Search

Extended‑spectrum β‑lactamase (ESBL) genes are responsible for creating Multidrug‑resistant and Extensive drug resistance (XDR) patterns in Acinetobacter baumanii isolates, so limit treatment options and increase mortality and morbidity. This study aimed to development of a multiplex PCR assay for the detection of extended-spectrum beta-lactamase genes including blaCTX-M, blaSHV and blaTEM among clinical samples of Acinetobacter baumanii isolates in Tehran, Iran. In present study, 100 clinical Acinetobacter baumannii strains have been gathered from patients in Motahhari hospital in Tehran city, Iran. Antibiotic susceptibility test was conducted by Kirby–Bauer disc diffusion method. To identify ESBL-producing strains, used combined disk test and Multiplex PCR method was used for Simultaneous diagnosis of blaCTX-M, blaSHV, and blaTEM genes. Out of 100 isolates, 93% were ESBL-positive according to the phenotypic test. Most of the isolates were XDR and the highest sensitivity was for colistin. The frequency of bla CTX-M, blaSHV and blaTEM genes was 95, 1, and 2% respectively. The high percentage of antibiotic resistance and high prevalence of the blaCTX-M gene in A. baumannii isolates is a serious threat to the effectiveness of available antibiotics. This study showed Multiplex PCR can be a reliable and sensitive technique for the fast detection of ESBL genes in Acinetobacter baumannii isolates. [ABSTRACT FROM AUTHOR]

Background: Escherichia coli (E. coli) strains harbor various allelic versions of beta lactamase genes and their identification using conventional phenotypic tests is a tedious and time consuming task. In the present study, multiplex PCR is performed for the simulatanoues detection of E. coli phylogroups and extended-spectrum β-lactamase-(ESBL) genes. Methods: A total of 128 E. coli isolates from urine samples were screened for antibiotic resistance and expression of ESBL activity using phenotypic and genotypic methods. Uniplex and multiplex PCRs were used to detect E. coli phylogroup detrminants and blaCTX-M-15, blaOXA-1 and TEM1 genes. Chi Square test of independence was employed for evaluating significant levels at P value < 0.05. Results: Phylogroup B2 was detected as the predominant group (36%) followed by group D (30%), A (25%) and B1 (9%). The highest resistance was seen against nalidixic acid (100%) and the lowest against amoxicillinclavulanic acid (55%). Significant P values were observed for resistance against cefotaxime and cefepime in the phylogroup B2 while resistance against cefoxitin, sulfamethoxazole and fosfomycin was significantly associated with group D. Combination disc diffusion test (CDDT) showed ESBL activity in 42% E. coli isolates. A significant association of blaCTX-M-15 gene was observed for phylogroup B2 (P = 0.007). Moreover, a combination genotype of blaCTX-M-15 and TEM1 was also found statistically prevalent in phylogroup B2 (P = 0.006). Conclusion: The study highlights the alarming rise in antibiotic resistance and delineates B2 a predominant phylogoup with a high prevalence of blaCTX-M-15 and TEM1 genes in urinary E. coli isolates. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance is a major public health concern worldwide. This study aims to determine the prevalence of Enterobacterales producing beta-lactamase (TEM, SHV, OXA) or extended-spectrum beta-lactamases (ESBL), as well as plasmid-mediated resistance to quinolones (PMQR) (qnrA, qnrB, qnrS) in companion animals from the northeast region of Romania. A total of 124 faecal samples were collected aseptically from healthy dogs attending the veterinary practice for vaccination and cultivated on Brilliance ESBL medium (Oxoid, UK). The ESBL production testing was performed using the combination disc test. The identification of Enterobacterales strains was achieved using molecular identification and based on biochemical tests. Antimicrobial susceptibility testing was performed using the disk diffusion method. Identification of genes encoding for beta-lactamase enzymes and genes encoding plasmid-mediated resistance to quinolones was performed by PCR according to the protocols previously described. After ESBL screening, 31 (31/124; 25%) extended-spectrum cephalosporin (ESC)-resistant Enterobacterales were obtained, and 67.74% (21/31) of them were confirmed as ESBL-producers. Regarding the Enterobacterales species, 27 (27/31; 87.1%) were Escherichia coli, and 4 (4/31; 12.9%) strains were Klebsiella pneumoniae. Among the ESBL-producing isolates, the blaCTX-M-1 gene group was predominant (58.82%), followed by the blaCTX-M-9 group (41.18%). The blaTEM, blaSHV and blaOXA gene groups were identified in 54.83%, 29.03% and 3.22% of the analysed strains, respectively. The prevalence of PMQR genes was 22.58% and consisted only of qnrS (19.35%) and qnrA (3.22%) genes. The prevalence of ESBL strains related to the total number of analysed samples was 16.93% (21/124). The findings show a significant prevalence of ESBLs and PMQR genes in Enterobacterales strains isolated from the faeces of healthy dogs, implying that pets may pose a risk of transmitting ESBL strains to other animals or owners.

Antimicrobial resistance is a major public health concern worldwide. This study aims to determine the prevalence of Enterobacterales producing beta-lactamase (TEM, SHV, OXA) or extended-spectrum beta-lactamases (ESBL), as well as plasmid-mediated resistance to quinolones (PMQR) (qnrA, qnrB, qnrS) in companion animals from the northeast region of Romania. A total of 124 faecal samples were collected aseptically from healthy dogs attending the veterinary practice for vaccination and cultivated on Brilliance ESBL medium (Oxoid, UK). The ESBL production testing was performed using the combination disc test. The identification of Enterobacterales strains was achieved using molecular identification and based on biochemical tests. Antimicrobial susceptibility testing was performed using the disk diffusion method. Identification of genes encoding for beta-lactamase enzymes and genes encoding plasmid-mediated resistance to quinolones was performed by PCR according to the protocols previously described. After ESBL screening, 31 (31/124; 25%) extended-spectrum cephalosporin (ESC)-resistant Enterobacterales were obtained, and 67.74% (21/31) of them were confirmed as ESBL-producers. Regarding the Enterobacterales species, 27 (27/31; 87.1%) were Escherichia coli and 4 (4/31; 12.9%) strains were Klebsiella pneumoniae. Among the ESBL-producing isolates, the blaCTX-M-1 gene group was predominant (58.82%), followed by the blaCTX-M-9 group (41.18%). The blaTEM, blaSHV and blaOXA gene groups were identified in 54.83%, 29.03% and 3.22% of the analysed strains, respectively. The prevalence of PMQR genes was 22.58% and consisted only of qnrS (19.35%) and qnrA (3.22%) genes. The prevalence of ESBL strains related to the total number of analysed samples was 16.93% (21/124). The findings show a significant prevalence of ESBLs and PMQR genes in Enterobacterales strains isolated from the faeces of healthy dogs, implying that pets may pose a risk of transmitting ESBL strains to other animals or owners. [ABSTRACT FROM AUTHOR]

Simple Summary: Salmonella is an important pathogen, which causes a variety of animal salmonellosis and foodborne diseases in humans. In recent years, due to the abuse of antimicrobials, the rapid emergence of resistant Salmonella, especially extended spectrum β-lactamase-positive strains (ESBL-producers), has brought great challenges to animal industries and public health safety. The pathogenicity of Salmonella depends on a variety of virulence factors coded by genes in chromosomal pathogenicity islands (SPI) and plasmids. The antibiotic resistance and pathogenic potential of Salmonella have been studied extensively. However, there are gaps that still exist in our understanding of the relationship between resistance and virulence. In this study, we collected 117 Salmonella isolates from diseased chickens in Sichuan Province of China from 2019 to 2021, and investigated antimicrobial resistance (AMR) patterns, including extended spectrum β-lactamase (ESBL) resistance, the prevalence and con-translation of ESBL and virulence genes, and sequence type (ST) among these isolates. The Salmonella isolates showed different frequencies of resistance to antimicrobials, 41.03% of which were ESBL-producers. ESBL genes, such as blaCTX-M-55 (63.29%), blaOXA-31 (26.58%), blaCTX-M-65 (20.25%), and blaTEM-1 (18.99%), were detected. Moreover, the 117 isolates had 11 virulence genes, with frequencies ranging from 29.06% to 100%. There were associations between resistance to cephalosporins and the ESBL genes. The blaCTX-M-55 showed the largest effect on the resistance and there was also a significant association between the presence of most virulence genes and ESBL genes. All isolates were divided into 11 types. The co-transfer of ESBL and virulence genes was observed in the plasmid conjugation test. From this study, we can conclude that Salmonella isolates from chicken were common carriers of ESBLs and multiple virulence genes, and the horizontal transfer played a key role in the dissemination of antimicrobial resistance and pathogenesis. Importantly, the interaction of resistance and virulence factors reinforces the marked pathogenic potential of Salmonella. The aim of this study was to explore the association between antimicrobial resistance, ESBL genes, and virulence genes of Salmonella isolates. From 2019 to 2021, a total of 117 Salmonella isolates were obtained from symptomatic chickens in Sichuan Province, China. The strains were tested for antimicrobial resistance and the presence of ESBL according to the Clinical and Laboratory Standards Institute (CLSI) instructions. The presence of ESBL genes and genes for virulence was determined using Polymerase Chain Reaction (PCR). In addition, Multilocus Sequence Typing (MLST) was applied to confirm the molecular genotyping. Moreover, the mechanism of ESBL and virulence gene transfer and the relationships between the resistance phenotype, ESBL genes, and virulence genes were explored. The isolates exhibited different frequencies of resistance to antibiotics (resistance rates ranged from 21.37% to 97.44%), whereas 68.38% and 41.03% of isolates were multi-drug resistance (MDR) and ESBL-producers, respectively. In the PCR analysis, blaCTX-M was the most prevalent ESBL genotype (73.42%, 58/79), and blaCTX-M-55 showed the most significant effect on the resistance to cephalosporins as tested by logistic regression analysis. Isolates showed a high carriage rate of invA, avrA, sopB, sopE, ssaQ, spvR, spvB, spvC, stn, and bcfC (ranged from 51.28% to 100%). MLST analysis revealed that the 117 isolates were divided into 11 types, mainly ST92, ST11, and ST3717. Of 48 ESBL-producers, 21 transconjugants were successfully obtained by conjugation. Furthermore, ESBL and spv virulence genes were obtained simultaneously in 15 transconjugants. These results highlighted that Salmonella isolates were common carriers of ESBLs and multiple virulence genes. Horizontal transfer played a key role in disseminating antimicrobial resistance and pathogenesis. Therefore, it is necessary to continuously monitor the use of antimicrobials and the prevalence of AMR and virulence in Salmonella from food animals and to improve the antibiotic stewardship for salmonellosis. [ABSTRACT FROM AUTHOR]

This study determined the antimicrobial resistance profiles and molecularly characterized beta-lactam- and fluoroquinolone-resistant E. coli recovered from human clinical samples. Three hundred (300) clinical samples collected from two major tertiary healthcare institutions were analyzed using standard microbiological techniques. Antimicrobial susceptibility testing and phenotypic detection of extended-spectrum beta-lactamase (ESBL) were done by disc diffusion and Double Disk Synergy Test. Molecular characterization for ESBL and fluoroquinolone-resistant genes were done by PCR with specific primers. In total, 44 (14.7%) ESBL-producing E. coli were recovered from human clinical specimens. The recovered isolates were multidrug-resistant with multiple antibiotics resistance index values ranging from 0.5–0.8. Isolates exhibited resistance to sulfamethoxazole/trimethoprim 44 (100%), cefoxitin 42 (95.5%), tetracycline 42 (95.5 %), cefuroxime 41 (93.2%), ciprofloxacin 40 (90.9%), cefotaxime 37 (84.1%), amoxicillin 37 (84.1%), amoxicillin/clavulanic acid 37 (84.1), and ceftazidime 35 (79.5%). BlaTEM 41 (93.2%) ESBL gene was the most predominant gene among the isolates, followed by blaCTX-M 9 (20.5%), and blaSHV 1 (2.3%) genes. Co-existence of blaTEM +blaSHV, blaTEM + blaCTX-M, and blaTEM +blaSHV + blaCTX-M genes was observed in 1 (2.3%), 7 (15.9%), and 4 (9.1%) isolates, respectively. All the fluoroquinolone-resistant isolates harbored aac-lb-6-cr gene while Qnr gene was absent. Association of fluoroquinolone resistance- and β-lactam resistance genes; aac-lb-6-cr + blaTEM + blaSHV + blaCTM was observed in 5 (11.4%) isolates. Our study showed high frequency of ESBL-producing E. coli harboring ESBL and fluoroquinolone resistance genes from human clinical samples in Ebonyi State, Nigeria. The high frequency of multidrug-resistant E. coli in our study is very worrisome and could have significant public health impact such as treatment failures, and possibly death, if not properly managed. It is therefore imperative to establish strong regulative measures and guidelines that would help in curtailing the increasing dissemination of these superbugs in healthcare institutions in Nigeria.

Proteus mirabilishas the ability to infiltrate and colonize woundscausing wound infections in both community and hospitalized patients. Due to the production of extended-spectrum-lactamases, P. mirabilis has developed resistance to beta-lactam antibioticsas a result of conventional use of antibioticslimitingtreatment options for clinicians.The current study is aimed to determine the phylogenic analysis and molecular characterization of antibiotic resistant genes of P. mirabilisrecovered from infected patients of skin and soft tissue wounds.A total of 800wound samples were obtained from infected wound patientsat Khyber Teaching Hospital (KTH) and Hayatabad Medical Complex (HMC),Peshawar.The collected samples were identified phenotypically using API 20E strips and antibiogram was determined using standard procedures. Molecular identification was done through sequencing of 16sRNA and phylogenetic analysis was performed using Molecular Evolutionary Genetics Analysis (MEGA-7) software. The antibiotic resistant genes of P. mirabilis were detected by PCR using specific primers.Out of 800 samples,84 isolatesyielded the growth ofP. mirabilis.Phylogenetic tree revealed that 100% of samples No. A-1 and No. A-2 are closely related to P. mirabilis to NR 043997.1:1-1503 P. mirabilis strain NCTC 11938 and 99%to (NR 114419.1:1-1495 P. mirabilis strain ATCC 29906).The results of antibiogram revealed that most of the isolates were resistant against antibiotics; cephalosporins, ampicillin, quinolones, chloramphenicol and aminoglycosides while showed good results against MEM, TZP and SCF.Of the isolates, 72.6% were found positive for ESBLs production. Molecular analysis showed that 40%of isolates were positive for blaTEM, blaCTX-M 14 (20%) and blaCTX-M (5%).The current study showed that the prevalence of blaTEM, blaCTX-M and blaCTX-M-14 genes carrying P. mirabilis in a tertiary care hospital Peshawar Pakistan. Phylogenetic analysis shows that sequences are closely related with the reference sequences ofP. Mirabilisamong infected patients of skin and soft tissue woundsand is resistant to the commercially available antibioticsresulting in a therapeutic challenge for clinicians. [ABSTRACT FROM AUTHOR]

Abstract Background Antimicrobial resistance (AMR) in bacterial pathogens is a worldwide concern that demands immediate attention. Most information on AMR originates from high-income countries and little is known about the burden in Africa, particularly Nigeria. Using four sentinel sites (General hospitals) in Lagos State, this study sought to estimate the burden of AMR. Methods This is a hospital-based surveillance using secondary health care centres. Four sites were randomly selected and included in the study. Clinical isolates were collected over a period of 6 months for each site from August 2020 to March 2021. All isolates were characterised and analysed for resistance to 15 antibiotics using the Kirby-Baur method. Multiplex PCR assay was used for the detection of Extended spectrum beta lactamase genes. Data analysis was done using SPSS version 27.0. Results Four hundred and ninety-nine (499) patients consented and participated in this study, consisting of 412 (82.6%) females and 87 (17.4%) males. The mean age ± SD of the participants was 33.9 ± 13.8 with a range of 1–89 years. The majority (90.8%) of the participants were outpatients. Two hundred and thirty-two (232) isolates were obtained from 219 samples, comprising of 120 (51.7%) Gram positive and 112 (48.3%) Gram negative organisms. Key bacterial pathogens isolated from this study included Staphylococcus aureus (22.8%), Escherichia coli (16.4%), Staphylococcus spp. (15.9%), Enterococcus spp. (7.3%) and Klebsiella pneumoniae (6.5%). There was high prevalence of multi-drug resistance (79.3%) among the isolates with 73.6% of Staphylococcus aureus phenotypically resistant to methicillin and 70% possessed the MecA gene. 76.5% of Enterococcus spp. isolated were Vancomycin resistant. Overall, resistance to Cephalosporins was most frequently/commonly observed (Cefotaxime 87.5%). Conclusion A high incidence of AMR was identified in clinical bacteria isolates from selected general hospitals in Lagos State, highlighting the necessity for the implementation of national action plans to limit the prevalence of AMR. Surveillance via collection of isolates has a lot of promise, especially in resource-limited environments.

Background: Antimicrobial resistance (AMR) is an emerging threat to global health security. Globally, an estimated 700,000 deaths are attributed to AMR annually. Annual deaths due to AMR are projected to reach 10 million by 2050 if current trends persist. Extended Spectrum P-Lactamases (ESBLs) have the ability to hydrolyse penicillins, cephalosporins up to the third generation, and monobactams, but not P-lactamase inhibitors such as clavulanic acid. ESBLs undergo continuous mutation, leading to the development of new enzymes with over 400 different ESBL variants described. This study aimed to detect selected CTX-M genes, SHV, and TEM genes in Extended Spectrum Beta-Lactamase producing Klebsiella pneumoniae and Pseudomonas aeruginosa in Jos, Nigeria. Methodology: A total of 110, non-replicated isolates of Klebsiella pneumonia and 125 isolates of Pseudomonas aeruginosa were identified phenotypically from clinical specimens of patients at a tertiary hospital in Jos, Northcentral Nigeria. The isolates were screened for ESBL production using the disk diffusion method of the Clinical Laboratory Standard Institute (CLSI) breakpoints. Phenotypic confirmation of ESBL production was done using the double-disc synergy test. Multiplex PCR was used to detect ESBL genes. Results: Fifty (45.5%) of the 110 isolates of Klebsiella pneumoniae and 9(7.2%) of the 125 isolates of Pseudomonas aeruginosa were ESBL-positive. Typing of 20 representative ESBL isolates (17 Klebsiella and 3 Pseudomonas spp) showed the presence ofblaCTX-M1, blaCTX-M9, and blaSHV genes in these isolates. All 20 (100%) isolates had the blaCTX-M1 gene. The blaSHV gene was detected in 16(80%) while CTX-M9 was detected in 6(30%) of the isolates studied. Conclusion: The study showed that there is a high prevalence of ESBL genes among isolates of Klebsiella pneumoniae and Pseudomonas aeruginosa in North-central Nigeria. This emphasizes the need for continuous surveillance and coordinated infection prevention and control to curtail its spread. [ABSTRACT FROM AUTHOR]

Objective: Raw milk is an important source of nutrients. Therefore, today, there is a great demand for raw milk consumption. The positive side of milk consumption on growth and development cannot be ignored, but unfortunately, pathogens in raw milk are always potential public health risks for transmission pathogens. Bacteria such as Enterobacteriaceae in normal flora can cause serious problems due to their extended-spectrum beta-lactamase (ESBL) production. These bacteria and their resistance genes have been reported in raw milk. In this matter, the aim of the study is to determine the status of blaCTX-M-1, blaCTXM-2, blaTEM and blaSHV genes responsible for the production of ESBL enzyme in Escherichia coli and Klebsiella spp. strains to identify risk factors in raw milk consumption and to gain an understanding of the epidemiology of these resistant strains. Materials and methods: A total of different 50 raw milk samples were collected and subjected to phenotypic microbiological analysis and Real-time PCR targeting blaCTX-M-1, blaCTX-M-2, blaTEM and blaSHV genes. In the phenotypic analyses, suspicious isolates were identified by classical microbiological methods and antibiotic resistance profiles were revealed. Results: These results indicated that raw milk is a potential reservoir for ESBL producing E. Coli, Klebsiella spp. strains are obviously significant. And It was determined that CTX-M-basedESBL genes are predominant in ESBL production. Conclusion: The present study revealed that raw milk is epidemiologically involved in the transmission of ESBL genes. Raw milk could be distributed to ESBL genes widely and is consumed in Şanlıurfa. [ABSTRACT FROM AUTHOR]

Background: Antimicrobial resistance (AMR) in bacterial pathogens is a worldwide concern that demands immediate attention. Most information on AMR originates from high-income countries and little is known about the burden in Africa, particularly Nigeria. Using four sentinel sites (General hospitals) in Lagos State, this study sought to estimate the burden of AMR. Methods: This is a hospital-based surveillance using secondary health care centres. Four sites were randomly selected and included in the study. Clinical isolates were collected over a period of 6 months for each site from August 2020 to March 2021. All isolates were characterised and analysed for resistance to 15 antibiotics using the Kirby-Baur method. Multiplex PCR assay was used for the detection of Extended spectrum beta lactamase genes. Data analysis was done using SPSS version 27.0. Results: Four hundred and ninety-nine (499) patients consented and participated in this study, consisting of 412 (82.6%) females and 87 (17.4%) males. The mean age ± SD of the participants was 33.9 ± 13.8 with a range of 1–89 years. The majority (90.8%) of the participants were outpatients. Two hundred and thirty-two (232) isolates were obtained from 219 samples, comprising of 120 (51.7%) Gram positive and 112 (48.3%) Gram negative organisms. Key bacterial pathogens isolated from this study included Staphylococcus aureus (22.8%), Escherichia coli (16.4%), Staphylococcus spp. (15.9%), Enterococcus spp. (7.3%) and Klebsiella pneumoniae (6.5%). There was high prevalence of multi-drug resistance (79.3%) among the isolates with 73.6% of Staphylococcus aureus phenotypically resistant to methicillin and 70% possessed the MecA gene. 76.5% of Enterococcus spp. isolated were Vancomycin resistant. Overall, resistance to Cephalosporins was most frequently/commonly observed (Cefotaxime 87.5%). Conclusion: A high incidence of AMR was identified in clinical bacteria isolates from selected general hospitals in Lagos State, highlighting the necessity for the implementation of national action plans to limit the prevalence of AMR. Surveillance via collection of isolates has a lot of promise, especially in resource-limited environments. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the association between antimicrobial resistance, ESBL genes, and virulence genes of Salmonella isolates. From 2019 to 2021, a total of 117 Salmonella isolates were obtained from symptomatic chickens in Sichuan Province, China. The strains were tested for antimicrobial resistance and the presence of ESBL according to the Clinical and Laboratory Standards Institute (CLSI) instructions. The presence of ESBL genes and genes for virulence was determined using Polymerase Chain Reaction (PCR). In addition, Multilocus Sequence Typing (MLST) was applied to confirm the molecular genotyping. Moreover, the mechanism of ESBL and virulence gene transfer and the relationships between the resistance phenotype, ESBL genes, and virulence genes were explored. The isolates exhibited different frequencies of resistance to antibiotics (resistance rates ranged from 21.37% to 97.44%), whereas 68.38% and 41.03% of isolates were multi-drug resistance (MDR) and ESBL-producers, respectively. In the PCR analysis, blaCTX-M was the most prevalent ESBL genotype (73.42%, 58/79), and blaCTX-M-55 showed the most significant effect on the resistance to cephalosporins as tested by logistic regression analysis. Isolates showed a high carriage rate of invA, avrA, sopB, sopE, ssaQ, spvR, spvB, spvC, stn, and bcfC (ranged from 51.28% to 100%). MLST analysis revealed that the 117 isolates were divided into 11 types, mainly ST92, ST11, and ST3717. Of 48 ESBL-producers, 21 transconjugants were successfully obtained by conjugation. Furthermore, ESBL and spv virulence genes were obtained simultaneously in 15 transconjugants. These results highlighted that Salmonella isolates were common carriers of ESBLs and multiple virulence genes. Horizontal transfer played a key role in disseminating antimicrobial resistance and pathogenesis. Therefore, it is necessary to continuously monitor the use of antimicrobials and the prevalence of AMR and virulence in Salmonella from food animals and to improve the antibiotic stewardship for salmonellosis.

Abstract Background Klebsiella spp. are important pathogens associated with bacteremia among admitted children and is among the leading cause of death in children

CG258 is the dominant carbapenemase-producing Klebsiella pneumoniae clone worldwide and treatment of infections caused by this clone relies largely on the last-line antibiotics, colistin, and tigecycline. However, the emergence and global dissemination of mcr and tmexCD1 - toprJ1 genes have significantly compromised their clinical applications. CG258 K. pneumoniae carrying both mcr and tmexCD1 - toprJ1 have not been reported. A colistin-resistant strain T698-1 belonging to ST1326, a member of CG258, was isolated from the intestinal sample of a patient and characterized by the antimicrobial susceptibility testing, conjugation assay, WGS and bioinformatics analysis. It was resistant to colistin, tetracycline, aminoglycoside, fluoroqinolone, phenicols, sulfonamide, and some β-lactams, and positive for mcr-8.2 , tmexCD1 - toprJ1 , and ESBL genes (bla DHA– 1 and bla CTX–M– 15). The tmexCD1 - toprJ1 gene cluster was located in an multi-drug resistant (MDR) region flanked by Tn As1 elements on an IncHI1B/FIB plasmid. The genetic context of tmexCD1 - toprJ1 was slightly distinct from previously reported Tn 5393 -like structures, with an IS 26 element disrupting the upstream Tn 5393 and its adjacent genetic elements. The mcr-8.2 gene was inserted into the backbone of an IncFII/FIA plasmid with the genetic context of IS Ecl1 - mcr-8.2 - orf -IS Kpn26. To our knowledge, this is the first report of co-occurrence of mcr-8.2 and tmexCD1 - toprJ1 in a CG258 K. pneumoniae strain. Though this strain is tigecycline sensitive, the acquisition of colistin and tigecycline resistance determinants by the endemic CG258 K. pneumoniae clone still poses a serious public health concern. CG258, which became resistant to multiple last resort antibiotics, would be the next emerging superbug. [ABSTRACT FROM AUTHOR]

Abstract Objective The objective of this study was to determine the proportion of extended spectrum β-lactamase producing gram-negative bacteria (ESBL-GNB) colonizing patients admitted at Mazimbu hospital and Morogoro Regional hospital, in Morogoro, Tanzania. Rectal colonization with ESBL-GNB increases the risks of developing bacterial infections by extra-intestinal pathogenic ESBL-GNB. Results Of the 285 patients investigated, 123 (43.2%) carried ESBL-GNB in their intestines. Five of the 123 ESBL positive patients were colonized with two different bacteria, making a total of 128 ESBL producing isolates. Escherichia coli (n = 95, 74.2%) formed the majority of ESBL isolates. The proportion of CTX-M-1 group genes among ESBL isolates tested was 94.9% (93/98). History of antibiotic use (OR: 1.83, 95% CI: 1.1–3.2, P = 0.03), being on antibiotic treatment (OR: 2.61, 95% CI: 1.5–4.53, P = 0.001), duration of hospital stay (OR: 1.2, 95% CI: 1.1–1.3, P

CG258 is the dominant carbapenemase-producing Klebsiella pneumoniae clone worldwide and treatment of infections caused by this clone relies largely on the last-line antibiotics, colistin, and tigecycline. However, the emergence and global dissemination of mcr and tmexCD1-toprJ1 genes have significantly compromised their clinical applications. CG258 K. pneumoniae carrying both mcr and tmexCD1-toprJ1 have not been reported. A colistin-resistant strain T698-1 belonging to ST1326, a member of CG258, was isolated from the intestinal sample of a patient and characterized by the antimicrobial susceptibility testing, conjugation assay, WGS and bioinformatics analysis. It was resistant to colistin, tetracycline, aminoglycoside, fluoroqinolone, phenicols, sulfonamide, and some β-lactams, and positive for mcr-8.2, tmexCD1-toprJ1, and ESBL genes (blaDHA–1 and blaCTX–M–15). The tmexCD1-toprJ1 gene cluster was located in an multi-drug resistant (MDR) region flanked by TnAs1 elements on an IncHI1B/FIB plasmid. The genetic context of tmexCD1-toprJ1 was slightly distinct from previously reported Tn5393-like structures, with an IS26 element disrupting the upstream Tn5393 and its adjacent genetic elements. The mcr-8.2 gene was inserted into the backbone of an IncFII/FIA plasmid with the genetic context of ISEcl1-mcr-8.2-orf-ISKpn26. To our knowledge, this is the first report of co-occurrence of mcr-8.2 and tmexCD1-toprJ1 in a CG258 K. pneumoniae strain. Though this strain is tigecycline sensitive, the acquisition of colistin and tigecycline resistance determinants by the endemic CG258 K. pneumoniae clone still poses a serious public health concern. CG258, which became resistant to multiple last resort antibiotics, would be the next emerging superbug.

Background: Extended spectrum beta-lactamase (ESBL) has been described in Escherichia coli strains that have been isolated from humans and animals; it has induced a main concern with antibiotic resistance in serious bacterial infections. Aims: This study aimed to investigate the frequency of ESBL-producing E. coli (EPE) strains in meat and intestinal contents of turkey, and to compare the antibiotic resistance profile between EPE and non-EPE strains. Methods: Totally, 70 and 110 E. coli strains were isolated from turkey meat and turkey intestinal content samples, respectively. To determine EPE strains, double disc synergy test was applied by that 20 and 22 EPE strains were finally identified in meats and intestinal contents of the turkeys, respectively. Antibiotic susceptibility was exerted using disc diffusion method. Escherichia coli isolates were then characterized for virulence genes (stx-1 and stx-2) and ESBL genes (TEM, SHV, and CTX-M). Results: None of the E. coli strains harbored stx genes. The EPE strains in comparison with non-EPE strains were significantly more resistant to ciprofloxacin (47.6 vs 26.5%), tetracycline (80.9 vs 67.3%), ampicillin (47.6 vs 22.4%), penicillin (23.8 vs 10.2%), ceftazidime (57.1 vs 16.3%), ceftriaxone (38.1 vs 18.4%), and cefotaxime (47.6 vs 8.2%). The majority of EPE strains carried CTX-M gene. SHV showed the lowest frequency and it was not detected in EPE strains isolated from the intestinal contents. In this study, 75% of TEM-producing E. coli strains and 33% of SHV-producing E. coli strains were resistant to ampicillin. In addition, 41.7% of TEM-producing E. coli strains were resistant to penicillin, and 76.9% of CTX-producing E. coli were resistant to cefotaxime. Furthermore, 4.7% of EPE strains isolated from turkey meat were imipenem resistant. Conclusion: The resistance to cefotaxime and imipenem in EPE strains induces a concern in growing antibiotic resistance against broad spectrum antibiotics in E. coli strains. [ABSTRACT FROM AUTHOR]

ABSTRACT: The extended-spectrum cephalosporin resistant E. coli from food animals transferring to community settings of humans causes a serious threat to public health. Unlike phylogroup B2 E. coli strains, the clinical significance of isolates in phylogroup F is not well revealed. Here, we report on a collection (n = 563) of phylogroup F E. coli isolates recovered from chicken colibacillosis tissues and retail raw chicken meat samples in Eastern China. There was an overlapped distribution of MLST types between chicken colibacillosis-origin and meat-source phylogroup F E. coli, including dominant STs (ST648, ST405, ST457, ST393, ST1158, etc). This study further investigated the presence of extended-spectrum β-lactamase (ESBL/pAmpC) producers in these chicken-source phylogroup F E. coli strains. The prevalence of extended-spectrum cephalosporin resistant strains in phylogroup F E. coli from chicken colibacillosis and raw meat separately accounted for 66.1 and 71.2%. The resistance genotypes and plasmid replicon types of chicken-source phylogroup F E. coli isolates were characterized by multiplex PCR. Our results revealed β-lactamase CTX-M, OXA, CMY and TEM genes were widespread in chicken-source phylogroup F E. coli, and blaCTX-M was the most predominant ESBL gene. Moreover, there was a high prevalence of non-lactamase resistance genes in these β-lactam-resistant isolates. The replicons IncB/O/K/Z, IncI1, IncN, IncFIC, IncQ1, IncX4, IncY, and p0111, associated with antibiotic-resistant large plasmids, were widespread in chicken-source phylogroup F E. coli. There was no obvious difference for the populations, resistance spectrums, and resistance genotypes between phylogroup F E. coli from chicken colibacillosis tissues and retail meats. This detail assessment of the population and resistance genotype showed chicken-source phylogroup F E. coli might hold zoonotic risk and contribute the spread of multidrug-resistant E. coli to humans.

Background: Klebsiella spp. are important pathogens associated with bacteremia among admitted children and is among the leading cause of death in children < 5 years in postmortem studies, supporting a larger role than previously considered in childhood mortality. Herein, we compared the antimicrobial susceptibility, mechanisms of resistance, and the virulence profile of Klebsiella spp. from admitted and postmortem children.Methods: Antimicrobial susceptibility and virulence factors of Klebsiella spp. recovered from blood samples collected upon admission to the hospital (n = 88) and postmortem blood (n = 23) from children < 5 years were assessed by disk diffusion and multiplex PCR.Results: Klebsiella isolates from postmortem blood were likely to be ceftriaxone resistant (69.6%, 16/23 vs. 48.9%, 43/88, p = 0.045) or extended-spectrum β-lactamase (ESBL) producers (60.9%, 14/23 vs. 25%, 22/88, p = 0.001) compared to those from admitted children. blaCTX-M-15 was the most frequent ESBL gene: 65.3%, 9/14 in postmortem isolates and 22.7% (5/22) from admitted children. We found higher frequency of genes associated with hypermucoviscosity phenotype and invasin in postmortem isolates than those from admitted children: rmpA (30.4%; 7/23 vs. 9.1%, 8/88, p = 0.011), wzi-K1 (34.7%; 8/23 vs. 8%; 7/88, p = 0.002) and traT (60.8%; 14/23 vs. 10.2%; 9/88, p < 0.0001), respectively. Additionally, serine protease auto-transporters of Enterobacteriaceae were detected from 1.8% (pic) to 12.6% (pet) among all isolates. Klebsiella case fatality rate was 30.7% (23/75).Conclusion: Multidrug resistant Klebsiella spp. harboring genes associated with hypermucoviscosity phenotype has emerged in Mozambique causing invasive fatal disease in children; highlighting the urgent need for prompt diagnosis, appropriate treatment and effective preventive measures for infection control. [ABSTRACT FROM AUTHOR]

urpose: to evaluate the epidemiological relationship between 3rd generation cephalosporin resistant Enterobacter cloacae blood isolates collected from patients in the University Hospital in Varna city during the period March 2014 and January 2017 and to characterize the ESBLs production in these isolates. Materials and methods: a total of 47 consecutive (nonduplicate) 3rd generation cephalosporin resistant isolates of Enterobacter cloacae, obtained from blood samples of patients admitted in different wards in Varna University Hospital, were investigated. Antimicrobial susceptibility to set of antimicrobial agents was tested by disc diffusion method and Phoenix (BD), and the results were interpreted according to EUCAST guidelines 2017. Identification of ESBL encoding genes was performed by PCR and sequencing. Isolates were genotyped by ERIC PCR. Results: The antimicrobial susceptibility in the whole collection of isolates, shown in decreasing order, is as follows: amikacin, 97.8% < levofloxacin, 76.6% < trimethoprime/ sulphometoxazole, 40.4% < ciprofloxacin, 19% < gentamicin, 8.4% < cefepime, 4.2% < piperacillin/ tazobactam, tobramycin, 2.1%. Multidrug resistance was detected in 70.2% of the isolates. The most widespread enzyme was CTX-M-15, found in 95.5% (n=43). Nine different ERIC types were detected. The dendrogram of similarity revealed three main clones of E. cloacae: Clone I, comprising two closely related subclones (ERIC type A and Aa) (similarity coefficient 0.92), was predominant, detected in Haematology (n=9), Haemodialysis (n=8), ICU (n=6), Cardio surgery (n=3), Pulmonology (n=4) and Gastroenterology (n=1); Clones II (ERIC type C) and III were presented by 5, and 3 isolates with identical profiles, obtained from patients, hospitalized in different wards. The ERIC profiles K, L, M and P, were found in single isolates only and were interpreted as sporadic. Conclusions: multi-drug resistance in E. cloacae was associated with successful intrahospital dissemination of three CTX-M-15 producing E. cloacae clones. Clone I was predominant, demonstrating high cross-transmission, epidemic and invasive potential. BlaCTX-M-15 was identified as a major mechanism of resistance to 3rd generation cephalosporins in E. cloacae.

Objective: The objective of this study was to determine the proportion of extended spectrum β-lactamase producing gram-negative bacteria (ESBL-GNB) colonizing patients admitted at Mazimbu hospital and Morogoro Regional hospital, in Morogoro, Tanzania. Rectal colonization with ESBL-GNB increases the risks of developing bacterial infections by extra-intestinal pathogenic ESBL-GNB. Results: Of the 285 patients investigated, 123 (43.2%) carried ESBL-GNB in their intestines. Five of the 123 ESBL positive patients were colonized with two different bacteria, making a total of 128 ESBL producing isolates. Escherichia coli (n = 95, 74.2%) formed the majority of ESBL isolates. The proportion of CTX-M-1 group genes among ESBL isolates tested was 94.9% (93/98). History of antibiotic use (OR: 1.83, 95% CI: 1.1–3.2, P = 0.03), being on antibiotic treatment (OR: 2.61, 95% CI: 1.5–4.53, P = 0.001), duration of hospital stay (OR: 1.2, 95% CI: 1.1–1.3, P < 0.001) and history of previous admission (OR: 2.24, 95% CI: 1.2–4.1, P = 0.009) independently predicted ESBL-GNB carriage. [ABSTRACT FROM AUTHOR]

Shiga toxin type 2e (Stx2e) Escherichia coli is the causative factor of diarrhea and edema in swine. The aims of this study were to determine the prevalence of Stx2e-producing E. coli isolates and to characterize isolates from clinical cases of pig colibacillosis and healthy swine. During the 11 years of the study (2006–2017), a total of 233 Stx2e-producing isolates were detected−230 out of 2,060 (11.16%) E. coli isolated from diseased pigs and 3 out of 171 (1.75%) from healthy swine. Stx2e-producing isolates were indeed more present in clinical colibacillosis cases than in healthy pigs (p = 0.0002). The predominant serogroup was O139 (79.82%) and the most common fimbrial factor present in these isolates was F18 (177 isolates), followed by F6 (5 isolates). The enterotoxins LTI, STa, and STb were detected in 10.43, 41.73, and 48.26% of the isolates, respectively. The predominant virotypes F18-Stx2e and -STa-STb-Stx2e were similarly present in weaners (33.33 and 35.52%) and finishers (38.30 and 25.53%). Among isolates from diseased pigs, O139 and F18 were the more frequently identified serogroup and virulence factor, respectively. Of the tested 230 Stx2e-producing isolates isolated from diseased pigs, 29 (12.60%) harbored genes encoding ESBL, particularly TEM (79.30%), CTX-M1 (17.20%), and CMY-2 (3.40%). Antimicrobial resistance to tetracycline was the most common characteristic (98.25%), followed by ampicillin (93.91%), cephalotin (90.43%) and trimethoprim/sulfamethoxazole (82.17%). Our results showed that Stx2e-producing E. coli were more frequently associated with clinical forms of colibacillosis, with minimal probability to isolate these isolates from healthy pigs.

Background: The present study was aimed for determination the prevalence of Extended- Spectrum β- Lactamase (ESBL) genes from Acinetobacter baumannii isolates obtained from hospital-acquired infection at Basra hospitals and to determine the relationship ESBL genes with Multidrug Resistance (MDR) among these A. baumannii isolates. Methodology: A total 120 samples were collected from burn, urine, Intensive Care Unit (ICU) and pediatric wards at different Basra hospitals and these were identified depending on standard microbiological methods with VITEK-2 system. The high percentages were (31.5%) isolates of Staphylococcus aureus followed by pseudomonas aeruginosa (27.6%) and Acinetobacter baumannii (25.3%). Results: Furthermore, antimicrobial susceptibility test and Multi-Drug Resistance of A. baumannii were achieved according to CLSI method. It has been found that A. baumanii had high resistance that Cefotaxime (94%), Imipenem (91%), Cefoxitin (85%), Merpenem (82%), Gentamicin (76%), Aztreonam (73%), Ciprofloxacin (70%) and Ampicillin (61%). On the other hand, high percentage (84.6%) of multidrug resistance was observed in A. baumannii. In addition, phenotypic expression of ESBL- A. baumannii was demonstrated by Double Disc Synergy Test (DDST) method in (73%) isolates of MDR- A. baumanii . ESBL genes (bla- TEM, bla- SHV, bla- CTX) of these isolates were detected by Polymerase Chain Reaction (PCR) assay. The most frequent genes of A. baumannii were bla- TEM genes 21(64%), followed by bla-SHV genes 17(52%) and bla- CTX genes 14(42%). Conclusion: From this study, we concluded that significant relationship can be occurred between MDR isolates of A. baumannii with ESBL genes among environment of Basra hospitals. [ABSTRACT FROM AUTHOR]

Escherichia coli is considered one of the most common agents associated with neonatal diarrhea in piglets. The aim of this work was to characterize the pathogenic and antimicrobial resistance (AMR) profiles of 122 E. coli strains isolated from pigs suffering diarrhea (n = 94) and pigs without diarrhea (n = 28) of 24 farms in Spain. Virulence factors, toxins and AMR (ESBL and colistin) genes and AMR phenotypes of E. coli isolates were analyzed. Low prevalence of pathogenic E. coli strains (26%) was found in both groups. However, ETEC and VTEC strains were more frequently isolated from diarrheic piglets. Irrespectively of diarrhea occurrence, 97.5% of the strains showed a multidrug-resistance (MDR) profile to aminopenicillins, sulfonamides and tetracyclines. It was found that 22% of E. coli was CTX-M+, with CTX-M-14 being the principal allelic variant. Remarkably, 81.5% of CTX-M+ strains were isolated from diarrheic animals and presented an extended MDR profile to aminopenicillins, quinolones and aminoglycosides. Finally, low frequencies of colistin resistance genes mcr-1 (4/122) and mcr-4 (1/122) were found. MDR E. coli strains are circulating in pig farms of Spain, representing a serious threat to animal and public health. More appropriate diagnostic approaches (genetic and AMR phenotypic analysis) should be implemented in animal health to optimize antibiotic treatments. [ABSTRACT FROM AUTHOR]

Global prevalence of ESBL-biotypes poses a serious threat to public health as a result of severity and morbidity caused by beta-lactam encoded Escherichia coli. Therefore, the prevalent shiga toxigenic Escherichia coli of ESBL variant was investigated in various retailed food animals and cooking materials. A total of 823 samples consisting of raw meat (297) and fish (132) samples retailed at various major markets in Ibadan were collected and 394 swabs were taken from the butchers' processing tables and utensils used in retailing meat and fish. The samples were cultured and biotyped for Escherichia coli. Serological and PCR assay were used to identify O157:H7 variant and antibiotics resistant determinants. Genetic relatedness of characterized E. coli O157 from human and meat products was evaluated with phylogenetic analysis. Of all the isolates, 130 (15.8%) were E. coli and only 8 (1.0) were O157:H7 while 4 (50%) were resistant to one or more antibiotics with resistance index ranging from 0.1 to 0.5. More than 25% E. coli O157:H7 were resistant to Ampicillin, Pefloxacin and Gentamicin and blaSHV and blaCTX-M were detected in 1/8 (12.5%) of E. coli O157:H7 and blaTEM 3/8 (37.5%) respectively. Only 1 genotyped human Escherichia coli.0157:H7 clustered with beef strain There is evidence of blaTEM encoded E. coli O157:H7 causing infection in human from food animals retailed in many markets within various communities. Therefore, urgent surveillance with public health education, food, and environmental hygiene are highly needed to prevent its spread. [ABSTRACT FROM AUTHOR]

Despite the high morbidity and mortality which the bacterial cause of typhoid fever, few reports have highlighted the subject outbreaks multiple antibiotic resistance (MAR) of these bacteria producing extended-spectrum β-lactamases (ESBL) in Asia, especially in Iraq. Salmonella typhi strains were identified by morphological and biochemical tests, phenotypic, and genotypic confirm by the Vitek-2 system and PCR assay respectively. The results of 189 diarrhea specimens were 56 (29.6%) identity as S. typhi strains. Fierce resistance exterminated S. typhi against most antibacterial drugs, with the exception carbapenems. Whole S. typhi strains (100%) were considered to be multi-drug resistant (MDR) phenotype, which found to be either 45 (80.4%) MDRor11 (19.6%) XDR.MAR index values of 56 S. typhi strains had (100% > 0.2) ranged (0.39-0.92) out of 1 which maximum MAR index. The phenotypic test revealed that ESBL production was recognized in 58.9% (33) strains. The PCR results demonstrated that 71.4% (40), 48.2% (27), and 19.6% (11) of strains were positive results for the blaTEM, blaCTX-M-1, and blaSHV respectively. None of the strains were positive for the group 2, 8, 9, and 25 of CTX-M. The simultaneous incidence of combined β-lactamases (TEM, CTX-M-1, and SHV) were documented in 11 (19.6%) S. typhi strains, and (TEM and CTX-M-1) in 23 (41.1%) S. typhi strains. Higher dissemination of the resulting resistance from S. typhi, which mediates ESBL, constitutes a major global threat to public health, especially reducing infections bacterial caused to typhoid fever. Therefore, the limited treatment options available in the treatment of such infections, essentially with the proliferation of strains exhibit XDR, which have very high MAR values indicating their exposure to a high level of these drugs in their environment. [ABSTRACT FROM AUTHOR]

Infections due to carbapenem-resistant Escherichia coli (CREC) are problematic due to limitation in treatment options. Combination therapies of existing antimicrobial agents have become a reliable strategy to control these infections. In this study, the synergistic effects of meropenem in combination with aminoglycosides were assessed by checkerboard and time-kill assays. Of the 35 isolates, 19 isolates (54.3%) were resistant to carbapenems (imipenem and meropenem) with the MIC ranges from 16 to 128 µg/mL. These isolates were resistant to almost all antibiotic classes. Molecular characteristics revealed co-harboring of carbapenemase (blaNDM-1, blaNDM-5 and blaOXA-48) and extended-spectrum β-lactamases (ESBL) genes (blaCTX-M, blaSHV and blaTEM). The checkerboard assay displayed synergistic effects of meropenem and several aminoglycosides against most CREC isolates. Time-kill assays further demonstrated strong synergistic effects of meropenem in combination with either amikacin, gentamicin, kanamycin, streptomycin, and tobramycin. The results suggested that meropenem in combination with aminoglycoside therapy might be an efficient optional treatment for infections cause by CREC.

Aims: Manila clam (Ruditapes philippinarum) is one of the most popular seafood in Korea, owing to their unique taste and nutritional value. This study aimed to disclose the antibiotic and heavy metal resistance characteristics of Aeromonas spp. isolated from marketed Manila clam in Korea. Methods and results: A total of 36 Aeromonas spp. strains were isolated and subjected to two tests: an antibiotic disk diffusion test to determine their resistance to antibiotics, and a broth dilution test to determine their resistance to heavy metals. PCR‐based amplification was performed to detect the resistance genes. A high level of resistance to ampicillin (100%) and cephalothin (89%) was observed, while 42, 39, 36 and 36% of the isolates were resistant to oxytetracycline, imipenem, nalidixic acid and tetracycline respectively. In addition, among the tested heavy metals, cadmium (Cd) recorded the highest resistance rate (61%), followed by chromium (Cr) (50%), lead (Pb) (47%) and copper (Cu) (37%). However, mercury (Hg) resistance was not observed. PCRs revealed the occurrence of blaTEM, blaSHV, blaCTX‐M, qnrS, tetB, tetE, aac(6′)‐Ib, strA‐strB and intI1 genes among 100, 31, 31, 78, 78, 89, 25, 50 and 72% of the isolates respectively. Moreover, heavy metal resistance genes, copA, merA and czcA were detected in 25, 47 and 61% of the isolates respectively. Conclusions: The results suggest the importance of multi‐drug and heavy metal‐resistant aeromonads in Manila clam to assess the consumer safety and public health. Significance and Impact of the Study: This study is the first to elaborate on the importance of multi‐drug and heavy metal‐resistant aeromonads in Manila clam. Particularly, the presence of extended‐spectrum‐β‐lactamase genes and other antibiotic resistance genes intensifies the possible health risks and may complicate therapeutic treatments upon infection, while heavy metal resistance suggests possible heavy metal exposure. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the phenotypic antibiotic susceptibility patterns, extended-spectrum β- lactamase (ESBL) genes and genotypic profiles of ESBL-positive Escherichia coli strains isolated from urine samples obtained from outpatients with urinary tract infection in Turkey. A total of 120 E. coli strains during 2017, 2018, and 2019 (40 patients per year) were examined for antibiotic susceptibility patterns by disc diffusion method, for ESBL genes using PCR and sequencing and for molecular typing by pulsed-field gel electrophoresis (PFGE) method. The isolates were evaluated for their sensitivity to 21 different antibiotics. Four different antimicrobial resistance patterns were determined according to antibiotic susceptibility status of the isolates. The β- lactamase genes detected in the isolates were CTX-M-15 + OXA-1 (n= 14), CTX-M-15 (n= 24), TEM-1 + CTX-M-15 (n= 52), TEM- 1 + SHV-12 (n=6), SHV-12 1 (n= 6), TEM-1 + CTX-M-1 (n= 6), TEM-1 + CTX-M-16 (n= 6) and TEM-1 + CTX-M-9 (n= 6). The CTX-M-15 was the most prevalent ESBL enzyme in the isolates. As a result of PFGE analysis performed by XbaI enzyme restriction process, one major PFGE profile and three main groups (Group I-II-III) were observed. While antibiotic resistance profiles of the strains showed four groups (RI-RII-RIII-RIV), PFGE band profiles showed a major group (90% similarity ratio). High ESBL production and decreased susceptibility to broad-spectrum cephalosporins were observed in E. coli strains. In addition, PFGE analysis showed high clonal similarity among E. coli isolates. [ABSTRACT FROM AUTHOR]

The emergence and spread of antimicrobial resistance genes and resistant bacteria do not recognize animal, human, or geographic boundaries. Addressing this threat requires a multidisciplinary approach involving human, animal, and environmental health (One Health) sectors. This is because antimicrobial agents used in veterinary medicine have been reported to be the same or similar to those in human medicine use. Extended-spectrum β-lactamase (ESBL) E. coli is a growing public health problem worldwide, and the agri-food industry is increasingly becoming a source of clinically important ESBL bacteria. Accordingly, the aim of this study was to investigate the occurrence and characteristics of ESBL-producing E. coli from dairy cattle, milk, and the farm environment. E. coli isolates were identified by their 16sRNA, and their ESBL production was confirmed using ESBL–CHROMagar media and the double disk diffusion method. Genotypes of ESBL producers were characterized using multiplex polymerase chain reaction (mPCR) assay. It was found that 18 (4.8%) of the total samples were positive for ESBL-producing E. coli. Of these, 66.7% were from milk, and 27.8% and 5.5% were from the farm environment and faecal samples, respectively. Predominant ESBL genotypes identified were a combination of both TEM and CTX-M in eight out of 18 (44.4%) isolates. Four (22.2%) isolates produced the CTX-M gene, two (11.1%) isolates produced the TEM gene, and four (22.2%) remaining isolates produced the ESBL genes other than TEM, SHV, CTX-M, and OXA. The SHV and OXA gene were not detected in all 18 isolates. In all, there were four profiles of genetic similarity. The occurrence of these genotypes in indicator organisms from dairy cattle, milk, and the farm environment further re-enforced the potential of food-animals as sources of ESBL-producing E. coli infection in humans via the food chain. Thus, there is the need for the adoption of a tripartite One Health approach in surveillance and monitoring to control antimicrobial resistance.

Escherichia coli is considered one of the most common agents associated with neonatal diarrhea in piglets. The aim of this work was to characterize the pathogenic and antimicrobial resistance (AMR) profiles of 122 E. coli strains isolated from pigs suffering diarrhea (n = 94) and pigs without diarrhea (n = 28) of 24 farms in Spain. Virulence factors, toxins and AMR (ESBL and colistin) genes and AMR phenotypes of E. coli isolates were analyzed. Low prevalence of pathogenic E. coli strains (26%) was found in both groups. However, ETEC and VTEC strains were more frequently isolated from diarrheic piglets. Irrespectively of diarrhea occurrence, 97.5% of the strains showed a multidrug-resistance (MDR) profile to aminopenicillins, sulfonamides and tetracyclines. It was found that 22% of E. coli was CTX-M+, with CTX-M-14 being the principal allelic variant. Remarkably, 81.5% of CTX-M+ strains were isolated from diarrheic animals and presented an extended MDR profile to aminopenicillins, quinolones and aminoglycosides. Finally, low frequencies of colistin resistance genes mcr-1 (4/122) and mcr-4 (1/122) were found. MDR E. coli strains are circulating in pig farms of Spain, representing a serious threat to animal and public health. More appropriate diagnostic approaches (genetic and AMR phenotypic analysis) should be implemented in animal health to optimize antibiotic treatments.

The rapid increase of extended spectrum beta-lactamases (ESBLs) producing Pseudomonas aeruginosa in hospital acquired infections has led to limitations of treatment options and the emergence of antimicrobial resistance becomes a global problem. In this study, the role of ESBL enzymes and their genes in the antimicrobial resistance of P. aeruginosa from burns infections was investigated. One hundred and fifty samples of burns in four hospitals in Baghdad, Iraq were collected. The colonies on Cetrimide agar were used as preliminary identification; suspected colonies were identified by API 20NE System and confirmed with a Vitek-2 system. Double disk synergy test (DDST) was used for phenotypically detection of ESBL producing isolates. The antimicrobial susceptibility testing of P. aeruginosa isolates were done against eight beta-lactam antibiotics. Additionally, the ESBL genes were determined by polymerase chain reaction (PCR) according to the specific primers of the blaTEM, blaCTX-M, blaSHV, blaVEB and blaPER genes. The results revealed thatP. aeruginosa was isolated from 66 samples (44%). The total percentage of P aeruginosa which exhibited ability for ESBL activity was 54.5% (36/66). The most of tested isolates demonstrated a highest resistance for Piperacillin, Cefepime and Cefotaxime followed by Ceftazidime. Beta-lactamase genes frequencies in ESBL-producing isolates were recorded (blaTEM86.1%, blaSHV 52.3%, blaVEB 44.4%, blaCTX-M 41.6% and blaPER33.3%). Sequencing the predominant ESBL gene (blaTEM) confirmed the accuracy of the PCR products and indicated to the presence of the variants blaTEM21 in the most local isolates of P aeruginosa. It was concluded that the presence of high rates of ESBL genes inP. aeruginosa isolated from burns infections increase the risk of emergence more multidrug resistant strains and this leading to therapy failure. [ABSTRACT FROM AUTHOR]

Extended spectrum β-lactamases (ESBLs) are a group of enzymes that can hydrolyze a variety of β-lactams including fourth generation cephalosporins and compromise the efficacy of all β-lactams, except cephamycins and carbapenems. In the worldwide, the ESBL group of enzymes are found widely and causes a severe infection on human health which leads to various diseases. This review primarily focusses on analyzing the prevalence and drug resistance patterns in the African continent. From the earlier reported data shown only the minimal amount of surveillance information's has been summarized with respect to antimicrobial resistance on ESBLs producing Enterobacteriaceae both in hospital and community settings. To bring the present scenario in limelight, the present study explores the prevalence of ESBL-producing Enterobacteriaceae in various countries in Africa and specifically, to identify most common ESBL genes in hospital and community. The observation was initiated with the exhaustive literature search using PubMed and other databases to broaden the study from the earlier investigations in the African countries concerned about the prevalence rate of ESBL producing Enterobacteriacea e. Further, this study was extended to review various hypothesis of the hydrolytic mechanism, which was detailed by several authors performed earlier through computational approaches. Interestingly, the ESBLs class A and D were found to be common classes in Africa, with the gene CTX-M-15 being most prevalent. Notably, the present review highlights the prevalence on individual countries in Africa and it is extremely significant to prevent the dissemination of ESBL-producing Enterobacteriaceaea. Hence, this review on surveillance will be the benchmark to enhance the research on antimicrobial resistance patterns for all classes and genes. Furthermore, explored in-sights in this paper will be helpful for the further investigations to develop quicker, cost effective, and reliable diagnostic strategies and new effective therapies. [ABSTRACT FROM AUTHOR]

In this study, 97 Escherichia coli strains isolated from urinary tract infections were evaluated in terms of phenotypic diversity, susceptibility to sixteen antibiotics, and extended spectrum of beta lactamase (ESBL) characteristics. The bacteriophage interactions was used to identify the relations of the E.coli isolates. Results showed that 21 of the 76 typable strains revealed 19 different phage types. Phage types of 21 strains could not be determined. Antibiotic susceptibility tests, performed against sixteen antibiotics, showed that although the isolates revealed 44 different types of resistance profile, the strains showed the greatest resistance to cephalothin( 54.6%), followed by tetracycline (53.6%), nalidixic acid(44.3%), and aztreonam and ofloxacin (29.8%). There was no resistance to amikacin and meropenem, and all strains were susceptible to meropenem. ESBL detection conducted by double disc synergy and multiplex polymerase chain reaction methods showed that 13 of 97 (13.4%) strains were ESBL-producing. Of the 13 ESBL-producing isolates, two carried blaCTX-M, six blaTEM, five blaOXA, and one blaTEM and blaSHV at same time. We concluded that lytic phages could not be successful for typing the strains phenotypically. The monitoring of antimicrobial resistance levels and antimicrobial usage in humans should be an integral part of the prevention and control of antimicrobial resistance. [ABSTRACT FROM AUTHOR]

Copyright of Revue de Médecine Vétérinaire is the property of Ecole Nationale Veterinaire de Toulouse and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The dissemination of drug-resistant bacteria into different environments has posed a grave threat to public health, but data on the spread of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli ( E. coli) from animal farms to the receiving river are limited. Here, 57 ESBL-producing E. coli isolated from a pig farm and the receiving river were analyzed in terms of drug resistance, ESBL genes, and enterobacterial repetitive intergenic consensus (ERIC). The results showed that ESBL-producing E. coli from swine feces and downstream water of the pig farm outfall overlapped substantially in drug resistance and ESBL genes. Additionally, six ESBL-producing E. coli from the downstream water exhibited 100 % genetic similarity with strains from the swine feces. In conclusion, effluents of animal farms are a likely contributor to the presence of ESBL-producing E. coli in aquatic environments. [ABSTRACT FROM AUTHOR]

Background Multidrug-resistant ( MDR) gram-negative bacilli pose a serious and rapidly emerging threat to recipients of solid organ transplants ( SOTs). However, extended-spectrum β-lactamases ( ESBLs), as one of the cardinal mechanisms of resistance to antimicrobial agents in SOT recipients, remain obscure. The aim of this study was to investigate the prevalence of strains producing ESBLs in SOT patients with MDR gram-negative bacilli infections and to identify the ESBL genes carried by them. Materials and methods Isolates from various clinical specimens of SOT recipients were identified using the VITEK 2 system, and their antibiotic sensitivity was determined by the 2-fold agar dilution method. Isolates suspected of producing ESBL enzymes were tested by an ESBL phenotypic confirmatory method, and the ESBL genotypes were determined by the polymerase chain reaction and sequencing. Results A total of 80 MDR gram-negative strains were isolated from 350 SOT recipients. Among these strains, 42 (52.5%) had an ESBL-positive phenotype; 33 (42.3%) patients with ESBL-positive infection were found. Molecular analysis showed that most of the isolates harbored bla CTX-M-9 (78.6%), bla TEM (81.0%), and bla SHV (69.0%) genes. All the ESBL-producing strains were susceptible to carbapenems. Conclusions MDR gram-negative isolates from SOT recipients are frequently ESBL producers. TEM and CTX-M9 were the predominant ESBL types. [ABSTRACT FROM AUTHOR]

Abstract: Plasmid encoded bla SHV enzymes represent an important sub-group of class A β-lactamases causing an ESBL-phenotype which is increasingly found in Enterobacteriaceae including Klebsiella pneumoniae. The chromosomally encoded β-lactamase bla LEN and bla OKP enzymes, which so far only have been found in K. pneumoniae, do not hydrolyse extended-spectrum cephalosporins. In the present study, multiple displacement amplified DNA derived from 20 K. pneumoniae clinical isolates with a bla SHV-like genotype was used in a universal SHV PCR assay using SP6- (forward) and T7- (reverse) sequence-tagged primers. Identification and differentiation of bla SHV, bla LEN and bla OKP genes was obtained by bi-directional amplicon sequencing using SP6- and T7-specific primers. Three well characterised K. pneumoniae strains having a SHV-genotype were included in the study. The bi-directional amplicon sequencing, covering ∼800bp (∼93%) of the bla SHV, bla LEN and bla OKP enzyme encoding sequences, allowed for an unequivocal discrimination of SHV, LEN and OKP genes. Moreover, sequencing revealed the presence of bla SHV allelic variants in six K. pneumoniae isolates in which the amplicons had to be cloned accordingly. Based on deduced amino-acid sequences, a dendrogram was constructed. Seventeen out of 20 K. pneumoniae isolates with an ESBL-phenotype formed a SHV-like cluster, two were LEN-like, and one isolate was OKP-like. The PCR-based molecular typing method described here enables a rapid, reliable and cost-effective identification and differentiation of bla SHV, bla OKP and bla LEN genes. [Copyright &y& Elsevier]