladesh

Rapidly increasing antibiotic-resistant bacterial strains in Bangladesh's food and farm animals stem from the excessive and inappropriate use of antibiotics. To assess the prevalence of multi-drug resistant (MDR) Gram-negative bacteria in poultry chicks, we sought to isolate and identify strains carrying antimicrobial resistance genes. Isolation and identification involved biochemical tests, 16S rRNA sequencing, and PCR screening of species-specific genes. MDR patterns were evaluated using CLSI guidelines with seventeen antibiotics across twelve classes. Targeted gene sequences were amplified for the detection of Extended-spectrum β-Lactamase (ESBL), carbapenem, tetracycline, sulfonamide, and colistin resistance genes. Common isolates, such as Escherichia coli, Klebsiella pneumoniae, Proteus penneri, and Enterobacter hormaechei, exhibited average Multiple Antimicrobial Resistance (MAR) indices of 0.66, 0.76, 0.8, 0.84, and 0.81, 0.76, 0.84, 0.41 for broiler and layer chicken, respectively. Providencia stuartii and Salmonella enterica, exclusive to broiler samples, had MAR indices of 0.82 and 0.84, respectively. Additional isolates Morganella morganii, Aeromonas spp., and Wohlfahrtiimonas chitiniclastica were found in layers (Average MAR indices: 0.73, 0.71, and 0.91). Notably, M. morganii, E. hormaechei and W. chitiniclastica were identified for the first time in Bangladeshi poultry chicken, although their evolution is yet to be understood. In this study, Pan-drug resistance was observed in one P. stuartii (broiler) and one Aeromonas spp. (layer) with a MAR index 1, while all isolates exhibited MAR indices >0.2, indicating MDR. Antimicrobial resistance (AMR) gene screening identified blaTEM, blaSHV, tetA, and sul1 in a majority of the MDR strains. Interestingly, E. coli (lactose positive and negative) and E. hormaechei were exclusively found to possess the tetB gene. In addition, E. coli (lactose negative), Klebsiella pneumoniae, Enterobacter hormaechei, M. morganii, and P. stuartii were observed to carry the colistin-resistant mcr-1 gene, whereas sul2 was detected in E. coli (lactose positive and negative), E. hormaechei, P. stuartii, and P. penneri. These findings emphasize the health risk of our consumers of both broiler and layer chickens as they have turned into a potent reservoir of various AMR gene carrying MDR and Pan-drug resistant bacteria.

Distribution of extended-spectrum β-lactamase producing Escherichia coli genes in an integrated poultry-fish farming system in Bogor, Indonesia

Background and Aim

The excessive use of antimicrobials in livestock farming leads to the emergence and dissemination of antimicrobial-resistant organisms. This study aimed to detect extended-spectrum β-lactamase (ESBL)-producing Escherichia coli genes in integrated poultry-fish farms in Bogor, Indonesia.

Materials and Methods

A total of 256 samples were collected from six poultry-fish farms. One hundred and seventy-five chicken cloaca swabs, 60 fish skin swabs, six pond water samples, and 15 farmer's hand swabs. ESBL-producing E. coli was confirmed through double-disk diffusion. The specific primers and probe genes for quantitative polymerase chain reaction detection of ESBL-producing E. coli targeted blaTEM, blaCTX-M, blaSHV, and blaOXA-48 genes.

Results

Among the 256 samples tested, 145 (56.6%) were positive for E. coli, and 67.6% (98/145) were identified as ESBL-producing E. coli. The most ESBL-producing E. coli isolates were obtained from chicken cloaca (78.3%, 72/92), followed by pond water (66.7%, 4/6), fish skin (47.6%, 20/42), and farmer's hand swabs (40%, 2/5). About 100% of the isolates carried the genes blaTEM and blaCTX-M, whereas 17.3% and 24.5% carried blaSHV and blaOXA-48, respectively.

Conclusion

ESBL-producing E. coli genes were investigated in chicken cloaca, fish, pond water, and farmers' hands within an interconnected poultry-fish farming operation. The ESBL-producing E. coli in chickens can transfer resistant genes to aquatic environments. The transfer could harm other aquatic species and food chains, potentially threatening human health.

Characterization of Escherichia coli pathogenicity and drug resistance in yolk peritonitis

Yolk Peritonitis can lead to a rapid decline in egg production, which seriously affects the health of laying hens and the profitability of chicken farms. Escherichia coli (E. coli) is the most common cause of yolk peritonitis in laying hens. In this study, bacterial samples were collected from the ovaries and fallopian tubes of laying hens with suspected yolk peritonitis from a laying farm in Jiangsu Province, and their pathogenicity and drug resistance were investigated. Initially, morphological and biochemical detection methods were employed to isolate and identify the pathogenic bacteria. The results showed that a total of 16 strains of E. coli were isolated from laying hens with yolk peritonitis. Subsequently, the drug resistance and pathogenicity of a randomly selected E. coli strain were analyzed and predicted by genome sequencing technology, and the drug resistance of E. coli was verified by drug sensitivity test and PCR. Finally, the virulence was verified by infection experiment in mice. The study revealed that the egg-yolk peritonitis in laying hens was caused by E. coli infection, and the genome sequencing analysis revealed that the bacteria had multidrug resistance and high virulence. The drug susceptibility testing indicates that E. coli exhibited resistance to aminoglycosides, β-lactam, macrolides, fluoroquinolones, and sulfonamides. In this study, resistance genes including KdpE, aadA5, APH(3 ")-ID, APH(6)-ID, and TEM-1 were identified, and their expression levels varied across different stages of bacterial growth. The results of virulence analysis indicated a mortality rate of 50% in mice infected with E. coli at a concentration of 2.985 × 107 CFU/mL. E. coli infection resulted in damage to various tissues and organs in mice, with the intestinal tissue structure being the most severely affected. This study provides a reference for the study of drug resistance mechanisms in E. coli and provides valuable insights into the selection of drugs for the treatment of vitelline peritonitis.

Molecular characterization of antibiotic resistant Salmonella enterica across the poultry production chain in Costa Rica: A cross-sectional study

Antibiotic resistant Salmonella enterica are on the increase, worldwide. Given the scarcity of data, this study aimed to investigate its occurrence, virulence, and antibiotic resistance in Costa Rica's food chain. In total, 65 chicken meat- and 171 chicken caecal samples were collected and examined for Salmonella. High frequencies of Salmonella were found in chicken meat (58.5 %, n/N = 38/65) and poultry farms (38.0 %, n/N = 65/171). The majority of Salmonella from chicken meat (89.5 %, n/N = 34/38) and caecum samples (93.6 %, n/N = 59/63) exhibited multidrug resistance (MDR). Serovar Infantis was the most prevalent (94 %, n/N = 67/71), followed by serovars Anatum and Kentucky (3 %, n/N = 2/71). A pESI-like plasmid (92 %, n/N = 65/71) containing virulence and resistance markers was found in S. Infantis. Given the high prevalence of MDR Salmonella, this study emphasizes the need to enhance surveillance systems for foodborne pathogens and antimicrobial resistance in Costa Rica's food production chain.

Mechanisms of Pathogenic Escherichia coli Attachment to Meat

Escherichia coli are present in the human and animal microbiome as facultative anaerobes and are viewed as an integral part of the whole gastrointestinal environment. In certain circumstances, some species can also become opportunistic pathogens responsible for severe infections in humans. These infections are caused by the enterotoxinogenic E. coli, enteroinvasive E. coli, enteropathogenic E. coli and the enterohemorrhagic E. coli species, frequently present in food products and on food matrices. Severe human infections can be caused by consumption of meat contaminated upon exposure to animal feces, and as such, farm animals are considered to be a natural reservoir. The mechanisms by which these four major species of E. coli adhere and persist in meat postslaughter are of major interest to public health and food processors given their frequent involvement in foodborne outbreaks. This review aims to structure and provide an update on the mechanistic roles of environmental factors, curli, type I and type IV pili on E. coli adherence/interaction with meat postslaughter. Furthermore, we emphasize on the importance of bacterial surface structures, which can be used in designing interventions to enhance food safety and protect public health by reducing the burden of foodborne illnesses.

Diversity of antimicrobial-resistant bacteria isolated from Australian chicken and pork meat

Antimicrobial-resistant bacteria are frequently isolated from retail meat and may infect humans. To determine the diversity of antimicrobial-resistant bacteria in Australian retail meat, bacteria were cultured on selective media from raw chicken (n = 244) and pork (n = 160) meat samples obtained from all four major supermarket chains in the ACT/NSW, Australia, between March and June 2021. Antimicrobial susceptibility testing (AST) was performed for 13 critically and 4 highly important antibiotics as categorised by the World Health Organization (WHO) for a wide range of species detected in the meat samples. A total of 288 isolates underwent whole-genome sequencing (WGS) to identify the presence of antimicrobial resistance (AMR) genes, virulence genes, and plasmids. AST testing revealed that 35/288 (12%) of the isolates were found to be multidrug-resistant (MDR). Using WGS data, 232/288 (81%) of the isolates were found to harbour resistance genes for critically or highly important antibiotics. This study reveals a greater diversity of AMR genes in bacteria isolated from retail meat in Australia than previous studies have shown, emphasising the importance of monitoring AMR in not only foodborne pathogenic bacteria, but other species that are capable of transferring AMR genes to pathogenic bacteria.

Whole-genome sequencing and characterization of Escherichia coli human isolate DP033

The whole-genome sequence of Escherichia coli strain DP033 is reported here. DP033 was isolated from a human rectal specimen in Tilburg, the Netherlands. In silico analysis showed that DP033 possessed 36 virulence-related genes and is a presumptive extraintestinal pathogenic E. coli and uropathogenic E. coli strain.

Clonal diversity and zoonotic potential of MDR Escherichia coli isolated from poultry at different age intervals

1. A pool of 480 E. coli isolates of poultry (broilers and ducks) representing different time intervals (0, 10, 20 and 30 days) was selected for ribotyping and used to determine polymorphism of 16-23S ribosomal RNA intergenic space. All the isolates were multidrug-resistant (MDR).2. Out of these, 10 isolates were tested for MultiLocus Sequence Typing (MLST) among which novel allelic combinations and therefore new sequence types were identified in seven isolates.3. This work showed the changes in E. coli strains structure at farm level and individual bird level in host species raised on organised farms with similar parental lineage and environmental housing. The statistical results showed that the structure of variation is very different by farm, supporting a strong effect of location, which confirms the temporal clustering.4. There were significant differences between E. coli strains in chickens and ducks, indicating host specificity of the E. coli strains.5. Some of the pathogenic E. coli strains found using MLST belonged to ST735, ST2796 and a pandemic clone ST752 of ST10 clonal complex. The results strongly suggested the clonal expansion and establishment of specific MDR clones that have zoonotic relevance.

Extended-spectrum β-lactamase-producing E. coli from retail meat and workers: genetic diversity, virulotyping, pathotyping and the antimicrobial effect of silver nanoparticles

BACKGROUND

The spread of extended-spectrum β-lactamases (ESBL) producing E. coli from food animals and the environment to humans has become a significant public health concern. The objectives of this study were to determine the occurrence, pathotypes, virulotypes, genotypes, and antimicrobial resistance patterns of ESBL-producing E. coli in retail meat samples and workers in retail meat shops in Egypt and to evaluate the bactericidal efficacy of silver nanoparticles (AgNPs-H2O2) against multidrug resistant (MDR) ESBL-producing E. coli.

RESULTS

A total of 250 retail meat samples and 100 human worker samples (hand swabs and stool) were examined for the presence of ESBL- producing E. coli. Duck meat and workers' hand swabs were the highest proportion of ESBL- producing E. coli isolates (81.1%), followed by camel meat (61.5%). Pathotyping revealed that the isolates belonged to groups A and B1. Virulotyping showed that the most prevalent virulence gene was Shiga toxin 2 (stx2) associated gene (36.9%), while none of the isolates harbored stx1 gene. Genotyping of the identified isolates from human and meat sources by REP-PCR showed 100% similarity within the same cluster between human and meat isolates. All isolates were classified as MDR with an average multiple antibiotic resistance (MAR) index of 0.7. AgNPs-H2O2 at concentrations of 0.625, 1.25, 2.5 and 5 μg/mL showed complete bacterial growth inhibition.

CONCLUSIONS

Virulent MDR ESBL-producing E. coli were identified in retail meat products in Egypt, posing significant public health threats. Regular monitoring of ESBL-producing E. coli frequency and antimicrobial resistance profile in retail meat products is crucial to enhance their safety. AgNPs-H2O2 is a promising alternative for treating MDR ESBL-producing E. coli infections and reducing antimicrobial resistance risks.

Spatiotemporal dissemination of ESBL-producing Enterobacterales in municipal sewer systems: a prospective, longitudinal study in the city of Basel, Switzerland

Background

The contribution of community and hospital sources to the transmission of extended-spectrum β-lactamase producing Enterobacterales (ESBL-PE) remains elusive.

Aim

To investigate the extent of community dissemination and the contribution of hospitals to the spread of ESBL-PE by exploring their spatiotemporal distribution in municipal wastewater of the central European city of Basel.

Methods

Wastewater samples were collected monthly for two consecutive years throughout Basel, Switzerland, including 21 sites across 10 postcode areas of the city collecting either community wastewater (urban sites, n = 17) or community and hospital wastewater (mixed sites, n = 4). Presumptive ESBL-PE were recovered by selective culture methods. Standard methodologies were applied for species identification, ESBL-confirmation, and quantification.

Results

Ninety-five percent (477/504) of samples were positive for ESBL-PE. Among these isolates, Escherichia coli (85%, 1,140/1,334) and Klebsiella pneumoniae (11%, 153/1,334) were most common. They were recovered throughout the sampling period from all postcodes, with E. coli consistently predominating. The proportion of K. pneumoniae isolates was higher in wastewater samples from mixed sites as compared to samples from urban sites, while the proportion of E. coli was higher in samples from urban sites (p = 0.003). Higher numbers of colony forming units (CFUs) were recovered from mixed as compared to urban sites (median 3.2 × 10² vs. 1.6 × 10² CFU/mL). E. coli-counts showed moderate correlation with population size (rho = 0.44), while this correlation was weak for other ESBL-PE (rho = 0.21).

Conclusion

ESBL-PE are widely spread in municipal wastewater supporting that community sources are important reservoirs entertaining the spread of ESBL-PE. Hospital-influenced abundance of ESBL-PE appears to be species dependent.

Dissecting microbial communities and resistomes for interconnected humans, soil, and livestock

A debate is currently ongoing as to whether intensive livestock farms may constitute reservoirs of clinically relevant antimicrobial resistance (AMR), thus posing a threat to surrounding communities. Here, combining shotgun metagenome sequencing, machine learning (ML), and culture-based methods, we focused on a poultry farm and connected slaughterhouse in China, investigating the gut microbiome of livestock, workers and their households, and microbial communities in carcasses and soil. For both the microbiome and resistomes in this study, differences are observed across environments and hosts. However, at a finer scale, several similar clinically relevant antimicrobial resistance genes (ARGs) and similar associated mobile genetic elements were found in both human and broiler chicken samples. Next, we focused on Escherichia coli, an important indicator for the surveillance of AMR on the farm. Strains of E. coli were found intermixed between humans and chickens. We observed that several ARGs present in the chicken faecal resistome showed correlation to resistance/susceptibility profiles of E. coli isolates cultured from the same samples. Finally, by using environmental sensing these ARGs were found to be correlated to variations in environmental temperature and humidity. Our results show the importance of adopting a multi-domain and multi-scale approach when studying microbial communities and AMR in complex, interconnected environments.

Evaluation of Antimicrobial Resistance of Different Phylogroups of Escherichia coli Isolates from Feces of Breeding and Laying Hens

Animal and food sources are seen as a potential transmission pathway of multi-drug resistance (MDR) micro-organisms to humans. Escherichia. coli is frequently used as an indicator of fecal contamination in the food industry and known as a reservoir of antimicrobial resistance genes (ARGs). Microbial contamination as a major outcome for the poultry and egg industry and is a serious public health problem. In the present study we performed the quantification of β-glucoronidase positive E. coli in 60 fecal samples of breeding and laying hens collected in Portugal in 2019. Phylogenetic and pathotypic characterization, antimicrobial susceptibility, and detection of resistant extended-spectrum β-lactamase (ESBL) genes were assessed. The phylogenetic and pathogenic characterization and detection of ESBL genes were assessed by real-time PCR and antimicrobial susceptibility was evaluated using the disk diffusion method. Overall, E. coli quantification was 6.03 log CFU/g in breeding hens and 6.02 log CFU/g in laying hens. The most frequent phylogroups were B1. None of the isolates was classified as diarrheagenic E. coli (DEC). In total, 57% of the isolates showed MDR and 3.8% were positive for ESBL. Our study highlights that consumers may be exposed to MDR E. coli, presenting a major hazard to food safety and a risk to public health.

An Overview on Phenotypic and Genotypic Characterisation of Carbapenem-Resistant Enterobacterales

Improper use of antimicrobials has resulted in the emergence of antimicrobial resistance (AMR), including multi-drug resistance (MDR) among bacteria. Recently, a sudden increase in Carbapenem-resistant Enterobacterales (CRE) has been observed. This presents a substantial challenge in the treatment of CRE-infected individuals. Bacterial plasmids include the genes for carbapenem resistance, which can also spread to other bacteria to make them resistant. The incidence of CRE is rising significantly despite the efforts of health authorities, clinicians, and scientists. Many genotypic and phenotypic techniques are available to identify CRE. However, effective identification requires the integration of two or more methods. Whole genome sequencing (WGS), an advanced molecular approach, helps identify new strains of CRE and screening of the patient population; however, WGS is challenging to apply in clinical settings due to the complexity and high expense involved with this technique. The current review highlights the molecular mechanism of development of Carbapenem resistance, the epidemiology of CRE infections, spread of CRE, treatment options, and the phenotypic/genotypic characterisation of CRE. The potential of microorganisms to acquire resistance against Carbapenems remains high, which can lead to even more susceptible drugs such as colistin and polymyxins. Hence, the current study recommends running the antibiotic stewardship programs at an institutional level to control the use of antibiotics and to reduce the spread of CRE worldwide.

Disinfectant and heavy metal resistance profiles in extended spectrum β-lactamase (ESBL) producing Escherichia coli isolates from chicken meat samples

Biocidal compounds are frequently used as disinfectants in poultry industry and their widespread usage has risen concern due to the co-selection and persistence of antimicrobial resistance among bacteria. In this study, extended spectrum β-lactamase producing (ESBL) Escherichia coli isolates (n = 60) obtained from chicken meat were characterized by Pulsed Field Gel Electrophoresis (PFGE) and further tested for disinfectant and heavy metal resistance phenotypically and genotypically. Plasmid replicon types of these isolates were also determined. ESBL producing E. coli isolates were found to be resistant to ciprofloxacin (48.3 %) and gentamicin (15 %). The majority of these isolates (46.5 %) carried bla_CTX-M-55 gene. The isolates showed higher minimal inhibitory concentrations to cetylpyridinium chloride (90 %), cetyltrimethylammonium bromide (50 %), hexadecyltrimethylammonium bromide (46.7 %), triclosan (38.3 %), benzalkonium chloride (28.3 %), chlorhexidine (21.7 %), acriflavine (3.3 %), benzethonium chloride (1.7 %) and N-alkyl dimethyl benzyl ammonium chloride (1.7 %), but 18.3 % of the isolates were resistant to triclosan. Of the quaternary ammonium compounds (QACs) tolerance genes, mdfA, sugE(c), ydgE and ydgF were most present in all isolates, but the qacE, qacG, oqxA and oqxB genes were not detected. Of genes mediating the heavy metal resistance, the zitB gene was detected in all isolates, whereas the copA and cueO genes were detected in 96.67 % and 95 % of isolates, respectively. The IncFIB plasmid was commonly present (93.3 %) in ESBL producing E. coli isolates. Consequently, given the detection of genes mediating disinfectant and heavy metal resistance commonly in ESBL producing E. coli isolates as well as high rate of MICs against disinfectant compounds, the use of QACs for decontamination of the facilities may not be as effective as expected in poultry sector in Turkey.

Phylotypic Profiling, Distribution of Pathogenicity Island Markers, and Antimicrobial Susceptibility of Escherichia coli Isolated from Retail Chicken Meat and Humans

Escherichia coli (E.coli) found in retail chicken meat could be causing a wide range of infections in humans and constitute a potential risk. This study aimed to evaluate 60 E. coli isolates from retail chicken meat (n = 34) and human urinary tract infections (UTIs, n = 26) for phylogenetic diversity, presence of pathogenicity island (PAI) markers, antimicrobial susceptibility phenotypes, and antimicrobial resistance genes, and to evaluate their biofilm formation capacity. In that context, confirmed E.coli isolates were subjected to phylogrouping analysis using triplex PCR, antimicrobial susceptibility testing using the Kirby–Bauer disc diffusion method; PAI distribution was investigated by using two multiplex PCRs. Most of the chicken isolates (22/34, 64.7%) were identified as commensal E. coli (A and B1), while 12 isolates (35.3%) were classified as pathogenic virulent E. coli (B2 and D). Similarly, the commensal group dominated in human isolates. Overall, 23 PAIs were detected in the chicken isolates; among them, 39.1% (9/23) were assigned to group B1, 34.8% (8/23) to group A, 4.34% (1/23) to group B2, and 21.7% (5/23) to group D. However, 25 PAIs were identified from the human isolates. PAI IV536 was the most prevalent (55.9%, 69.2%) PAI detected in both sources. In total, 37 (61.7%) isolates of the chicken and human isolates were biofilm producers. Noticeably, 100% of E. coli isolates were resistant to penicillin and rifamycin. Markedly, all E. coli isolates displayed multiple antibiotic resistance (MAR) phenotypes, and the multiple antibiotic resistance index (MARI) among E. coli isolates ranged between 0.5 and 1. Several antibiotic resistance genes (ARGs) were identified by a PCR assay; the sul2 gene was the most prevalent (38/60, 63.3%) from both sources. Interestingly, a significant positive association (r = 0.31) between biofilm production and resistance to quinolones by the qnr gene was found by the correlation analysis. These findings were suggestive of the transmission of PAI markers and antibiotic resistance genes from poultry to humans or humans to humans through the food chain. To avoid the spread of virulent and multidrug-resistant E. coli, intensive surveillance of retail chicken meat markets is required.

The Effect of Infection Precautions on Extended-Spectrum Beta-Lactamase Enterobacteriaceae Colonization Among Nurses in Three Beirut Hospitals

Background and objective

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) are rapidly emerging worldwide. This study aimed to assess the effect of contact precaution (CP) on ESBL-PE-colonization rates among nurses in three hospitals in Beirut, Lebanon, where ESBL is endemic, in order to define the risk factors for colonization. Accordingly, the ongoing use of CP to prevent ESBL-PE transmission to healthy nurses was evaluated.

Methods

This cross-sectional study was conducted in three hospitals. Hospital 1 required CP, Hospital 2 had recently stopped CP, and Hospital 3 had stopped it three years previously. Questionnaires and stool-collection containers were distributed to all patient care nurses in those three hospitals. The Returned samples were tested using the agar dilution technique.

Results

A total of 269 out of 733 nurses volunteered to participate; 140 met the inclusion criteria (no recent hospitalization, antibiotic use, or known ESBL-PE colonization) and provided samples. Among them, 15% were ESBL-positive. Compared to nurses from Hospital 3, nurses from Hospital 1 were 59% less likely to be colonized, while nurses from Hospital 2 were 62% more likely to be colonized.

Conclusion

In hospitals where CP is in place for ESBL-positive patients, ESBL-PE prevalence in nursing staff was significantly lower. Additionally, a work experience of two to four years increased the odds of ESBL-PE colonization in comparison with longer nursing experience. CP may be a justifiable means of protection against ESBL-PE transmission to healthy nurses. The risk factors for colonization were discontinuation of CP and a shorter clinical work experience.

Escherichia coli Isolated from Organic Laying Hens Reveal a High Level of Antimicrobial Resistance despite No Antimicrobial Treatments

The present study investigated the resistance characteristics of E. coli isolates originating from 18 organic laying hen flocks. E. coli was isolated from different organs at three different time points, resulting in 209 E. coli isolates. The antibiotic susceptibility was determined by applying a microdilution assay. General, a high resistance rate was found. The antibiotic susceptibility was independent from the presence of pathological lesions, the isolation site, or the affiliation to a pathogenic serogroup. The majority of the isolates proved to be multi-drug-resistant (95.70%), of which 36.84% could be categorized as extensively drug-resistant. All isolates were resistant to oxacillin and tylosin. Resistance rates to amoxicillin (67.94%), cefoxitin (55.98%), ceftazidime (82.30%), colistin (73.68%), nalidixic acid (91.87%), streptomycin (42.58%), tetracycline (53.59%), and sulfamethoxazole (95.22%) were high. None of the isolates revealed pan-drug-resistance. A great heterogeneity of resistance profiles was found between isolates within a flock or from different organs of the same bird, even when isolates originated from the same organ. An increase in antimicrobial resistance was found to be correlated with the age of the birds. The fact, that no antibiotic treatment was applied except in two flocks, indicates that resistant bacteria circulating in the environment pose a threat to organic systems.

Genetic Characterization of Carbapenem-Resistant Klebsiella spp. from Municipal and Slaughterhouse Wastewater

Currently, human and veterinary medicine are threatened worldwide by an increasing resistance to carbapenems, particularly present in opportunistic Enterobacterales pathogens (e.g., Klebsiella spp.). However, there is a lack of comprehensive and comparable data on their occurrence in wastewater, as well as on the phenotypic and genotypic characteristics for various countries including Germany. Thus, this study aims to characterize carbapenem-resistant Klebsiella spp. isolated from municipal wastewater treatment plants (mWWTPs) and their receiving water bodies, as well as from wastewater and process waters from poultry and pig slaughterhouses. After isolation using selective media and determination of carbapenem (i.e., ertapenem) resistance using broth microdilution to apply epidemiological breakpoints, the selected isolates (n = 30) were subjected to WGS. The vast majority of the isolates (80.0%) originated from the mWWTPs and their receiving water bodies. In addition to ertapenem, Klebsiella spp. isolates exhibited resistance to meropenem (40.0%) and imipenem (16.7%), as well as to piperacillin-tazobactam (50.0%) and ceftolozan-tazobactam (50.0%). A high diversity of antibiotic-resistance genes (n = 68), in particular those encoding β-lactamases, was revealed. However, with the exception of bla_GES-5-like, no acquired carbapenemase-resistance genes were detected. Virulence factors such as siderophores (e.g., enterobactin) and fimbriae type 1 were present in almost all isolates. A wide genetic diversity was indicated by assigning 66.7% of the isolates to 12 different sequence types (STs), including clinically relevant ones (e.g., ST16, ST252, ST219, ST268, ST307, ST789, ST873, and ST2459). Our study provides information on the occurrence of carbapenem-resistant, ESBL-producing Klebsiella spp., which is of clinical importance in wastewater and surface water in Germany. These findings indicate their possible dissemination in the environment and the potential risk of colonization and/or infection of humans, livestock and wildlife associated with exposure to contaminated water sources.

Extended-Spectrum ß-Lactamase-Producing Escherichia coli in Conventional and Organic Pig Fattening Farms

Antimicrobial resistance is an increasing global problem and complicates successful treatments of bacterial infections in animals and humans. We conducted a longitudinal study in Mecklenburg-Western Pomerania to compare the occurrence of ESBL-producing Escherichia (E.) coli in three conventional and four organic pig farms. ESBL-positive E. coli, especially of the CTX-M type, were found in all fattening farms, confirming that antimicrobial resistance is widespread in pig fattening and affects both conventional and organic farms. The percentage of ESBL-positive pens was significantly higher on conventional (55.2%) than on organic farms (44.8%) with similar proportions of ESBL-positive pens on conventional farms (54.3–61.9%) and a wide variation (7.7–84.2%) on organic farms. Metadata suggest that the farms of origin, from which weaner pigs were purchased, had a major influence on the occurrence of ESBL-producing E. coli in the fattening farms. Resistance screening showed that the proportion of pens with multidrug-resistant E. coli was similar on conventional (28.6%) and organic (31.5%) farms. The study shows that ESBL-positive E. coli play a major role in pig production and that urgent action is needed to prevent their spread.

Prevalence and antimicrobial susceptibility of CTX-M-type-producing Escherichia coli from a wildlife zoo in China

Background

Wildlife zoos provide the opportunity for children and adults to interact with animals, However, it's unknown that the risk of contact with animals, which carried zoonotic pathogens and antimicrobial resistant bacteria.

Objectives

This study aimed to investigate the prevalence and antimicrobial susceptibility of extended‐spectrum β‐lactamases Escherichia coli (ESBLs‐EC) from a wildlife zoo in China.

Methods

A total of 93 wildlife faecal samples were collected from a wildlife zoo. Agar dilution method was used to determine the resistant phenotype. Whole genomes sequencing and bioinformatic analysis were employed to evaluate the molecular typing and genetic relationships of ESBLs‐EC.

Results

A total of 23 CTX‐M‐positive ESBLs‐EC were isolated from swan (n = 14), squirrel monkey (n = 5), black hat hanging monkey (n = 2), gibbon monkey (n = 1) and phoenicopteridae (n = 1) respectively. All ESBLs‐EC strains were resistant to cefotaxime, tetracycline, ciprofloxacin and trimethoprim‐sulfamethoxazole, but susceptible to colistin, tigecycline, meropenem and amikacin. By screening whole genome sequences, ESBLs‐EC strains main carried bla_CTX‐M‐55 (34.8%, 8/23) and bla_CTX‐M‐14 (26.0%, 6/23), following by bla_CTX‐M‐27 (21.7%, 5/23), bla_CTX‐M‐15 (13.0%, 3/23) and bla_{CTX‐M‐121} (4.3%, 1/23). ESBLs‐EC strains mainly belonged to phylogroup A (60.9%, 14/23), and ST48, ST746 and ST616 (3 strains respectively, 13.0%) were major ST types. Core genome‐based single nucleotide polymorphism (SNP) analysis suggested that strains from the swan, over the phylogenetic tree, have a closer genetic relationship with strains from other animals (black hat hanging monkey, gibbon monkey, phoenicopteridae and squirrel monkey).

Conclusions

CTX‐M type ESBLs‐EC can transmit between animals in wildlife zoos, which may be a risk of spread to animal keepers, veterinarians and visitors when contact with animals. Our study provides that the importance of hygiene measures to minimise the risk of transmission of ESBLs‐EC to visitors in wildlife zoos.

Multidrug-Resistant and Genetic Characterization of Extended-Spectrum Beta-Lactamase-Producing E. coli Recovered from Chickens and Humans in Egypt

Simple Summary

Feeding food chain animals with sub-therapeutic doses for prophylaxis or for growth-promoting purposes has led to the emergence of resistant bugs such as ESBL-E. coli. Infections caused by these superbugs are tremendously associated with treatment failures and high morbidity/mortality rates. Scarce information is currently available on the relation between the incidence of ESBL-E. coli in human and food chain animals in Egypt. The current study analyzed chicken and human fecal samples for isolation and characterization of ESBL-producing E. coli followed by sequencing the isolates. Significant similarities were detected between human and chicken isolates, indicating the possibility of zoonotic transmission. In conclusion, the study encouraged managing the use of antibiotics in veterinary field, to reduce the selection and spread of life-threating bugs to humans.

Abstract

Colonization of food chain animals such as chickens with extended-spectrum β-lactamases (ESBL) poses a major health threat to human. The current study aimed to determine the phenotypic and genotypic relationship between ESBL-producing E. coli from diseased human and chickens in Egypt. A total of 56 out of 120 chicken farms (46.7%) and 9 human samples (100%) were phenotypically and genotypically identified with at least one ESBL-phenotype/gene. Chicken isolates showed a high proportion of beta lactamase from CTX-M group 9 > TEM > PER families, followed by CTX-M group 1 > SHV > GES > OXA group10 > VEB > OXA group2 families, while human isolates only contained the CTX-M family. A high incidence of ESBL genes from the CTX-M family was recognized in both human and chicken isolates. Furthermore, nucleotide identity showed high similarity between chicken and human isolates. In conclusion, the current study traced phenotypes and genotypes of ESBL-producing E. coli from chickens and human samples in Egypt, reporting degrees of similarity that suggest potential zoonotic transmission. Our data highlighted the significant importance of chicken as a major food source not only in Egypt but all over the world in the spreading of ESBL-producing E. coli to human.

F Plasmid Lineages in Escherichia coli ST95: Implications for Host Range, Antibiotic Resistance, and Zoonoses

Escherichia coli sequence type 95 (ST95) is an extraintestinal pathogenic E. coli (ExPEC) renowned for its ability to cause significant morbidity and mortality in humans and poultry. A core genome analysis of 668 ST95 isolates generated 10 clades (A to J), 5 of which are reported here for the first time. F plasmid replicon sequence typing showed that almost a third (178/668 [27%]) of the collection carry pUTI89 (F29:B10) and were restricted to clade A and a sublineage of clade B. In contrast, almost half (328/668 [49%]) of the collection across multiple clades harbor ColV plasmids (multiple F types). Strikingly, ST95 lineages with pUTI89 were almost exclusively from humans, while ColV⁺ ST95 lineages were sourced from poultry and humans. Clade I was notable because it comprises temporally and geographically matched ColV⁺ isolates sourced from human and retail poultry meat, suggesting interspecies transmission via food. Clade F contained ST95 isolates of bovine origin, none of which carried ColV or pUTI89 plasmids. Remarkably, an analysis of a cohort of 34,176 E. coli isolates comprising 2,570 sequence types mirrored what was observed in ST95: (i) pUTI89 was overwhelmingly linked to E. coli sourced from humans but almost entirely absent from 13,027 E. coli isolates recovered from poultry, pigs, and cattle, and (ii) E. coli isolates harboring ColV plasmids were from multiple sources, including humans, poultry, and swine. Overall, our data suggest that F plasmids influence E. coli host range, clade structure, and zoonotic potential in ST95 and ExPEC more broadly.

IMPORTANCEE. coli ST95 is one of five dominant ExPEC lineages globally and noted for causing urinary tract and bloodstream infections and neonatal meningitis in humans and colibacillosis in poultry. Using high-resolution phylogenomics, we show that F replicon sequence type is linked to ST95 clade structure and zoonotic potential. Specifically, human centric ST95 clades overwhelmingly harbor F29:B10 (pUTI89) plasmids, while clades carrying both human- and poultry-sourced isolates are typically ColV⁺ with multiple replicon types. Importantly, several clades identified clonal ColV⁺ ST95 isolates from human and poultry sources, but clade I, which housed temporally and spatially matched isolates, provided the most robust evidence. Notably, patterns of association of F replicon types with E. coli host were mirrored within a diverse collection of 34,176 E. coli genomes. Our studies indicate that the role of food animals as a source of human ExPEC disease is complex and warrants further investigation.

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.

Bacteriophage-Mediated Modulation of Bacterial Competition during Selective Enrichment of Campylobacter

Selective media using antimicrobial supplements generate unique microbial ecology to facilitate bacterial isolation. However, antibiotic-resistant bacteria indigenous to samples can interfere with the isolation process using selective media. Recent studies showed that extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli is highly prevalent on retail raw chicken and compromises the efficacy of Campylobacter isolation because ESBL-producing E. coli are resistant to antimicrobial supplements in Campylobacter-selective media and outgrows Campylobacter. The objective of this study was to improve Campylobacter isolation by inhibiting the growth of ESBL-producing E. coli using bacteriophages (phages). The supplementation of Campylobacter-selective media with E. coli phages reduced the level of ESBL-producing E. coli during the enrichment step. When E. coli phages were combined with the antimicrobial supplements of Campylobacter-selective media, antimicrobial synergy was observed, particularly with rifampicin, an antibiotic used in Preston medium. Although the same materials (i.e., phages and selective media) were used, the sequence of combining the materials markedly influenced the inhibition of ESBL-producing E. coli and the isolation of Campylobacter. These findings indicated that the modulation of microbial competition at the enrichment step was critical to the successful isolation of fastidious bacteria and that phages can be utilized to facilitate the selective enrichment of target bacteria by inhibiting their competitive bacteria. IMPORTANCE Phages are promising antimicrobial alternatives. In this study, we first demonstrated that phages can be used to facilitate selective isolation of fastidious bacteria that are prone to be outgrown by bacterial competitors during isolation. The effectiveness of a phage-based isolation method was primarily dependent on the antimicrobial synergy between phages and antibiotics used in selective media. The same approach could be applied to the development of isolation methods for other fastidious bacteria.

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.

Genetic analysis of plasmid-encoded mcr-1 resistance in Enterobacteriaceae derived from poultry meat in the Netherlands

Background

Colistin is classified as the highest priority and critically important antimicrobial for human medicine by WHO as it is the last resort agent for treatment of carbapenem-resistant Enterobacteriaceae in humans. Additional research is necessary to elucidate the genetic structure of mcr-1 resistance genes, commonly found on plasmids, using WGS.

Objectives

To map and compare the genetic characteristics of 35 mcr-1-mediated colistin-resistant Enterobacteriaceae isolated from chicken meat to highlight the genetic variation of the mcr-1-containing plasmids.

Methods

Sequencing was performed using Illumina HiSeq2500, Novaseq6000 and ONT’s GridION. GridION data was locally basecalled and demultiplexed using ONT’s Albacore 2.3.4 followed by Porechop 2.3. Quality filtering was performed using Filtlong 2.0. Hybrid Assembly was performed using Unicycler 4.7. Plasmids were compared with reference sequences in plasmid-RefSeq and pATLAS.

Results

A total of 35 mcr-1 positive Enterobacteriaceae were investigated, which resulted in 34 qualitatively robust hybrid assemblies of 2 Klebsiella pneumoniae and 32 Escherichia coli. mcr-1.1 was present in 33/34 isolates. One isolate contained an mcr-1.1-like resistance gene, due to a deletion of one codon. Two mcr-1.1 genes were located on the chromosome, while the majority of the mcr-1 genes were found on IncX4 type plasmids (n = 19). Almost all plasmids identified in this study were highly similar to plasmids found in human-derived strains.

Conclusions

The mcr-1.1-containing plasmids from retail chicken show high sequence similarity to human mcr-1.1 plasmids, suggesting that this may be a contributor to the presence of colistin resistance in humans.

Molecular epidemiology of antibiotic-resistant genes and potent inhibitors against TEM, CTX-M-14, CTX-M-15, and SHV-1 proteins of Escherichia coli in district Peshawar, Pakistan

The Extended Spectrum Beta-Lactamases (ESBLs) producing bacteria is an issue of concern for clinicians resulting in minimize the treatment options. To overcome resistance mechanisms, novel inhibitors with good Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) properties must inhibit the ESBLs resistant genes. The current study aimed to identify the antibiotic resistance genes of ESBLs producing E. coli and a single inhibitor was designed to inhibit all the resistant proteins. The results showed that 42.9% ESBL producers had CTX-M (69.9%), TEM (63.4%), SHV (34.5%) and CTX-M-14 (17.5%) genes. The ESBLs producing isolates were resistant to cephalosporins, quinolones, and sulfonamide with Minimum Inhibitory Concentration (MICs) ranging from 64 to >256 μg/ml. To design multi inhibitory ligands, RECAP synthesis was used for the de-novo discovery of 1000 inhibitors database. Protein crystal structures were retrieved from Protein Data Base (PDB). Lipinski's rules of five were applied to the novel inhibitors database to improve the ADMET properties. The novel inhibitors database was selected for docking simulations. Placement of the ligand was used by the London dG algorithm implemented in Molecular Operating Environment (MOE), while GBVI/WSA dG algorithm was used for final refinement. Based on docking score, visual inspection of ligands interaction with key residues, binding affinity, and binding energy of ligands with proteins, ten compounds were selected for ESBLs proteins with best ADMET properties, binding energy, and binding affinity the reported ones. These hits compounds have unique scaffolds and are predicted to be a starting point for developing potent inhibitors against antibiotic-resistant proteins.

Protective Potential of an Autogenous Vaccine in an Aerogenous Model of Escherichia coli Infection in Broiler Breeders

In poultry, Escherichia coli is a common cause of high-cost infections. Consequently, autogenous vaccines are often used despite limited and conflicting evidence on their effectiveness have been presented. The present study aimed to investigate the efficacy of a commonly used autogenous vaccine, previously deemed ineffective, in an aerosol model of colibacillosis. Methods: Broiler breeders (n = 47) were randomly allocated to one of four groups (vaccinated and unvaccinated birds receiving an autogenous vaccine or sterile saline intramuscularly) and challenged with either aerosolised E. coli or vehicle at 29 weeks of age. Two days following inoculation, the birds were euthanised, thoroughly necropsied, and samples for bacteriology and histopathology were collected. Results: Vaccinated birds had a significantly lower bacteriology score compared to the unvaccinated group challenged with E. coli (p < 0.01) and a lower overall air sac lesion score (p < 0.05). Overall lung and spleen lesion scores only differed significantly between the unvaccinated E. coli challenged group compared to the vehicle inoculated groups. The overall gross pathology score was 2.8 and 1.95 in the unvaccinated and vaccinated E. coli challenge groups, respectively, whereas the vaccinated vehicle group had a score of 0.9 and the unvaccinated vehicle group a score of 1. Conclusions: A protective effect of an autogenous vaccine was found utilising an aerogenous model of colibacillosis through multiple methods of evaluation. The findings encourage the continued use of autogenous vaccines and underlines the necessity of discriminative experimental models with high predictive validity when evaluating vaccine interventions.

Inhibition of Antimicrobial-Resistant Escherichia coli Using a Broad Host Range Phage Cocktail Targeting Various Bacterial Phylogenetic Groups

Antimicrobial-resistant (AMR) commensal Escherichia coli is a major reservoir that disseminates antimicrobial resistance to humans through the consumption of contaminated foods, such as retail poultry products. This study aimed to control AMR E. coli on retail chicken using a broad host range phage cocktail. Five phages (JEP1, 4, 6, 7, and 8) were isolated and used to construct a phage cocktail after testing infectivity on 67 AMR E. coli strains isolated from retail chicken. Transmission electron microscopic analysis revealed that the five phages belong to the Myoviridae family. The phage genomes had various sizes ranging from 39 to 170 kb and did not possess any genes associated with antimicrobial resistance and virulence. Interestingly, each phage exhibited different levels of infection against AMR E. coli strains depending on the bacterial phylogenetic group. A phage cocktail consisting of the five phages was able to infect AMR E. coli in various phylogenetic groups and inhibited 91.0% (61/67) of AMR E. coli strains used in this study. Furthermore, the phage cocktail was effective in inhibiting E. coli on chicken at refrigeration temperatures. The treatment of artificially contaminated raw chicken skin with the phage cocktail rapidly reduced the viable counts of AMR E. coli by approximately 3 log units within 3 h, and the reduction was maintained throughout the experiment without developing resistance to phage infection. These results suggest that phages can be used as a biocontrol agent to inhibit AMR commensal E. coli on raw chicken.

"Occurrence of bla CTX-MGp1 and bla CTX-MGp26 in third generation cephalosporin-resistant and carbapenem- resistant bacterial isolates from southwest region of Saudi Arabia-a preliminary study"

This study was intended to identify the genes responsible for ESBL- and carbapenemase-producing bacterial isolates obtained from Jizan region. A hospital-based cross-sectional study was conducted over a period of 3 months (15th November 2018–15th February 2019). Fifty non-duplicate, 3rd-generation cephalosporin and carbapenem-resistant isolates were collected from microbiology lab of a tertiary care hospital in Jizan province and were screened for ESBLs and MBLs by phenotypic methods (CDT). The positive isolates (by phenotypic method) were then scanned for the presence of bla_ESBLs and bla_NDM-₁ genes, respectively, by PCR.

As a result, 10% isolates showed imipenem-cephalosporin co-resistance whereas 92% (46/50) of isolates were found to be ESBL producers by CDT. The maximum occurrence was observed for bla_CTX-M (70%), followed by bla_SHV (16%) and least occurrence was noted for bla_TEM (12%). Moreover, 97% isolates (34/35) were of bla_CTX-MGroup1 but one isolate showed the presence of bla_CTX-M Group26. Despite the co-resistance of cephalosporin and carbapenem, 14% (7/50) were found to be MBL producer on phenotypic detection by Combination Disc Test (CDT), whereas all the isolates were found to be negative for bla_NDM-1. Hence bla_CTX-MGroup1 is present in quite high fraction followed by bla_SHV in the bacterial isolates of Jizan region. Moreover, the occurrence of bla_CTX-M Group1 and bla_CTX-M Group26 in clinical isolates from the Jizan region of Saudi Arabia has been reported for the first time.

A One-Health Quantitative Model to Assess the Risk of Antibiotic Resistance Acquisition in Asian Populations: Impact of Exposure Through Food, Water, Livestock and Humans

Antimicrobial resistance (AMR) has become a major threat worldwide, especially in countries with inadequate sanitation and low antibiotic regulation. However, adequately prioritizing AMR interventions in such settings requires a quantification of the relative impacts of environmental, animal, and human sources in a One-Health perspective. Here, we propose a stochastic quantitative risk assessment model for the different components at interplay in AMR selection and spread. The model computes the incidence of AMR colonization in humans from five different sources: water or food consumption, contacts with livestock, and interhuman contacts in hospitals or the community, and combines these incidences into a per-year acquisition risk. Using data from the literature and Monte-Carlo simulations, we apply the model to hypothetical Asian-like settings, focusing on resistant bacteria that may cause infections in humans. In both scenarios A, illustrative of low-income countries, and B, illustrative of high-income countries, the overall individual risk of becoming colonized with resistant bacteria at least once per year is high. However, the average predicted incidence of colonization was lower in scenario B at 0.82 (CrI [0.13, 5.1]) acquisitions/person/year, versus 1.69 (CrI [0.66, 11.13]) acquisitions/person/year for scenario A. A high percentage of population with no access to improved water on premises and a high percentage of population involved in husbandry are shown to strongly increase the AMR acquisition risk. The One-Health AMR risk assessment framework we developed may prove useful to policymakers throughout Asia, as it can easily be parameterized to realistically reproduce conditions in a given country, provided data are available.

Populations of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae are different in human-polluted environment and food items: a multicentre European study

OBJECTIVES

To assess the extent to which food items are a source of extended-spectrum β-lactamase (ESBL) -producing Escherichia coli (ESBL-Ec) and ESBL-producing Klebsiella pneumoniae (ESBL-Kp) for humans in five European cities.

METHODS

We sampled 122 human polluted (hp)-environments (sewers and polluted rivers, as a proxy of human contamination) and 714 food items in Besançon (France), Geneva (Switzerland), Sevilla (Spain), Tübingen (Germany) and Utrecht (The Netherlands). A total of 254 ESBL-Ec and 39 ESBL-Kp isolates were cultured. All genomes were fully sequenced to compare their sequence types (ST) and core genomes, along with the distribution of bla_ESBL genes and their genetic supports (i.e. chromosome or plasmid).

RESULTS

Sequence data revealed that ESBL-Ec and ESBL-Kp isolates from hp-environments were genetically different from those contaminating food items. ESBL-Ec ST131 was widespread in the hp-environment (21.5% of the isolates) but absent from the food items tested. ESBL-Ec ST10 was in similar proportions in hp-environments and food items (15 and 10 isolates, respectively) but mostly carried reservoir-specific bla_ESBL. bla_CTX-M-1 and bla_SHV-12 predominated in food-related E. coli isolates (32% and 34% of the isolates, respectively), whereas bla_CTX-M-15 and bla_CTX-M-27 predominated in isolates from hp-environments (52% and 15% of the isolates, respectively).

CONCLUSIONS

We found a very limited connection between ESBL-Ec and ESBL-Kp populations retrieved in food items and from hp-environments and bla_ESBL. This suggests that human-to-human contamination, rather than the food chain, is possibly the most frequent route of ESBL-Ec and ESBL-Kp transmission in high-income countries.

Phage and phage lysins: New era of bio-preservatives and food safety agents

There has been an increase in the search and application of new antimicrobial agents as alternatives to use of chemical preservatives and antibiotic-like compounds by the food industry. The massive use of antibiotic has created a reservoir of antibiotic-resistant bacteria that find their way from farm to humans. Thus, there exists an imperative need to explore new antibacterial options and bacteriophages perfectly fit into the class of safe and potent antimicrobials. Phage bio-control has come a long way owing to advances with use of phage cocktails, recombinant phages, and phage lysins; however, there still exists unmet challenges that restrict the number of phage-based products reaching the market. Hence, further studies are required to explore for more efficient phage-based bio-control strategies that can become an integral part of food safety protocols. This review thus aims to highlight the recent developments made in the application of phages and phage enzymes covering pre-harvest as well as post-harvest usage. It further focuses on the major issues in both phage and phage lysin research hindering their optimum use while detailing out the advances made by researchers lately in this direction for full exploitation of phages and phage lysins in the food sector.

Antimicrobial Usage in Commercial and Domestic Poultry Farming in Two Communities in the Ashanti Region of Ghana

Poultry farming is a common practice in Ghana. Antibiotics are used, particularly in commercial poultry farming, as growth promoters and to prevent and cure infections. However, there is little information on antimicrobial usage in domestic poultry farming in Ghana. This study aimed to describe antimicrobial usage in commercial and domestic poultry farming. A cross-sectional survey was conducted within the Ashanti region of Ghana including 33 commercial farms and 130 households with domestic poultry farming. The median poultry population on commercial farms was 1500 (IQR: 300–3000) compared with 18 (IQR: 10–25) on domestic farms. The majority (97%, n = 32) of commercial farms used antimicrobials, compared with 43% (n = 56) of the domestic farms. Commercial farmers were 6.1 (CI: 3.2–11.8) times more likely to read and follow instructions on antimicrobials in comparison with domestic poultry keepers. About 11% of domestic and 34% of commercial farmers had received education on antimicrobial usage. None of the commercial farmers used herbal remedies; however, 40% (n/N = 52/130) of domestic farmers administered herbs. The misuse of antimicrobials in domestic poultry production calls for stricter regulations and training to limit the emergence and spread of antimicrobial-resistant bacteria among poultry.

Do vegetarians less frequently carry ESBL/pAmpC-producing Escherichia coli/Klebsiella pneumoniae compared with non-vegetarians?

BACKGROUND

ESBL and plasmid-mediated AmpC (pAmpC)-producing Enterobacteriaceae are frequently found on meat products in Dutch retail, especially on poultry.

OBJECTIVES

We investigated whether vegetarians are at lower risk of carrying ESBL/pAmpC-producing Escherichia coli/Klebsiella pneumoniae (ESBL-E/K) compared with persons who consume meat.

METHODS

Vegetarians, pescatarians (vegetarians who eat fish) and non-vegetarians (persons who eat meat at least three times per week) were asked to send in a faecal sample and a questionnaire. ESBL-E/K were cultured and MLSTs were determined. ESBL/pAmpC genes were analysed using PCR and sequencing. The risk of ESBL-E/K carriage in the three study groups was analysed using multivariable logistic regression.

RESULTS

Prevalence of ESBL-E/K carriage was 8.0% in vegetarians (63/785; 95% CI 6.3-10.1), 6.9% in pescatarians (27/392; 95% CI 4.8-9.8) and 3.8% in non-vegetarians (14/365; 95% CI 2.3-6.3). Multivariable analysis showed an OR for ESBL-E/K carriage of 2.2 for vegetarians (95% CI 1.2-4.0) and 1.6 for pescatarians (95% CI 0.8-3.2) compared with non-vegetarians. The predominant MLST was E. coli ST131 and the most common ESBL genes were blaCTX-M-15, blaCTX-M-27, blaCTX-M-14 and blaCTX-M-1 in all diet groups. Independent risk factors for ESBL-E/K carriage were travel to Africa/Latin America/Asia (OR 4.6; 95% CI 2.8-7.7) in the past 6 months and rarely/never washing hands before food preparation (OR 2.5; 95% CI 1.2-5.0).

CONCLUSIONS

Vegetarians and pescatarians did not have a lower risk of ESBL-E/K carriage compared with non-vegetarians, indicating that eating meat is not an important risk factor for ESBL-E/K carriage.

Comparative Analysis of Consumer Exposure to Resistant Bacteria through Chicken Meat Consumption in Germany

Human exposure to bacteria carrying antimicrobial resistance (AMR) genes through the consumption of food of animal origin is a topic which has gained increasing attention in recent years. Bacterial transmission can be enhanced, particularly in situations in which the consumer pays less attention to hygiene practices, and consumer exposure to foodborne resistant bacteria through ready-to-eat foods could be increased. It has been demonstrated that even methicillin-resistant Staphylococcus aureus (MRSA) bacteria, which have low prevalence and concentration in raw chicken meat in Germany, may reach the consumer during barbecue events after failures in hygiene practices. This study aimed to quantify the consumer exposure to extended-spectrum beta-lactamase- (ESBL) or ampicillinase class C (AmpC) beta-lactamase-producing E. coli in Germany through the consumption of chicken meat and bread during household barbecues. The study considered cross-contamination and recontamination processes from raw chicken meat by using a previously-developed probabilistic consumer exposure model. In addition, a comparative analysis of consumer exposure was carried out between ESBL-/AmpC-producing E. coli and MRSA. Our results demonstrated that the probability of ESBL-/AmpC-producing E. coli reaching the consumer was 1.85 × 10^-5 with the number of bacteria in the final serving averaging 332. Given the higher prevalence and concentration of ESBL-/AmpC-producing E. coli in raw chicken meat at retail compared to MRSA, comparative exposure assessment showed that the likelihood and extent of exposure were significantly higher for ESBL-/AmpC-producing E. coli than for MRSA. ESBL-/AmpC-producing E. coli was determined to be 7.6 times likelier (p-value < 0.01) than MRSA to reach the consumer, with five times the concentration of bacteria in the final serving (p-value < 0.01).

Emergence of Third Generation Cephalosporin Resistant Escherichia coli in Infants: Retrospective Study from a Tertiary Care Hospital in South India

Aim:

This study was aimed to evaluate the emergence of third generation cephalosporin resistant Escherichia coli isolated from the culture of various biological fluids of infants in a tertiary care hospital.

Background:

Resistance to commonly used antibiotics is consistently increasing during the last decades and it was found varying with time and geographical location.

Objectives:

To determine the prevalence of third generation cephalosporin sensitivity pattern of E. coli isolated from urine, stool, and throat swab culture from laboratory records.

Methods:

The retrospective study included the laboratory report of antibiotic sensitivity conducted on infants specimens during the period of 2 years. Third generation cephalosporin sensitivity patterns of E. coli isolated from urine, stool, and throat swab culture were collected and data were statistically analyzed.

Results:

Reports of 351 samples with positive E. coli were included in the study. More samples were analyzed from infants above 6 months of age with female dominance (184/351). Among the specimens tested, urine samples were highest 128/351 (35.0%). Cephalosporin resistant strain was found in 243/351 samples (69.2%) (p=0.0463) with 218/243 (89.7%) isolated from infants above 6 months of age and 25/243 (10.2%) were from infants below 6 months of age (p=0.038). The frequency of cephalosporin resistant E. coli in urine specimens of male and female infants was significant (p=0.0001).

Conclusion:

Third generation cephalosporin resistant E. coli strain was found in 69.2% of isolates and more in urine samples from female infants above 6 months of age. The clinicians should consider the emergence of cephalosporin resistant E. coli while selecting antibiotics as empirical treatment.

Population structure and uropathogenic potential of extended-spectrum cephalosporin-resistant Escherichia coli from retail chicken meat

Background

Food-producing animals and their products are considered a source for human acquisition of antimicrobial resistant (AMR) bacteria, and poultry are suggested to be a reservoir for Escherichia coli resistant to extended-spectrum cephalosporins (ESC), a group of antimicrobials used to treat community-onset urinary tract infections in humans. However, the zoonotic potential of ESC-resistant E. coli from poultry and their role as extraintestinal pathogens, including uropathogens, have been debated. The aim of this study was to characterize ESC-resistant E. coli isolated from domestically produced retail chicken meat regarding their population genetic structure, the presence of virulence-associated geno- and phenotypes as well as their carriage of antimicrobial resistance genes, in order to evaluate their uropathogenic potential.

Results

A collection of 141 ESC-resistant E. coli isolates from retail chicken in the Norwegian monitoring program for antimicrobial resistance in bacteria from food, feed and animals (NORM-VET) in 2012, 2014 and 2016 (n = 141) were whole genome sequenced and analyzed. The 141 isolates, all containing the beta-lactamase encoding gene bla_CMY-2, were genetically diverse, grouping into 19 different sequence types (STs), and temporal variations in the distribution of STs were observed. Generally, a limited number of virulence-associated genes were identified in the isolates. Eighteen isolates were selected for further analysis of uropathogen-associated virulence traits including expression of type 1 fimbriae, motility, ability to form biofilm, serum resistance, adhesion- and invasion of eukaryotic cells and colicin production. These isolates demonstrated a high diversity in virulence-associated phenotypes suggesting that the uropathogenicity of ESC-resistant E. coli from chicken meat is correspondingly highly variable. For some isolates, there was a discrepancy between the presence of virulence-associated genes and corresponding expected phenotype, suggesting that mutations or regulatory mechanisms could influence their pathogenic potential.

Conclusion

Our results indicate that the ESC-resistant E. coli from chicken meat have a low uropathogenic potential to humans, which is important knowledge for improvement of future risk assessments of AMR in the food chains.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02160-y.

Comparative genomics of ESBL-producing Escherichia coli (ESBL-Ec) reveals a similar distribution of the 10 most prevalent ESBL-Ec clones and ESBL genes among human community faecal and extra-intestinal infection isolates in the Netherlands (2014-17)

INTRODUCTION

The human gut microbiota is an important reservoir of ESBL-producing Escherichia coli (ESBL-Ec). Community surveillance studies of ESBL-Ec to monitor circulating clones and ESBL genes are logistically challenging and costly.

OBJECTIVES

To evaluate if isolates obtained in routine clinical practice can be used as an alternative to monitor the distribution of clones and ESBL genes circulating in the community.

METHODS

WGS was performed on 451 Dutch ESBL-Ec isolates (2014-17), including 162 community faeces and 289 urine and blood isolates. We compared proportions of 10 most frequently identified STs, PopPUNK-based sequence clusters (SCs) and ESBL gene subtypes and the degree of similarity using Czekanowski's proportional similarity index (PSI).

RESULTS

Nine out of 10 most prevalent STs and SCs and 8/10 most prevalent ESBL genes in clinical ESBL-Ec were also the most common types in community faeces. The proportions of ST131 (39% versus 23%) and SC131 (40% versus 25%) were higher in clinical isolates than in community faeces (P < 0.01). Within ST131, H30Rx (C2) subclade was more prevalent among clinical isolates (55% versus 26%, P < 0.01). The proportion of ESBL gene blaCTX-M-1 was lower in clinical isolates (5% versus 18%, P < 0.01). Czekanowski's PSI confirmed that the differences in ESBL-Ec from community faeces and clinical isolates were limited.

CONCLUSIONS

Distributions of the 10 most prevalent clones and ESBL genes from ESBL-Ec community gut colonization and extra-intestinal infection overlapped in majority, indicating that isolates from routine clinical practice could be used to monitor ESBL-Ec clones and ESBL genes in the community.

Old problems and new solutions: antibiotic alternatives in food animal production

The antimicrobial resistance crisis is a Global Health challenge that impacts humans, animals, and the environment alike. In response to increased demands for animal protein and by-products, there has been a substantial increase in the use of antimicrobial agents in the animal industry. Indeed, they are extensively used to prevent, control, and (or) treat disease in animals. In addition to infection control, in-feed supplementation with antimicrobials became common practice for growth promotion of livestock. Unfortunately, the global overuse of antimicrobials has contributed to the emergence and spread of resistance. As such, many countries have implemented policies and approaches to eliminate the use of antimicrobials as growth promoters in food animals, which necessitates the need for alternate and One Health strategies to maintain animal health and welfare. This review summarizes the antimicrobial resistance crisis from Global Health and One Health perspectives. In addition, we outline examples of potential alternate strategies to circumvent antimicrobial use in animal husbandry practices, including antivirulence agents, bacteriophages, and nutritional measures to control bacterial pathogens. Overall, these alternate strategies require further research and development efforts, including assessment of efficacy and the associated development, manufacturing, and labor costs.

The Impact of Modifying Empirical Antibiotic Therapy Based on Intestinal Colonization Status on Clinical Outcomes of Febrile Neutropenic Patients

Background

This paper aimed to inspect factors affecting febrile neutropenia patients with hematologic malignancies. The intestinal colonization rate of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) and carbapenem-resistant Enterobacteriaceae (CRE) was assessed. The rate of subsequent ESBL-E and CRE bacteremia correlated with corresponding bacterial colonization was evaluated. Further, the risk factors for ESBL-E and CRE intestinal colonization were examined. Finally, the impact of rectal swab screening combined with adapted empirical antibiotic therapy on the mortality rate of patients with febrile neutropenia was assessed.

Materials and Methods

Febrile neutropenia patients underwent rectal swabs and collection of blood culture specimens upon admission. Empirical treatment was subsequently modified according to rectal swab results if necessary. Bacteremia patients were treated according to blood culture results. Explorative forward-stepwise logistic regression analyses were used to identify risk factors for ESBL-E and CRE fecal carriage and mortality.

Results

In total, 201 rectal swabs and 402 blood samples were collected from 163 patients during 201 febrile neutropenia episodes. Of these episodes, 38 (18.90%) were colonized with ESBL-E and 30 (14.92%) with CRE. Bloodstream infections developed in 29/201 (14.42%) episodes. Only bacteremia episodes caused by Gram-negative bacilli were included in our analysis. The development of Gram-negative-rod bacteremia was observed in eight out of 38 (21.05%) ESBL-E colonized episodes and four out of 30 (13.33%) CRE-colonized episodes. A BSI developed in three out of 38 (7.89%) ESBL-E colonized episodes, and two out of 30 (6.66%) CRE-colonized episodes developed BSI with the respective organism. Multivariate analysis identified previous quinolone use as the only independent risk factor for fecal colonization of multi-drug-resistant (MDR) Enterobacteriaceae (ESBL-E and CRE) (odds ratio, 17.09; 95% confidence interval, 5.29 - 55.18; P <0.0001). No significant association was observed between ESBL-E and CRE carriage and increased risk of developing subsequent bacteremia. No significant differences were detected between groups receiving modified and non-modified treatments in duration of hospitalization or antibiotic therapy (univariate analysis) and 28-day mortality rate (logistic regression).

Conclusion

Quinolone exposure was a major risk factor for ESBL-E and CRE fecal carriage. Performing rectal swab screening for MDR Enterobacteriaceae and modifying empirical antibiotic therapy accordingly did not improve clinical outcomes of febrile neutropenia patients.

New strategies to prevent and control avian pathogenic Escherichia coli (APEC)

Avian pathogenic Escherichia coli (APEC) infections are associated with major economical losses and decreased animal welfare. In broiler production, APEC infections have traditionally been controlled by antibiotics, resulting in an increased prevalence of antibiotic-resistant E. coli. Concerns have been raised that transfer of antibiotic-resistant APEC via the food chain may result in risks for extra-intestinal infection of humans related to zoonotic transfer and increased difficulties in the treatment of human infections caused APEC-related E. coli types. In this review, the risks associated with APEC are presented based on new knowledge on transmission, virulence and antibiotic resistance of APEC. A major new change in our understanding of APEC is the high degree of genuine vertical transfer of APEC from parents to offspring. A new strategy for controlling APEC, including control of antibiotic-resistant APEC, has to focus on limiting vertical transfer from parents to offspring, and subsequent horizontal transmission within and between flocks and farms, by using all-in-all-out production systems and implementing a high level of biosecurity. Vaccination and the use of competitive exclusion are important tools to be considered. A specific reduction of antibiotic-resistant APEC can be obtained by implementing culling strategies, only allowing the use of antibiotics in cases where animal welfare is threatened. Strategies to reduce APEC, including antibiotic-resistant APEC, need to be implemented in the whole production pyramid, but it has to start at the very top of the production pyramid.

Molecular characterisation of extended-spectrum ß-lactamase producing Escherichia coli in wild birds and cattle, Ibadan, Nigeria

Background

Antimicrobial resistance (AMR) is an increasing global health concern reducing options for therapy of infections and also for perioperative prophylaxis. Many Enterobacteriaceae cannot be treated anymore with third generation cephalosporins (3GC) due to the production of certain 3GC hydrolysing enzymes (extended spectrum beta-lactamases, ESBLs). The role of animals as carriers and vectors of multi-resistant bacteria in different geographical regions is poorly understood. Therefore, we investigated the occurrence and molecular characteristics of ESBL-producing Escherichia coli (E. coli) in wild birds and slaughtered cattle in Ibadan, Nigeria.

Cattle faecal samples (n = 250) and wild bird pooled faecal samples (cattle egrets, Bubulcus ibis, n = 28; white-faced whistling duck, Dendrocygna viduata, n = 24) were collected and cultured on cefotaxime-eosin methylene blue agar. Antimicrobial susceptibility was determined by agar diffusion assays and all 3GC resistant isolates were genotypically characterised for AMR genes, virulence associated genes (VAGs) and serotypes using DNA microarray-based assays.

Results

All 3GC resistant isolates were E. coli: cattle (n = 53), egrets (n = 87) and whistling duck (n = 4); cultured from 32/250 (12.8%), 26/28 (92.9%), 2/24(8.3%), cattle, egrets and whistling duck faecal samples, respectively. blaCTX-M gene family was prevalent; blaCTX-M15 (83.3%) predominated over blaCTX-M9 (11.8%). All were susceptible to carbapenems. The majority of isolates were resistant to at least one of the other tested antimicrobials; multidrug resistance was highest in the isolates recovered from egrets.

The isolates harboured diverse repositories of other AMR genes (including strB and sul2), integrons (predominantly class 1) and VAGs. The isolates recovered from egrets harboured more AMR genes; eight were unique to these isolates including tetG, gepA, and floR. The prevalent VAGs included hemL and iss; while 14 (including sepA) were unique to certain animal isolates. E. coli serotypes O9:H9, O9:H30 and O9:H4 predominated. An identical phenotypic microarray profile was detected in three isolates from egrets and cattle, indicative of a clonal relationship amongst these isolates.

Conclusion

Wild birds and cattle harbour diverse ESBL-producing E. coli populations with potential of inter-species dissemination and virulence. Recommended guidelines to balance public health and habitat conservation should be implemented with continuous surveillance.

Prospective One Health genetic surveillance in Vietnam identifies distinct blaCTX-M-harbouring Escherichia coli in food-chain and human-derived samples

OBJECTIVES

We performed a One Health surveillance in Hanoi-a region with a high-density human population and livestock production, and a recognized hotspot of animal-associated antimicrobial resistance (AMR)-to study the contribution of bla_CTX-M-carrying Escherichia coli and plasmids from food-animal sources in causing human community-acquired urinary tract infections (CA-UTIs).

METHODS

During 2014-2015, 9090 samples were collected from CA-UTI patients (urine, n = 8564), pigs/chickens from farms and slaughterhouses (faeces, carcasses, n = 448), and from the slaughterhouse environment (surface swabs, water, n = 78). E. coli was identified in 2084 samples. Extended-spectrum β-lactamase (ESBL) production was confirmed in 235 and bla_CTX-M in 198 strains by PCR with short-read plasmid sequencing. Fourteen strains were long-read sequenced to enable plasmid reconstruction.

RESULTS

The majority of the ESBL-producing E. coli strains harboured bla_CTX-M (n = 198/235, 84%). High clonal diversity (48 sequence types, STs) and distinct, dominant STs in human sources (ST1193, n = 38/137; ST131, n = 30/137) and non-human sources (ST155, n = 25/61) indicated lack of clonal transmission between habitats. Eight bla_CTX-M variants were identified; five were present in at least two sample sources. Human and food-animal strains did not show similar plasmids carrying shared bla_CTX-M genes. However, IS6 elements flanking ISEcp1-bla_CTX-M-orf477/IS903B structures were common across habitats.

CONCLUSIONS

In this study, animal-associated bla_CTX-ME. coli strains or bla_CTX-M plasmids were not direct sources of CA-UTIs or ESBL resistance in humans, respectively, suggesting evolutionary bottlenecks to their adaptation to a new host species. Presence of common IS6 elements flanking bla_CTX-M variants in different plasmid backbones, however, highlighted the potential of these transposable elements for AMR transmission either within or across habitats.

Broiler Farms and Carcasses Are an Important Reservoir of Multi-Drug Resistant Escherichia coli in Ecuador

Antimicrobial resistance (AMR) is a major health threat for public and animal health in the twenty-first century. In Ecuador, antibiotics have been used by the poultry industry for decades resulting in the presence of multi-drug resistant (MDR) bacteria in the poultry meat production chain, with the consequent risk for public health. This study evaluated the prevalence of ESBL/AmpC and mcr genes in third-generation cephalosporin-resistant Escherichia coli (3GC-R E. coli) isolated from broiler farms (animal component), broiler carcasses (food component), and human enteritis (human component) in Quito-Ecuador. Samples were collected weekly from November 2017 to November 2018. For the animal, food, and human components, 133, 335, and 302 samples were analyzed, respectively. Profiles of antimicrobial resistance were analyzed by an automated microdilution system. Resistance genes were studied by PCR and Sanger sequencing. From all samples, 122 (91.7%), 258 (77%), and 146 (48.3%) samples were positive for 3GC-R E. coli in the animal, food, and human components, respectively. Most of the isolates (472/526, 89.7%) presented MDR phenotypes. The ESBL bla_CTX-M-55, bla_CTX-M-3, bla_CTX-M-15, bla_CTX-M-65, bla_CTX-M-27, and bla_CTX-M-14 were the most prevalent ESBL genes while bla_CMY-2 was the only AmpC detected gene. The mcr-1 gene was found in 20 (16.4%), 26 (10.1%), and 3 (2.1%) of isolates from animal, food, and human components, respectively. The implication of poultry products in the prevalence of ESBL/AmpC and mcr genes in 3GC-R must be considered in the surveillance of antimicrobial resistance.

The Continuing Plague of Extended-Spectrum β-Lactamase Producing Enterbacterales Infections: An Update

Antimicrobial resistance is a common iatrogenic complication of modern life and medical care. One of the most demonstrative examples is the exponential increase in the incidence of extended-spectrum β-lactamases (ESBLs) production among Enterobacteriaceae, that is, the most common human pathogens outside of the hospital setting. Infections resulting from ESBL-producing bacteria are associated with devastating outcomes, now affecting even previously healthy individuals. This poses an enormous burden and threat to public health. This article aims to narrate the evolving epidemiology of ESBL infections and highlights current challenges in terms of management and prevention of these common infections.

What can we learn from previous pandemics to reduce the frequency of emerging infectious diseases like COVID-19?

The global risks report of 2020 stated, climate-related issues dominate all of the top-five long-term critical global risks burning the planet and according to the report, "as existing health risks resurge and new ones emerge, humanity's past successes in overcoming health challenges are no guarantee of future results." Over the last few decades, the world has experienced several pandemic outbreaks of various pathogens and the frequency of the emergence of novel strains of infectious organisms has increased in recent decades. As per expert opinion, rapidly mutating viruses, emergence and re-emergence of epidemics with increasing frequencies, climate-sensitive vector-borne diseases are likely to be increasing over the years and the trends will continue and intensify. Susceptible disease hosts, anthropogenic activities and environmental changes contribute and trigger the 'adaptive evolution' of infectious agents to thrive and spread into different ecological niches and to adapt to new hosts. The overarching objective of this paper is to provide insight into the human actions which should be strictly regulated to help to sustain life on earth. To identify and categorize the triggering factors that contribute to disease ecology, especially repeated emergence of disease pandemics, a theory building approach, 'Total Interpretive Structural Modeling' (TISM) was used; also the tool, 'Impact Matrix Cross-Reference Multiplication Applied to a Classification' analysis (MICMAC) was applied to rank the risk factors based on their impacts on other factors and on the interdependence among them. This mathematical modeling tool clearly explains the strength, position and interconnectedness of each anthropogenic factor that contributes to the evolution of pathogens and to the frequent emergence of pandemics which needs to be addressed with immediate priority. As we are least prepared for another pandemic outbreak, significant policy attention must be focused on the causative factors to limit emerging outbreaks like COVID 19 in the future.

Antibiotic Resistance: Moving From Individual Health Norms to Social Norms in One Health and Global Health

Antibiotic resistance is a problem for human health, and consequently, its study had been traditionally focused toward its impact for the success of treating human infections in individual patients (individual health). Nevertheless, antibiotic-resistant bacteria and antibiotic resistance genes are not confined only to the infected patients. It is now generally accepted that the problem goes beyond humans, hospitals, or long-term facility settings and that it should be considered simultaneously in human-connected animals, farms, food, water, and natural ecosystems. In this regard, the health of humans, animals, and local antibiotic-resistance-polluted environments should influence the health of the whole interconnected local ecosystem (One Health). In addition, antibiotic resistance is also a global problem; any resistant microorganism (and its antibiotic resistance genes) could be distributed worldwide. Consequently, antibiotic resistance is a pandemic that requires Global Health solutions. Social norms, imposing individual and group behavior that favor global human health and in accordance with the increasingly collective awareness of the lack of human alienation from nature, will positively influence these solutions. In this regard, the problem of antibiotic resistance should be understood within the framework of socioeconomic and ecological efforts to ensure the sustainability of human development and the associated human-natural ecosystem interactions.

Mobility of β-Lactam Resistance Under Bacterial Co-infection and Ampicillin Treatment in a Mouse Model

Ingestion of food- or waterborne antibiotic-resistant bacteria may lead to the dissemination of antibiotic-resistance genes in the gut microbiota and the development of antibiotic-resistant bacterial infection, a significant threat to animal and public health. Food or water may be contaminated with multiple resistant bacteria, but animal models on gene transfer were mainly based on single-strain infections. In this study, we investigated the mobility of β-lactam resistance following infection with single- versus multi-strain of resistant bacteria under ampicillin treatment. We characterized three bacterial strains isolated from food-animal production systems, Escherichia coli O80:H26 and Salmonella enterica serovars Bredeney and Heidelberg. Each strain carries at least one conjugative plasmid that encodes a β-lactamase. We orally infected mice with each or all three bacterial strain(s) in the presence or absence of ampicillin treatment. We assessed plasmid transfer from the three donor bacteria to an introduced E. coli CV601gfp recipient in the mouse gut, and evaluated the impacts of the bacterial infection on gut microbiota and gut health. In the absence of ampicillin treatment, none of the donor or recipient bacteria established in the normal gut microbiota and plasmid transfer was not detected. In contrast, the ampicillin treatment disrupted the gut microbiota and enabled S. Bredeney and Heidelberg to colonize and transfer their plasmids to the E. coli CV601gfp recipient. E. coli O80:H26 on its own failed to colonize the mouse gut. However, during co-infection with the two Salmonella strains, E. coli O80:H26 colonized and transferred its plasmid to the E. coli CV601gfp recipient and a residential E. coli O2:H6 strain. The co-infection significantly increased plasmid transfer frequency, enhanced Proteobacteria expansion and resulted in inflammation in the mouse gut. Our findings suggest that single-strain infection models for evaluating in vivo gene transfer may underrepresent the consequences of multi-strain infections following the consumption of heavily contaminated food or water.

Efficacy of a competitive exclusion culture against extended-spectrum β-lactamase-producing Escherichia coli strains in broilers using a seeder bird model

Background

Administration of a competitive exclusion culture (CE culture) has the potential to induce protective effects in very young chicks against caecal colonisation by EEC (= extended-spectrum β-lactamases [ESBL] and AmpC-type [AmpC] beta-lactamases producing Escherichia coli). The study aimed to verify the protective capacity of a CE culture in broilers using the seeder bird model against EEC exposure of the chicks.

Results

Introduction of infected seeder birds resulted in rapid and strong caecal colonisation of four different EEC challenge strains tested in untreated contact broilers. Compared to controls the broilers pre-treated with the CE culture showed a considerable decrease in caecal load of different EEC challenge strains from about 3.0–3.5 log₁₀ units (P < 0.05) on day 9 of life to 2.5–3.0 log₁₀ units (P < 0.05) on day 37. A slightly higher protective level of the CE culture in layer birds than in broilers raises the question on reasons for possible differences in the efficacy of CE culture in broiler and layer breeds. Whether the diet’s protein content has an impact on both normal intestinal flora composition and the efficacy of CE cultures against EEC or other pathogens remains open and needs further elucidation.

Conclusions

Our findings suggest that CE cultures of undefined composition can be valuable to reduce the intestinal colonisation by EEC in newly hatched broilers.