Bla CTX Research Articles

Monitoring Multi-Drug Resistant Klebsiella pneumoniae in Kitagata Hot Spring, Southwestern Uganda: A Public Health Implication.

The concerning frequency of K. pneumoniae in various recreational settings, is noteworthy, especially regarding multi-drug resistant (MDR) strains. This superbug is linked to the rapid spread of plasmids carrying these resistance genes. The objective of this study was to evaluate the spatiotemporal prevalence of MDR-K. pneumoniae in the Kitagata hot spring, Southwestern Uganda. A laboratory-based descriptive longitudinal study was conducted between May and July 2023. During rainy and dry seasons, we collected eighty water samples in the morning and evening from the hot spring. The temperature at each point was measured prior to sample collection, and two samples were obtained at varying depths. 5 mL of each homogenized sample were pre-enriched in brain heart infusion broth, and subsequently in both blood and violet red bile agar. The Kirby-Bauer disk diffusion method was performed, followed by the detection of carbapenemase (CR) and extended-spectrum β-lactamase (ESBL) production. Polymerase chain reaction showed resistance genes viz. bla TEM, bla CTX-M and bla KPC. Data were analyzed using SPSS-20 to obtain chi-square tests and regression analysis. K. pneumoniae accounted for 30.0% of isolates obtained from Kitagata hot springs, with all isolates classified as multi-drug resistant. All isolates were resistant to ampicillin, rifampicin, ceftazidime, and azithromycin (79.2%). Additionally, 95.8% of isolates harbored bla TEM gene alone and both bla TEM and bla CTX genes, followed by bla KPC alone (33.3%), with 25% harboring all three resistance genes. During the dry season, K. pneumoniae had a higher prevalence (35.0%) compared to the wet season (25.0%). The prevalence of MDR-K. pneumoniae significantly increased over the course of the study. The presence of the three studied resistance genes in the isolates showed a positive correlation with the second phase of sample collection and the dry season but exhibited a negative correlation with temperature, except for isolates harboring either bla TEM alone or bla TEM+KPC+CTX genes. Kitagata hot spring serves as a hotspot for continuous dissemination and acquisition of MDR-K. pneumoniae harboring resistance genes that encode for ESBL and CR production. The healthcare sector ought to implement an ongoing monitoring and surveillance system as well as robust antimicrobial resistance stewardship programs aimed at delivering health education to the community.

Analysis of the Frequency, Antibiotic Susceptibility, and Related Genes among Foodborne Pathogenic Bacteria Isolated from Hospital Refrigerators in Tehran, Iran.

Hospital refrigerators as essential food storage can be important source of food contamination. We aimed to investigate the frequency and antibiotic susceptibility of the pathogenic bacteria in three hospital refrigerators in Tehran. This study was performed on 254 samples, collected from 60 refrigerators of the various wards of three hospitals, A, B, and C, in Tehran, Iran from 2020 to 2021. Following isolation and identification of isolates, the antibiotic susceptibility pattern was determined. PCR-based assays were used to screen the presence of antibiotic resistance genes of resistant isolates. From 254 collected samples, 236 samples (92.9%) were contaminated. Most strains were isolated from refrigerators with poorly cleaned, temperatures above 8 °C in non-critical wards. Most bacteria belonging to Enterobacteriaceae (68.8%), followed by Staphylococcus (11.9%), and Enterococcus (10.6%), while the frequency of non-Enterobacteriaceae isolates was 8.9%. The highest antibiotic resistant bacteria were in extended spectrum beta-lactamase (ESBL) 9.7%, vancomycin-resistant enterococci (VRE) 5.3%, methicillin-resistant S. epidermidis (MRSE) 0.4%, and methicillin-resistant S. aureus (MRSA) 0.4%, respectively. The bla OXA-48, bla CTX, and bcla TEM genes were found only in 10% of Enterobacteriaceae isolates. The bla OXA-51 gene was found in all non-Enterobacteriaceae isolates. The vanA and mecA genes were detected in antibiotic-resistant Enterococcus and Staphylococcus. Our findings suggests major concern about cross-contamination and the emergence of antibiotic-resistant isolates as a potential health threat with hospital refrigerators origin. More attention to hospital refrigerators cleaning is necessary to prevent foodborne diseases and nosocomial infections.

Prevalence and molecular characterization of multi-resistant Escherichia coli isolates from clinical bovine mastitis in China

Different antibiotics are used to treat mastitis in dairy cows that is caused by Escherichia coli (E. coli). Antimicrobial resistance in food-producing animals in China has been monitored since 2000. Surveillance data have shown that the prevalence of multiresistant E. coli in animals has increased significantly. This study aimed to investigate the occurrence and molecular characteristics of resistance determinants in E. coli strains (n = 105) obtained from lactating cows with clinical bovine mastitis (CBM) in China. A total of 220 cows with clinical mastitis, which has swollen mammary udder with reduced and red or gangrenous milk, were selected from 5000 cows. The results showed 94.3% of the isolates were recognized as multidrug resistant. The isolates (30.5%) were positive for the class I integrase gene along with seven gene cassettes that were accountable for resistance to trimethoprim resistance (dfrA17, dfr2d and dfrA1), aminoglycosides resistance (aadA1 and aadA5) and chloramphenicol resistance (catB3 and catB2), respectively. The bla TEM gene was present in all the isolates, and these carried the bla CTX gene. A double mutation in gyrA (i.e., Ser83Leu and Asp87Asn) was observed in all fluoroquinolone-resistant isolates. In total, nine fluoroquinolone-resistant E. coli isolates were identified with five different types of mutations in parC. In four (44.4%) isolates, Ser458Ala was present in parE, and in all nine (9/9) fluoroquinolone-resistant isolates, Pro385Ala was present in gyrB. Meanwhile, fluoroquinolone was observed as highly resistant, especially in isolates with gyrA and parC mutations. In summary, the findings of this research recognize the fluoroquinolone resistance mechanism and disclose integron prevalence and ESBLs in E. coli isolates from lactating cattle with CBM.

Genetic characterization of ESBL-producing and ciprofloxacin-resistant Escherichia coli from Belgian broilers and pigs.

The increasing number of infections caused by Escherichia coli resistant to clinically important antibiotics is a global concern for human and animal health. High overall levels of extended-spectrum beta-lactamase (ESBL)-producing and ciprofloxacin-resistant (ciproR) Escherichia coli in livestock are reported in Belgium. This cross-sectional study aimed to genotypically characterize and trace ESBL-and ciproR-E. coli of Belgian food-producing animals. A total of 798 fecal samples were collected in a stratified-random sampling design from Belgian broilers and sows. Consequently, 77 ESBL-E. coli and 84 ciproR-E. coli were sequenced using Illumina MiSeq. Minimum inhibitory concentration (MIC) for fluoroquinolones and cephalosporins were determined. Molecular in silico typing, resistance and virulence gene determination, and plasmid identification was performed. Scaffolds harboring ESBL or plasmid-mediated quinolone resistance (PMQR) genes were analyzed to detect mobile genetic elements (MGEs) and plasmid origins. Core genome allelic distances were used to determine genetic relationships among isolates. A variety of E. coli sequence types (ST) (n = 63), resistance genes and virulence profiles was detected. ST10 was the most frequently encountered ST (8.1%, n = 13). The pandemic multidrug-resistant clone ST131 was not detected. Most farms harbored more than one ESBL type, with bla CTX-M-1 (41.6% of ESBL-E. coli) being the most prevalent and bla CTX M-15 (n = 3) being the least prevalent. PMQR genes (15.5%, n = 13) played a limited role in the occurrence of ciproR-E. coli. More importantly, sequential acquisition of mutations in quinolone resistance-determining regions (QRDR) of gyrA and parC led to increasing MICs for fluoroquinolones. GyrA S83L, D87N and ParC S80I mutations were strongly associated with high-level fluoroquinolone resistance. Genetically related isolates identified within the farms or among different farms highlight transmission of resistant E. coli or the presence of a common reservoir. IncI1-I(alpha) replicon type plasmids carried different ESBL genes (bla CTX-M-1, bla CTX-M-32 and bla TEM-52C). In addition, the detection of plasmid replicons with associated insertion sequence (IS) elements and ESBL/PMQR genes in different farms and among several STs (e.g., IncI1-I(alpha)/IncX3) underline that plasmid transmission could be another important contributor to transmission of resistance in these farms. Our findings reveal a multifaceted narrative of transmission pathways. These findings could be relevant in understanding and battling the problem of antibiotic resistance in farms.

Intestinal colonization with ESBL-producing Klebsiella pneumoniae in healthy rural villager: A genomic surveillance study in China, 2015-2017.

The worldwide emergence and diffusion of extended-spectrum β-lactamase-K. pneumoniae (ESBL-KP) is of particular concern. Although ESBL-KP can inhabit the human gut asymptomatically, colonization with ESBL-KP is associated with an increased risk of ESBL-KP infection and mortality. In this study, we investigated the prevalence and characteristics of ESBL-KP in fecal samples from healthy persons in 12 villages in Shandong Province, China. Screening for ESBL-KP in fecal samples was performed by selective cultivation. The bacterial species were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rDNA sequence analysis. Minimum inhibitory concentrations (MICs) of 16 antibiotics were determined by the agar dilution method. Plasmid replicons, antimicrobial resistance genes and Sequence types (STs) of the isolates were determined by whole-genome sequencing (WGS). Genetic relatedness of ESBL-KP isolates was determined by the single nucleotide polymorphisms (SNP). The S1 nuclease-pulsed-field gel electrophoresis (S1-PFGE) was used to characterize the plasmids carried by ESBL-KP isolates. Conjugation assays was used to verify the transferability of bla CTX - M. ESBL-KP prevalence rates increased from 12.0% in 2015 to 27.5% in 2017. The experimental results showed that 97% of isolates had multi-drug resistance. Multiple ESBL resistance genotypes were commonly detected in the isolates. STs among the ESBL-KP isolates were diverse. All 69 bla CTX-M-3-positive isolates were located on plasmids, and these genes could be transferred with plasmids between different strains. Phylogenetic analysis showed the possibility of transmission among some isolates. This study obtained the drug resistance patterns, the drug resistance phenotype and molecular characteristics of fecal-derived ESBL-KP in rural communities in Shandong Province, China. We report a rapid increase in occurrence of ESBL-KP among fecal samples collected from healthy rural residents of Shandong Province from 2015 to 2017. The carriage rate of multidrug-resistant bacteria in healthy residents is increasing. Thus, a need for further monitoring and possible interventions of ESBL-KP in this region is warranted.

Characterization and Comparative Genomics Analysis of lncFII Multi-Resistance Plasmids Carrying bla CTX - M and Type1 Integrons From Escherichia coli.

This research aimed to investigate the presence and transferability of the extended-spectrum β-lactamase resistance genes to identify the genetic context of multi-drug resistant (MDR) loci in two Escherichia coli plasmids from livestock and poultry breeding environment. MICs were determined by broth microdilution. A total of 137 E. coli resistant to extended-spectrum β-lactam antibiotics were screened for the presence of the ESBL genes by PCR. Only two E. coli out of 206 strains produced carbapenemases, including strain 11011 that produced enzyme A, and strain 417957 that produced enzyme B. The genes were blaKPC and blaNDM, respectively. The plasmids containing blaCTX–M were conjugatable, and the plasmids containing carbapenem resistance gene were not conjugatable. Six extended-spectrum β-lactamase resistance genes were detected in this research, including blaTEM, blaCTX–M, blaSHV, blaOAX–1, blaKPC, and blaNDM, and the detection rates were 94.89% (130/137), 92.7% (127/137), 24.81% (34/137), 20.43% (28/137), 0.72% (1/137), and 0.72% (1/137), respectively. Two conjugative lncFII multi-resistance plasmids carrying blaCTX–M, p11011-fosA and p417957-CTXM, were sequenced and analyzed. Both conjugative plasmids were larger than 100 kb and contained three accessory modules, including MDR region. The MDR region of the two plasmids contained many antibiotic resistance genes, including blaCTX–M, mph (A), dfrA17, aadA5, sul1, etc. After transfer, both the transconjugants displayed elevated MICs of the respective antimicrobial agents. A large number of resistance genes clusters in specific regions may contribute to the MDR profile of the strains. The presence of mobile genetic elements at the boundaries can possibly facilitate transfer among Enterobacteriaceae through inter-replicon gene transfer. Our study provides beta-lactam resistance profile of bacteria, reveals the prevalence of β-lactamase resistance genes in livestock and poultry breeding environment in Zhejiang Province, and enriches the research on IncFII plasmids containing blaCTX–M.

Successful Treatment of Severe Post-craniotomy Meningitis Caused by an Escherichia coli Sequence Type 410 Strain Coharboring bla NDM - 5 and bla CTX - M - 65.

Intracranial infections caused by multidrug-resistant Gram-negative bacterium have led to considerable mortality due to extremely limited treatment options. Herein, we firstly reported a clinical carbapenem-resistant Escherichia coli isolate coharboring blaNDM–5 and blaCTX–M–65 from a patient with post-craniotomy meningitis. The carbapenem-resistant Escherichia coli strain CNEC001 belonging to Sequence Type 410 was only susceptible to amikacin and tigecycline, both of which have poor penetration through the blood-brain barrier (BBB). The blaCTX–M–65 gene was expressed on a 135,794 bp IncY plasmid. The blaNDM–5 gene was located on a genomic island region of an IncX3-type plasmid pNDM5-CNEC001. Based on the characteristics of the strain, we presented the successful treatment protocol of intravenous (IV) tigecycline and amikacin combined with intrathecal (ITH) amikacin in this study. Intracranial infection caused by Escherichia coli coharboring blaNDM–5 and blaCTX–M–65 is rare and fatal. Continuous surveillance and infection control measures for such strain need critical attention in clinical settings.

Role played by the environment in the emergence and spread of antimicrobial resistance (AMR) through the food chain.

The role of food‐producing environments in the emergence and spread of antimicrobial resistance (AMR) in EU plant‐based food production, terrestrial animals (poultry, cattle and pigs) and aquaculture was assessed. Among the various sources and transmission routes identified, fertilisers of faecal origin, irrigation and surface water for plant‐based food and water for aquaculture were considered of major importance. For terrestrial animal production, potential sources consist of feed, humans, water, air/dust, soil, wildlife, rodents, arthropods and equipment. Among those, evidence was found for introduction with feed and humans, for the other sources, the importance could not be assessed. Several ARB of highest priority for public health, such as carbapenem or extended‐spectrum cephalosporin and/or fluoroquinolone‐resistant Enterobacterales (including Salmonella enterica), fluoroquinolone‐resistant Campylobacter spp., methicillin‐resistant Staphylococcus aureus and glycopeptide‐resistant Enterococcus faecium and E. faecalis were identified. Among highest priority ARGs bla CTX ‐M, bla VIM, bla NDM, bla OXA ‐48-like, bla OXA ‐23, mcr, armA, vanA, cfr and optrA were reported. These highest priority bacteria and genes were identified in different sources, at primary and post‐harvest level, particularly faeces/manure, soil and water. For all sectors, reducing the occurrence of faecal microbial contamination of fertilisers, water, feed and the production environment and minimising persistence/recycling of ARB within animal production facilities is a priority. Proper implementation of good hygiene practices, biosecurity and food safety management systems is very important. Potential AMR‐specific interventions are in the early stages of development. Many data gaps relating to sources and relevance of transmission routes, diversity of ARB and ARGs, effectiveness of mitigation measures were identified. Representative epidemiological and attribution studies on AMR and its effective control in food production environments at EU level, linked to One Health and environmental initiatives, are urgently required.

Genomic profiling of Escherichia coli isolates from bacteraemia patients: a 3-year cohort study of isolates collected at a Sydney teaching hospital.

This study sought to assess the genetic variability of Escherichia coli isolated from bloodstream infections (BSIs) presenting at Concord Hospital, Sydney during 2013–2016. Whole-genome sequencing was used to characterize 81 E. coli isolates sourced from community-onset (CO) and hospital-onset (HO) BSIs. The cohort comprised 64 CO and 17 HO isolates, including 35 multidrug-resistant (MDR) isolates exhibiting phenotypic resistance to three or more antibiotic classes. Phylogenetic analysis identified two major ancestral clades. One was genetically diverse with 25 isolates distributed in 16 different sequence types (STs) representing phylogroups A, B1, B2, C and F, while the other comprised phylogroup B2 isolates in subclades representing the ST131, ST73 and ST95 lineages. Forty-seven isolates contained a class 1 integron, of which 14 carried bla CTX -M-gene. Isolates with a class 1 integron carried more antibiotic resistance genes than isolates without an integron and, in most instances, resistance genes were localized within complex resistance loci (CRL). Resistance to fluoroquinolones could be attributed to point mutations in chromosomal parC and gyrB genes and, in addition, two isolates carried a plasmid-associated qnrB4 gene. Co-resistance to fluoroquinolone and broad-spectrum beta-lactam antibiotics was associated with ST131 (HO and CO), ST38 (HO), ST393 (CO), ST2003 (CO) and ST8196 (CO and HO), a novel ST identified in this study. Notably, 10/81 (12.3 %) isolates with ST95 (5 isolates), ST131 (2 isolates), ST88 (2 isolates) and a ST540 likely carry IncFII–IncFIB plasmid replicons with a full spectrum of virulence genes consistent with the carriage of ColV-like plasmids. Our data indicate that IncF plasmids play an important role in shaping virulence and resistance gene carriage in BSI E. coli in Australia.

Antimicrobial Resistance and Virulence Characterization of E. Coli Isolated from Subclinical Mastitic Sheep and Goats

Mastitis is one of the most serious healthy and economic problems in all dairy sheep and goat flocks. Examination of 200 milk samples collected from apparently healthy sheep and goats using California mastitis test (CMT) showed that 94 (47%) were CMT positive. Standard methods for isolation and identification of E. coli could identify 19 strains. Five different serogroups were successfully identified among 19 E. coli strains, the serogroups were O1 (21.1%), O26 (21.1%), O114 (15.8%), O148 (15.8%) and finally O125 (10.4%), in addition to 3 untypable strains. The antimicrobial susceptibility results for erythromycin and cefoxtin revealed all E. coli isolates were resistant to erythromycin (100%) followed by high frequencies of resistance observed to cefoxtin 18 isolates (94.7%). Phylogenetic grouping of E. coli by triplex PCR using two genes (chuA and yjaA) and an anonymous DNA fragment tspE4C2 indicated that 5/6 were B2 group and 1/6 was A group. Detection of virulence genes of 6 E. coli. isolates showed that 2/6 harbored eaeA gene and none of 6 isolates harbored CFA/I gene. While, the mph A erythromycin resistance gene were present in 4/6.but 2/6 isolates harbored bla CTX cefoxitin resistance gene.

Molecular Characterisation of ESBL producer E. coli

Background: Antibiotic resistance emerged as clinical problem challenge the effective treatment of infections. Virulence factor may play an important role in the influence of antimicrobial resistance.
 Objective: To determine the frequency of resistance gene in E. coli clinical isolates from women with urinary tract infection.
 Materials and Methods: Fifteen E.coli clinical isolates were tested by PCR to determine their molecular characterization.
 Results: The bla CTX –M gene was not detected in 6.7% out of the tested 15 E. coli clinical isolates from women with urinary tract infection. However, bla OXA gene was detected in all E. coli tested clinical isolates from pregnant women, female student and diabetic women with urinary tract infection. While bla TEM gene and bla SHV gene were not detected in 33.3% and 40% out of the tested E. coli clinical isolates respectively.
 Conclusions: Four types of ESBL genes were detected, and shows new trend of distribution, which indicated the predominance of OXA and CTX-M genes.

Molecular Characterization of blaTEM and blaCTX-M in ESBLs producing Escherichia coli and Salmonella spp. in Poultry farm and Klebsiella pneumoniae and Proteus spp. in Klang River in Malaysia

Event Abstract Back to Event Molecular Characterization of blaTEM and blaCTX-M in ESBLs producing Escherichia coli and Salmonella spp. in Poultry farm and Klebsiella pneumoniae and Proteus spp. in Klang River in Malaysia Nagaraja Suryadevara1*, Kai Boon Yong1, Sharanya Rajan1, Yoke Ing Kwan1 and Michelle Fong Ting Lim1 1 Mahsa University, Malaysia Introduction: Multidrug resistance bacteria (MDR) has emerged as a public health threat nowadays. High level of resistance to beta-lactam antibiotics among Enterobacteriaceae was conferred by Extended Spectrum Beta-Lactamase (ESBL) in the poultry farm. The waste material of the livestock could pollute the river, leading to the aquatic environment as a reservoir of antimicrobial resistance. Methods: The physiochemical properties of water samples were determined. Gram-negative microorganisms were identified using differential media and biochemical testing. Confirmed bacterial isolates were tested for multidrug resistance by using Kirby Bauer method. The ESBL strains were determined phenotypically using Combination Disc Test (CDT) and Double Disc Synergy Test (DDST). Bacterial genomic DNA was extracted from positive ESBL strains, blaTEM and blaCTX-M genes were amplified using Polymerase Chain Reaction (PCR). The amplified products were sequenced to identify the mutated genes in MDR strains. Results: Out of 88 samples collected from poultry farm, 73 (83.0%) E.coli and 59 (67.0%) Salmonella spp. were identified. Of 50 water samples from Klang River, 31 (62.0%) Klebsiella pneumoniae and 13 (26.0%) Proteus spp. were found. In total, 11 (15.1%) E.coli, 14 (23.7%) Salmonella spp., 12 (38.7%) Klebsiella pneumoniae, and 7 (53.8%) Proteus spp. were MDR strains. From there, 8 (72.7%) E.coli, 7 (50.0%) Salmonella spp., 5 (16.1%) Klebsiella pneumoniae and 5 (38.5%) Proteus spp. were ESBL positive strains. The genes blaTEM and blaCTX-M were seen exhibited in 3 (42.9%) and 7 (87.5%) E.coli , 1(14.3%) and 5(71.4%) Salmonella spp., 1 (20.0%) and 4(80.0%) Klebsiella pneumoniae and 1 (20.0%) and 4 (80.0%) Proteus spp., respectively. Conclusion: Classic blaTEM and blaCTX-M genes were present in E.coli and Salmonella spp. from poultry samples; and Klebsiella pneumoniae and Proteus spp. from river water samples. However, blaCTX-M gene was seen more prominent compared to blaTEM gene in the isolated ESBL strains. Acknowledgements Author would like to thank the MAHSA University Management for providing us the necessary laboratory facilities and equipment through out the research. Keywords: MDR - (multi drug resistant), ESBL - Extended-spectrum beta-lactamase, Bla TEM, bla CTX -M1, DDST, CDT Conference: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”, Putrajaya, Malaysia, 3 Dec - 5 Feb, 2019. Presentation Type: Oral Presentation Topic: Miscellaneous Citation: Suryadevara N, Yong K, Rajan S, Kwan Y and Ting Lim M (2019). Molecular Characterization of blaTEM and blaCTX-M in ESBLs producing Escherichia coli and Salmonella spp. in Poultry farm and Klebsiella pneumoniae and Proteus spp. in Klang River in Malaysia. Front. Pharmacol. Conference Abstract: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”. doi: 10.3389/conf.fphar.2018.63.00091 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 22 Oct 2018; Published Online: 17 Jan 2019. * Correspondence: Dr. Nagaraja Suryadevara, Mahsa University, Kuala Lumpur, Malaysia, nagaraja@mahsa.edu.my Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Nagaraja Suryadevara Kai Boon Yong Sharanya Rajan Yoke Ing Kwan Michelle Fong Ting Lim Google Nagaraja Suryadevara Kai Boon Yong Sharanya Rajan Yoke Ing Kwan Michelle Fong Ting Lim Google Scholar Nagaraja Suryadevara Kai Boon Yong Sharanya Rajan Yoke Ing Kwan Michelle Fong Ting Lim PubMed Nagaraja Suryadevara Kai Boon Yong Sharanya Rajan Yoke Ing Kwan Michelle Fong Ting Lim Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. 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Detection and identification of the extended- spectrum β-lactamases (bla SHV and bla CTX –M) Klebsiella pneumonia by PCR technique

Detection and identification of the extended- spectrum β-lactamases (bla SHV and bla CTX –M) Klebsiella pneumonia by PCR technique

Detection of ctx-M gene in ESBL-producing E. coli strains isolated from urinary tract infection in Semnan, Iran.

IntroductionThe incidence of urinary tract infections caused by Extended-Spectrum Beta Lactamase (ESBL) producing Escherichia coli (E. coli) strains due to long term and overuse of broad-spectrum cephalosporine is on the rise. CTX beta-lactamase type, a broad-spectrum beta-lactamase, has been expanding in many countries. The ctx gene is harbored on a plasmid that is spread between Enterobacteriaceae family, especially in E. coli. The aim of this study was to determine the pattern of antimicrobial resistance and investigate the prevalent ESBL phenotype and the ctx-M gene in E. coli isolated from patients with urinary tract infections (UTI) in Semnan.MethodsA cross sectional study was performed on 109 strains of E. coli isolated from the urine culture of patient suffering from a UTI referred to Shafa hospital (Semnan, Iran) during March–July 2015. Antimicrobial susceptibility testing was applied and the prevalence of the ESBL phenotype was confirmed using combination disk. PCR methods were completed for amplification of the bla ctx gene. Data were analyzed using SPSS version 18 software.ResultsOne hundred ninety samples (4.16%) were identified as E. coli. Twenty one (26.6%) of E. coli were ESBL positive and 73.4% were ESBL negative. There was 100% susceptibility to imipeneme. Twenty (68.97%) out of 29 isolates were positive for the ctx-M gene, as detected by PCR.ConclusionIn urinary tract infections, antibiotic treatment was experimental and detailed information regarding the sensitivity of bacteria in the area can be useful to achieve the best treatment.

Outbreak of Extended-Spectrum Beta-Lactamase Producing Enterobacter cloacae with High MICs of Quaternary Ammonium Compounds in a Hematology Ward Associated with Contaminated Sinks.

Objective: To investigate an outbreak of extended-spectrum beta-lactamase (ESBL) producing Enterobacter cloacae that occurred in the Hematology ward (24-bed unit) of the François Mitterrand University Hospital (Dijon, France) between January 2011 and December 2013. The outbreak involved 43 patients (10 infected and 33 colonized).Design: We performed environmental analysis to detect multiresistant E. cloacae for comparison with clinical isolates (genotyping by pulsed-field gel electrophoresis and MLST as well as ESBL-typing) and determined the MICs of the quaternary ammonium compounds (QACs) alkyldimethylbenzylammonium chloride (ADBAC) and didecyldimethylammonium chloride (DDAC). A bleach-based cleaning-disinfection program was implemented in December 2012 after mechanical removal of the biofilm in all sinks.Results: We have detected 17 ESBL-producing E. cloacae in patients sink drains, shower drains and medical sink drains. Sequencing of the bla genes performed on 60 strains recovered from patients and environment (n = 43 clinical and n = 17 environmental) revealed that bla CTX−M15 was predominant (37 isolates) followed by bla CTX−M9 plus bla SHV−12 (20 isolates). We observed a great diversity among the isolates: 14 pulsotypes (11 STs) in clinical isolates and 9 pulsotypes (7 STs) in environmental isolates. Six pulsotypes were identical between clinical and environmental isolates. MICs of the quaternary ammonium compounds widely used for disinfection were very high in clinical and environmental isolates. Immediately after the implementation of the disinfection program we noticed a substantial fall in cases number. Our findings demonstrate the role of drains as important reservoir of ESBL-producing E. cloacae and highlight the necessity to settle drains accessible to achieve correct cleaning as well as to use disinfectant with proved activity against nosocomial pathogens.

Risk factors for KPC-producing Klebsiella pneumoniae: watch out for surgery.

This study describes the molecular characteristics and risk factors associated with carbapenem-resistant Klebsiella pneumoniae strains. Risk factors associated with KPC-producing K. pneumoniae strains were investigated in this case-control study from May 2011 to May 2013. Bacterial identification was performed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility was determined by broth microdilution. Carbapenemase production was assessed by both modified Hodge test (MHT) and ertapenem hydrolysis using MALDI-TOF MS. The presence of β-lactamase-encoding genes was evaluated by PCR and DNA sequencing. Alterations in genes encoding K. pneumoniae outer membrane proteins were analysed by PCR and DNA sequencing as well as SDS-PAGE. Genetic relatedness among strains was determined by pulsed-field gel electrophoresis. This study included 94 patients. Longer hospitalisation, mechanical ventilation, catheters, and previous surgery were associated with KPC-producing K. pneumoniae. Sixty-eight strains showed resistance to carbapenems. Carbapenemase production was detected by MHT in 67 K. pneumoniae strains and by MALDI-TOF MS in 57. The presence of the blaKPC-2 gene was identified in 57 strains. The blaKPC-2 gene was not found in 11 carbapenem-resistant K. pneumoniae; instead, the blaCTX-M-1-like, blaCTX-M-2-like, blaCTX-M-8 like, blaCTX-M-14-like and blaSHV- like genes associated with OmpK35 and OmpK36 alterations were observed. Thirty-three KPC-producing K. pneumoniae strains were clonally related, and patients infected with these strains had a higher mortality rate (78.78 %). Our results show that KPC-producing K. pneumoniae was associated with several healthcare-related risk factors, including recent surgery.

Detection of Extended Spectrum Beta-Lactamases Resistance Genes among Bacteria Isolated from Selected Drinking Water Distribution Channels in Southwestern Nigeria.

Extended Spectrum Beta-Lactamases (ESBL) provide high level resistance to beta-lactam antibiotics among bacteria. In this study, previously described multidrug resistant bacteria from raw, treated, and municipal taps of DWDS from selected dams in southwestern Nigeria were assessed for the presence of ESBL resistance genes which include bla TEM, bla SHV, and bla CTX by PCR amplification. A total of 164 bacteria spread across treated (33), raw (66), and municipal taps (68), belonging to α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, Flavobacteriia, Bacilli, and Actinobacteria group, were selected for this study. Among these bacteria, the most commonly observed resistance was for ampicillin and amoxicillin/clavulanic acid (61 isolates). Sixty-one isolates carried at least one of the targeted ESBL genes with bla TEM being the most abundant (50/61) and bla CTX being detected least (3/61). Klebsiella was the most frequently identified genus (18.03%) to harbour ESBL gene followed by Proteus (14.75%). Moreover, combinations of two ESBL genes, bla SHV + bla TEM or bla CTX + bla TEM, were observed in 11 and 1 isolate, respectively. In conclusion, classic bla TEM ESBL gene was present in multiple bacterial strains that were isolated from DWDS sources in Nigeria. These environments may serve as foci exchange of genetic traits in a diversity of Gram-negative bacteria.

Nosocomial Intravascular Catheter Infections with Extended-spectrum Beta-lactamase-producing Escherichia coli in Calves after Strain Introduction from a Commercial Herd.

SummaryAn outbreak of intravascular catheter‐related infections by extended‐spectrum β‐lactamase (ESBL)‐producing Escherichia coli in calves in an animal teaching hospital is reported. Pulsed‐field gel electrophoresis was used for strain typing to determine the origin and dissemination of these strains. All 19 strains harboured the bla CTX ‐M‐14, and six strains also overexpressed their chromosomal AmpC gene. Evidence on the introduction of the strain from a beef herd, experiencing neonatal diarrhoea and increased mortality, to the clinic through admission of diarrhoeic calves was provided. Strains isolated from phlebitis cases from other herds up to 5 months later showed a high similarity with the initial strain, suggesting that the strain had become nosocomial. The catheter infections with ESBL/AmpC‐producing E. coli resulted in a prolonged hospitalization, increased anti‐microbial use and mortality. This report points towards the potential dangers of the emergence of ESBL/AmpC‐producing bacteria in susceptible food animals and warns farmers and veterinarians for the facility by which they are introduced into another environment.

Characterization of AmpC, CTX-M and MBLs types of β-lactamases in clinical isolates of Klebsiella pneumoniae and Escherichia coli producing Extended Spectrum β-lactamases in Kerman, Iran.

Background:Extended spectrum β-lactamases (ESBLs) and AmpC β-lactamases enzyme are major sources of resistance to β-lactam antibiotics especially in Enterobacteriaceae such as Escherichia coli and Klebsiella pneumoniae. Increasing frequency of the co-existence of ESBLs with AmpC-β-lactamases in bacteria is a serious threat for treating bacterial infections.Objectives:The aim of this study was to determine the presence of AmpC and CTX-M types of β-lactamases in clinical isolates of E. coli and K. pneumoniae producing ESBLs.Materials and Methods:Resistance to different antibiotics was determined using the standard disk diffusion method. ESBLs, MBLs and AmpC-β-lactamases were detected by the combination double disk test (CDDT) method and polymerase chain reaction (PCR) was used to determine blaCTX-M genes in the ESBLs and AmpC positive isolates.Results:The prevalence of ESBLs and AmpC-β-lactamase producer isolates was 181 (43.8%) and 133 (37.2%), respectively. The prevalence of blaCTX-M among isolates was 61 (14.7%).Conclusions:Outbreak of isolates co-expressing AmpC-β-lactamases and ESBLs can cause serious problems in the future, regarding the treatment of infections caused by these common enteric pathogens.

Molecular characterization of extended spectrum β-lactamase (ESBL) producing Shigella species isolated from patients with bacillary dysentery in Iraq

Background: Extended-spectrum β-lactamases (ESBLs), including cefotaximases (CTX-M), mediate resistance to extended spectrum cephalosporins and significantly compromise the treatment tools for Shigellosis.
 Objective: To determine the ESBLs production by Shigella spp. and its role in the resistance to third generation cephalosporins and to determine the occurrence of plasmid- borne blaCTX genes in ESBLS Shigella isolates by Multiplex PCR.
 Methods: Susceptibility of 59 clinical Shigella isolates was tested by disk diffusion method to six antimicrobial agents. Presence of ESBLs was established by the combination disk method. Minimum inhibitory concentration of β-lactams was determined by agar dilution method for resistant isolates, and then ESBL producers were subjected to plasmid extraction and PCR experiments.
 Results: Overall isolates had high rate of resistance to Ampicillin (84.7%), Tetracycline (84.7%), Co-trimoxazole(72.9%) and Cefotaxime(69.5%). Moderate to Ceftriaxone (52.5%) and low rate of resistance to Ceftazidime(30.5%). The MIC value of resistant isolates of S. sonnei and S. flexneri for CTX and CRO ranged from (64-512 μg/ml) for both, and (32-256 μg/ml) for CAZ, whereas S. dysenteriae exhibit only high level resistance MIC (256 μg/ml) for CTX, low level resistance (64 μg/ml) for CRO and complete susceptibility to CAZ. 31 of 41 (75.6 %) of Shigella spp. were β-lactamase producers, of these (82.6%) were S. flexneri, (68.8%) S. sonnei, and one S. dysenteriae isolate. The results of PCR amplification of bla CTX gene groups showed that blaCTX-M genes were identified in (74.19%) ESBLs isolates distributed as 14(45.16%) S.flexneri isolates, 9(29.03%) S. sonnei, while no gene was detected in ESBLs S. dysenteriae isolate. The prevalence of bla CTX-M I, bla CTX-M II (TOHO 1) and blaCTX-M III, were ( 54.8%, 16.1% and 3.2% ) respectively. Non of the isolates carried more than one type.
 Conclusion: The occurrence of plasmid- borne blaCTX genes in ESBLS Shigella isolates are increasing in Iraq with co-resistance to some other classes of antibiotics