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Abstract Background Uropathogenic Escherichia coli (UPEC) is the main etiological agent behind community-acquired and hospital-acquired urinary tract infections (UTIs), which are among the most prevalent human infections. The management of UPEC infections is becoming increasingly difficult owing to multi-drug resistance, biofilm formation, and the possession of an extensive virulence arsenal. This study aims to characterize UPEC isolates in Tanta, Egypt, with regard to their antimicrobial resistance, phylogenetic profile, biofilm formation, and virulence, as well as the potential associations among these factors. Methods One hundred UPEC isolates were obtained from UTI patients in Tanta, Egypt. Antimicrobial susceptibility was assessed using the Kirby-Bauer method. Extended-spectrum β-lactamases (ESBLs) production was screened using the double disk synergy test and confirmed with PCR. Biofilm formation was evaluated using the microtiter-plate assay and microscopy-based techniques. The phylogenetic groups of the isolates were determined. The hemolytic activity, motility, siderophore production, and serum resistance of the isolates were also evaluated. The clonal relatedness of the isolates was assessed using ERIC-PCR. Results Isolates displayed elevated resistance to cephalosporins (90–43%), sulfamethoxazole-trimethoprim (63%), and ciprofloxacin (53%). Ninety percent of the isolates were multidrug-resistant (MDR)/ extensively drug-resistant (XDR) and 67% produced ESBLs. Notably, there was an inverse correlation between biofilm formation and antimicrobial resistance, and 31%, 29%, 32%, and 8% of the isolates were strong, moderate, weak, and non-biofilm producers, respectively. Beta-hemolysis, motility, siderophore production, and serum resistance were detected in 64%, 84%, 65%, and 11% of the isolates, respectively. Siderophore production was correlated to resistance to multiple antibiotics, while hemolysis was more prevalent in susceptible isolates and associated with stronger biofilms. Phylogroups B2 and D predominated, with lower resistance and stronger biofilms in group B2. ERIC-PCR revealed considerable diversity among the isolates. Conclusion This research highlights the dissemination of resistance in UPEC in Tanta, Egypt. The evident correlation between biofilm and resistance suggests a resistance cost on bacterial cells; and that isolates with lower resistance may rely on biofilms to enhance their survival. This emphasizes the importance of considering biofilm formation ability during the treatment of UPEC infections to avoid therapeutic failure and/or infection recurrence.

Objective: To determine the distribution, phenotypic and genetic background of extended spectrum β-lactamases (ESBL)-producing Klebsiella (K.) pneumoniae clinical isolates associated with K1 and K2 serotypes in two selected hospitals in Malaysia. Methods: A total of 192 K. pneumoniae isolates were collected and subjected to antibiotic susceptibility, hypermucoviscosity test and multiplex PCR to detect the presence of K1- and K2- serotype associated genes. Multilocus sequence typing (MLST) was performed on ESBL-producing K. pneumoniae isolates presented with K1 and K2 serotypes, followed by phylogenetic analysis. Results: A total of 87 out of 192 (45.3%) of the K. pneumoniae isolates collected were ESBL producers. However, only 8.3% (16/192) and 10.9% (21/192) of the total isolates were detected to carry K1- and K2-serotype associated genes, respectively. Statistical analysis showed that K1 and K2 capsular serotypes were not significantly associated with ESBL phenotype (P=0.196). However, they were significantly associated with hypervirulent, as demonstrated by the positive string test (P

Background: Uropathogenic Escherichia coli (UPEC) is the main etiological agent behind community-acquired and hospital-acquired urinary tract infections (UTIs), which are among the most prevalent human infections. The management of UPEC infections is becoming increasingly difficult owing to multi-drug resistance, biofilm formation, and the possession of an extensive virulence arsenal. This study aims to characterize UPEC isolates in Tanta, Egypt, with regard to their antimicrobial resistance, phylogenetic profile, biofilm formation, and virulence, as well as the potential associations among these factors. Methods: One hundred UPEC isolates were obtained from UTI patients in Tanta, Egypt. Antimicrobial susceptibility was assessed using the Kirby-Bauer method. Extended-spectrum β-lactamases (ESBLs) production was screened using the double disk synergy test and confirmed with PCR. Biofilm formation was evaluated using the microtiter-plate assay and microscopy-based techniques. The phylogenetic groups of the isolates were determined. The hemolytic activity, motility, siderophore production, and serum resistance of the isolates were also evaluated. The clonal relatedness of the isolates was assessed using ERIC-PCR. Results: Isolates displayed elevated resistance to cephalosporins (90–43%), sulfamethoxazole-trimethoprim (63%), and ciprofloxacin (53%). Ninety percent of the isolates were multidrug-resistant (MDR)/ extensively drug-resistant (XDR) and 67% produced ESBLs. Notably, there was an inverse correlation between biofilm formation and antimicrobial resistance, and 31%, 29%, 32%, and 8% of the isolates were strong, moderate, weak, and non-biofilm producers, respectively. Beta-hemolysis, motility, siderophore production, and serum resistance were detected in 64%, 84%, 65%, and 11% of the isolates, respectively. Siderophore production was correlated to resistance to multiple antibiotics, while hemolysis was more prevalent in susceptible isolates and associated with stronger biofilms. Phylogroups B2 and D predominated, with lower resistance and stronger biofilms in group B2. ERIC-PCR revealed considerable diversity among the isolates. Conclusion: This research highlights the dissemination of resistance in UPEC in Tanta, Egypt. The evident correlation between biofilm and resistance suggests a resistance cost on bacterial cells; and that isolates with lower resistance may rely on biofilms to enhance their survival. This emphasizes the importance of considering biofilm formation ability during the treatment of UPEC infections to avoid therapeutic failure and/or infection recurrence. [ABSTRACT FROM AUTHOR]

The occurrence of β-lactamases and sulfonamide resistance genes in ESBL-producing E. coli from faecal matter of lizards was investigated. Isolation of ESBL-producing E. coli from lizard faecal matter was done on CHROMagar ESBL, and identification was done using molecular method. Disc diffusion method was used for the anti-biotic susceptibility testing and detection of β-lactamases and sulfonamide resistance genes was done using PCR. Six ESBL-producing E. coli isolates were obtained. All the isolates obtained were multidrug resistant, showing a high level of resistance to the tested antibiotics. Five isolates carried at least one of the variants of blaCTX-M and sul2, one isolate carried sul1, while blaCMY was detected in three isolates, with two isolates carrying blaSHV and blaTEM concurrently. One isolate did not carry any of the genes. This study showed that faecal matter from lizards could be a reservoir of antibiotic resistant bacteria and resistance genes. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa producing extended spectrum beta lactamases (ESBL) is a major concern in the hospital settings. It is usually reported in Enterobacteriaceae and is less frequently observed in P. aeruginosa. There is no recommended test for ESBL detection in P.aeruginosa. Therefore, we determined the occurrence of ESBL in clinical isolates of P.aeruginosa by both phenotypic and genotypic methods. Antimicrobial susceptibility tests were done on two hundred and thirteen isolates of P. aeruginosa. Phenotypic detection of ESBL was performed using combined disk method and ESBL encoding genes such as blaVEB, blaPER, blaPSE, blaGES, blaTEM, blaSHV, blaCTX-M, blaBEL, blaOXA1, blaOXA10, blaOXA2 were studied by simplex PCR. Of the 213 isolates, 85 were identified as resistant to ceftazidime and 27/85 isolates were confirmed to be ESBL producers by phenotypic method. The presence of genes encoding ESBLs comprising of blaTEM (n=44), blaOXA-10 (n=19) isolates, blaOXA-1 (n=5), blaOXA-2 (n=3) were found. All OXA gene positive isolates exhibited the ESBL phenotype. The blaGES gene were identified in 4/85 (5%) isolates. This study shows the prevalence of ESBL among clinical isolates of P.aeruginosa and in particular, the presence of GES β lactamases.

Abstract Emergence of plasmid mediated colistin and extended spectrum β-lactamases (ESBL) resistant genes has been impacted the efficacy of colistin and β-lactams drugs like 3rd, 4th generation cephalosporin. Current study was aimed to investigate antimicrobial resistance genes (ARGs) among Escherichia coli isolates from meat producing commercial broilers in Pakistan. Two hundred (n=200) fecal samples were collected during January-2018 to August-2019. For isolation of E. coli, pink colonies on MacConkey agar were transferred to EMB agar. Metallic sheen color colonies were tested biochemically using API-20E kit. The molecular identification of E. coli (n=153) was targeted by amplification of uid gene through polymerase chain reaction (PCR) and different ARGs i.e. gentamicin, streptomycin, tetracycline, colistin, β-lactams drugs, quinolone and ampicillin followed by sequence analysis. Genotypically, followed by phenotypically of resistant ARGs of isolated PCR-confirmed E. coli (153) shoed resistant against gentamicin (aac(3)-IV), streptomycin (aadA1), tetracycline (tetA), colistine (mcr-1), ampicillin (bla-TEM) and bla-CTX-M were 86%, 88%, 86%, 88%, 83% & 77% respectively. 33/38 (86%) of the isolate was positive for quinolone resistance. Colistine (mcr-1), ESBLs (bla-TEM) and (bla-CTX-M) resistance genes were 88%, 83% and 77% respectively. About 33 isolated E. coli harbored the both mcr-1 and ESBLs genes. All of E. coli isolates were found sensitive to ceftriaxone (CTX-30) and imipenem (IMP-10). The Isolated E. coli showed single or multi clade decadency. The E. coli and ARGs sequences showed single or multi clade decadency. This is first comprehensive study from Pakistan that described the molecular evidences of ARGs and their co-existence in single isolates originated from commercial poultry. Commercial chicken (Broilers) can act as melting pot of antibiotic resistance genes for human being. It is alarming situation for surveillance of antibiotic resistance program because of more regulated prescription of antimicrobial agents in Pakistan

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Pseudomonas aeruginosa producing extended spectrum beta lactamases (ES BL) is a major concern in the hospital settings. It is usually reported in Enterobacteriaceae and is less frequently observed in P. aeruginosa. There is no recommended test for ES BL detection in P.aeruginosa. Therefore, we determined the occurrence of ES BL in clinical isolates of P.aeruginosa by both phenotypic and genotypic methods. Antimicrobial susceptibility tests were done on two hundred and thirteen isolates of P. aeruginosa. Phenotypic detection of ES BL was performed using combined disk method and ES BL encoding genes such as blaVEB, blaPER, blaPSE, blaGES, blaTEM, blaSHV, blaCTX-M, blaBEL, blaOXA1, blaOXA10, blaOXA2 were studied by simplex PCR. Of the 213 isolates, 85 were identified as resistant to ceftazidime and 27/85 isolates were confirmed to be ES BL producers by phenotypic method. The presence of genes encoding ES BLs comprising of blaTEM (n=44), blaOXA-10 (n=19) isolates, blaOXA-1 (n=5), blaOXA-2 (n=3) were found. All OXA gene positive isolates exhibited the ES BL phenotype. The blaGES gene were identified in 4/85 (5%) isolates. This study shows the prevalence of ES BL among clinical isolates of P.aeruginosa and in particular, the presence of GES ß lactamases. [ABSTRACT FROM AUTHOR]

Background:  Enterobacteriaceae are a group of aerobic and facultative anaerobic Gram-negative bacilli known to cause various infections in healthy folks and those with preexisting health conditions., Aim:  Current research focuses on analyzing the bacteriological profile of clinical isolates, examining their antimicrobial susceptibility and the spectrum of drug resistance., Materials and Methods:  The study was conducted on patients admitted to the inpatient/outpatient department at Krishna Hospital, Karad. Clinical samples from patients with suspected infections, including pus, sputum, urine, blood, and other body fluids, were examined. The 156 bacterial isolates were identified using Gram staining and biochemical tests following the standard protocol., Results:  Of the 156 isolates, Klebsiella pneumoniae  was the most common isolate, with 79 (50.6%), followed by Escherichia coli , with 52 (33.3%). The maximum resistance was demonstrated toward co-trimoxazole (96.3%), ciprofloxacin (88.7%), and ceftazidime (84.6%)., Conclusion:  During the study, the prevalence of metallo-β-lactamase (MBL), extended-spectrum β-lactamase (ESBL), and AmpC increased significantly. The study data showed the overall prevalence of MBL, ESBL, and AmpC to be 67.3%, 37.8%, and 38.4%, respectively. Further, the rate of multidrug-resistant isolates was noteworthy (92.6%). Thus, comprehending the resistance pattern and epidemiology of the organism within a specific demographic area can help create better guidelines to curtail such infections., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Institutional Ethics Committee, Krishna Institute of Medical Sciences (Deemed to be University), Karad issued approval 068/2021-2022. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Sharma et al.)

Antibiotic resistance poses a major threat to public health. More effective ways of the antibiotic prescription are needed to delay the spread of antibiotic resistance. Employment of sequencing technologies coupled with the use of trained neural network algorithms for genotype-to-phenotype prediction will reduce the time needed for antibiotic susceptibility profile identification from days to hours.In this work, we have sequenced and phenotypically characterized 171 clinical isolates of Escherichia coli and Klebsiella pneumoniae from Norway and India. Based on the data, we have created neural networks to predict susceptibility for ampicillin, 3rd generation cephalosporins and carbapenems. All networks were trained on unassembled data, enabling prediction within minutes after the sequencing information becomes available. Moreover, they can be used both on Illumina and MinION generated data and do not require high genome coverage for phenotype prediction. We cross-checked our networks with previously published algorithms for genotype-to-phenotype prediction and their corresponding datasets. Besides, we also created an ensemble of networks trained on different datasets, which improved the cross-dataset prediction compared to a single network.Additionally, we have used data from direct sequencing of spiked blood cultures and found that AMR-Diag networks, coupled with MinION sequencing, can predict bacterial species, resistome, and phenotype as fast as 1–8 h from the sequencing start. To our knowledge, this is the first study for genotype-to-phenotype prediction: (1) employing a neural network method; (2) using data from more than one sequencing platform; and (3) utilizing sequence data from spiked blood cultures.

Antibiotic resistance (AR) is one of the leading and still far from solving the problems of mankind. Implementation of strategies for controling AR at different levels is a priority task, since crisis of the possibilities of creating new antibiotics is obvious. Implementation of this strategy in the medical field consists in the rational use of antibacterial agents and hygienic control of the spread of multiresistant strains. One of the ways to rationalize the use of antimicrobial agents was WHO AWaRe classification, the purpose of which is to expand the use of narrow-spectrum antibiotics and limit the misuse of reserve groups and drugs with growing resistance levels. Implementation of these tasks is impossible without microbiological studies. Laboratory diagnostics of the infectious causes has undergone significant improvement – automation, availability of routine determination of resistance markers. The review presents the main mechanisms of AR development by common pathogens and possibility of their reflection in resistance markers. An important milestone in 2020 was the Infectious Diseases Society of America (IDSA) clinical guideline for treatment of infectious caused by common multi-resistant gram-negative bacteria. In contrast to previous clinical guidelines, this makes the prescription of antibacterial drugs primarily on information about resistance markers, antibiotic susceptibility, and also on the location of infection. The purpose of the IDSA-2020 clinical guidelines is to assist clinicians in making decisions in treatment of infections caused by extended-spectrum β-lactamase or carbapenemase-producing Enterobacteriaceae bacteria and Pseudomonas feruginosa multi-drug resistant. The review presents the main points of this clinical guideline. Thus, effective treatment of infections caused by antibiotic-resistant microorganisms is possible due to contemporary microbiological methods according to evidence-based clinical guidelines. Automated microbiological research systems significantly expand the clinical possibilities of effective treatment of infections and epidemiological control of resistant strains.

Abstract Background Raoultella are Gram-negative rod-shaped aerobic bacteria which grow in water and soil. They mostly cause nosocomial infections associated with surgical procedures. This case study is the first report of a Raoultella infection in Africa. Case presentation We report a case of a surgical site infection (SSI) caused by Raoultella planticola which developed after caesarean section (CS) and surgery for secondary small bowel obstruction. The patient became febrile with neutrophilia (19,157/µL) 4 days after laparotomy and started to develop clinical signs of a SSI on the 8th day after laparotomy. The patient continued to be febrile and became critically ill despite empirical treatment with ceftriaxone and vancomycin. Raoultella species with extended antimicrobial resistance (AMR) carrying the CTX-M-9 β-lactamase was isolated from the wound discharge. Considering the antimicrobial susceptibility test, ceftriaxone was replaced by ceftazidime. The patient recovered and could be discharged on day 29 after CS. Conclusions Raoultella planticola was isolated from an infected surgical site after repeated abdominal surgery. Due to the infection the patient’s stay in the hospital was prolonged for a total of 4 weeks. It is noted that patients undergoing surgical and prolonged inpatient treatment are at risk for infections caused by Raoultella. The development of a SSI caused by Raoultella planticola with extended AMR has to be assumed to be a consequence of ineffective antibiotic utilization. The presented case advices that rare bacteria as Raoultella should be considered as potential cause of nosocomial SSI with challenging treatment due to high levels of AMR.

aimah, United Arab Emirates; 5Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Centre (Erasmus MC), Rotterdam, The Netherlands; 6Department of Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab EmiratesCorrespondence: Mushtaq A KhanDepartment of Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab EmiratesTel +971 555368100Email [email protected] Objective: The aim of this study was to retrospectively characterize E. coli and K. pneumoniae isolates obtained from neonates during a suspected NICU outbreak of infection in Ha'il, Saudi Arabia during a period of one month (April 2014). Methods: Antibiotic susceptibility patterns, molecular characterization for antibiotic-resistant genes (blaTEM, blaSHV, and blaCTX-M), and genotyping by PFGE and MLST were performed. Results: A total of 24 E. coli and 48 K. pneumoniae isolates were cultured from neonates that had been admitted to the NICU. Among E. coli, the majority of isolates (19/24) were ESBL-positive and all of these nineteen (100%) harbored the CTX-M-15 gene. A total of 15% (3/19) were co-producers of CTX-M-15 and SHV-12, and 68.4% (13/19) were co-producers of CTX-M-15 and TEM-1. Among K. pneumoniae isolates, 87.5% (42/48) were ESBL positive with 92.85% (39/42) of these isolates containing the CTX-M-15 gene. A total of 97% (38/39) of K. pneumoniae were co-producers of CTX-M-15 and SHV-12, and 88% (37/42) were positive for TEM-1. Furthermore, 85.7% (36/42) K. pneumoniae were co-producers of CTX-M-15 and TEM-1. The majority of E. coli isolates (18/19 isolates) were grouped into two genetic clusters by pulsed field gel electrophoresis (PFGE) and all the isolates were found to be ST-131 type. In contrast, K. pneumoniae (31/42) isolates belonged to a single genotypic lineage, and all (100%) isolates belonged to the ST-14 type. Conclusion: This is the first report of CTX-M-15-positive, ESBL E. coli, and K. pneumoniae isolates recovered from an outbreak in an NICU in Ha'il, Saudi Arabia. It is alarming to note the high rate of outbreak isolates with simultaneous production of CTX-M-15 and SHV-12 conferring high-level resistance to oxyimino-cephalosporins. [ABSTRACT FROM AUTHOR]

Eric S Donkor,1 Prince Z Horlortu,1 Nicholas TKD Dayie,1 Noah Obeng-Nkrumah,2 Appiah-Korang Labi31Department of Medical Microbiology, School of Biomedical and Allied Health Sciences University of Ghana, Accra, Ghana; 2Department of Medical Laboratory Science, School of Biomedical and Allied Health Sciences University of Ghana, Accra, Ghana; 3Department of Microbiology, Korle-Bu Teaching Hospital, Accra, GhanaBackground: Urinary tract infection (UTI) is one of the most common bacterial infectious diseases encountered in clinical practice, and accounts for significant morbidity and high medical costs. To reduce its public health burden, there is the need for local research data to address aspects of prevention and management of UTI. The aim of this study was to investigate community-acquired UTI among adults in Accra, Ghana, including the risk factors, etiological agents, and antibiotic resistance.Methods: This was a cross-sectional study involving 307 patients clinically diagnosed with UTI at the Korle Bu and Mamprobi polyclinics in Accra. Urine specimens were collected from the study participants and analyzed by culture, microscopy, and dipstick. The bacterial isolates were identified using standard microbiological methods and tested against a spectrum of antibiotics by the Kirby Bauer method. Multidrug resistant Enterobacteriaceae isolates were screened for Extended Spectrum β-lactamase (ESBL) production by the double disc method, and isolates that tested positive were analyzed by Polymerase Chain Reaction for ESBL genes. Demographic information and clinical history of study participants were collected.Results: Based on the criteria for laboratory confirmed UTI, 31 (10.1%) of the 307 specimens were positive and the main risk factor of UTI among the study participants was pregnancy (P=0.02, OR=2.43). The most common uropathogen isolated was Escherichia coli (48.9%), followed by Klebseilla sp. (16.1%). Prevalence of resistance was highest for Piperacillin (87.1%) and Amoxicillin+Clavulanic Acid (87.1%) and lowest for Amikacin (12.9%). Prevalence of multidrug resistance among the uropathogens was 80.1% (25) and the most common ESBL gene detected was CTX-M-15.Conclusion: Pregnant women constitute the key risk population of UTI in Accra, while Amikacin remains a suitable drug for the treatment of febrile UTI. The high prevalence of multidrug resistance among the uropathogens highlights the need for surveillance of antimicrobial resistance among these pathogens.Keywords: extended spectrum β-lactamases, multidrug resistance, urinary tract infection

Objective: to evaluate the genetic relatedness of extended-spectrum β-lactamase (ESBL) producing Escherichia coli isolated from the gut in patients with acute myeloid leukemia and lymphoma at admission and during chemotherapy cycles. Materials and methods. The prospective study (2013–2014) included 73 patients (median age 39 years) with acute myeloid leukemia (n = 25) and lymphoma (n = 48). The follow-up period lasted for 96 days. ESBL-producing E. coli isolated from the gut were included in this study. ESBL-production was confirmed by phenotypic tests, blaCTX-M and blaTEM genes were detected by polymerase chain reaction, and genotyping was performed by ERIC (Enterobacterial Repetitive Intergenic Consensus) polymerase chain reaction. Results. ESBL-producing E. coli were detected in 39 (53 %) of 73 patients: of them 12 (16 %) patients were colonized at admission and 27 (37 %) patients – during chemotherapy cycles. Gene blaCTX-M was detected in 67 % of E. coli, blaTEM – in 41 %, both genes – in 26 %. There was no genetically related ESBL-producing E. coli among 12 isolates detected at admission. Genetic relatedness was detected in 16 (59 %) of 27 isolates obtained during a hospital stay. Genetically related ESBL-producing E. coli were isolated from patients hospitalized in the same and different departments, these isolates were characterized by the presence of both identical and various determinants of resistance. Conclusion. Our data demonstrated the possibility of patient-to-patient transmission of ESBL-producing E. coli isolated from the gut during a hospital stay.

Background and Objectives: Increasing the rate of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae has given rise to a major healthcare issue in clinical settings over the past few years. Treatment of these strains is hardly effective since the plasmid encoding ESBL may also carry other resistance genes including aminoglycosides. The current study aimed to evaluate the prevalence of ESBL-producing K. pneumoniae and investigate the coexistence of Cefoxitamase-Munich (blaCTX‑M) with aminoglycoside-modifying enzyme (AME) genes, aac(3)IIa as well as aac(6′)Ib, in CTX-M-producing K. pneumoniae isolated from patients in Bushehr province, Iran. Materials and Methods: A total of 212 K. pneumoniae isolates were collected and confirmed using polymerase chain reaction (PCR) of the malate dehydrogenase gene. Isolates were screened for production of ESBL. Phenotypic confirmatory test was performed using combined disk test. The genes encoding CTX-M groups and AME genes, aac(3)IIa and aac(6′)Ib, were investigated by PCR. Results: The ESBL phenotype was detected in 56 (26.4%) K. pneumoniae isolates. Moreover, 83.9% of ESBL-producing isolates carried the genes for CTX-M type β-lactamases, which were distributed into the two genetic groups of CTX-M-1 (97.8%)- and CTX-M-2 (2.1%)-related enzymes. Notably, among K. pneumoniae isolates containing the blaCTX-M gene, 68.08% of isolates harbored AME genes. In addition, the coexistence of blaCTX-M with aac(3)-IIa and aac(6’)-Ib was observed in 46.8% of CTX-M-producing K. pneumoniae isolates. Conclusion: This study provides evidence of a high prevalence of AME genes in CTX-M- producing K. pneumoniae isolates; therefore, in the initial empirical treatment of infections caused by ESBL-KP in regions with such antibiotic resistance patterns, aminoglycoside combination therapy should be undertaken carefully.

Introduction: Nosocomial infections caused by Multidrug Resistant (MDR) Pseudomonas aeruginosa (P. aeruginosa) have become a major clinical and public health concern. Moreover, the biofilm production protects the bacteria from antibiotics and thereby makes the drugs ineffective. Aim: To find out the β-lactamases profile of antimicrobial resistance and biofilm production of P. aeruginosa isolated from different clinical specimens of patients attending a tertiary care hospital of Kolkata, West Bengal, India. Materials and Methods: A total of 394 consecutive, nonduplicate isolates of P. aeruginosa were identified from 3559 Gram negative bacilli over a period of two years from July 2016 to June 2018. Identification of the isolates and antibiotic sensitivity testing was performed by using automated method and interpreted. Extended Spectrum β-Lactamases (ESBLs), Amp-C β-lactamase (AmpC) and Metallo-β-Lactamases (MBLs) were phenotypically detected by disk synergy test and MBLencoding genes were detected by multiplex Polymerase Chain Reaction (PCR). Biofilm production was done by tissue culture plate assay. Laboratory data and test results were statistically analysed in counts and percentages using MS Excel 2010 version. Results: Out of 394 strains of P. aeruginosa 288 (73.10%) were isolated from male patients whereas 106 (26.90%) were isolated from female patients. Maximum number of cases (67.26%) were from adult populations. The resistance pattern showed 72.33% resistance to ticarcillin-clavulanic acid followed by ciprofloxacin (53.80%), levofloxacin (50.25%), gentamicin (51.52%), ceftazidime (CAZ) (45.93%), cefoperazone-sulbactam (40.1%), aztreonam (34.77%), imipenem (33.5%), piperacillin/ tazobactum (30.96%) and Meropenem (MRP) (29.18%). Out of 394 Pseudomonas spp. isolates, 204 (51.77%) were MDR. Overall, ESBLs, AmpC and carbapenemase (MBL) production was detected in 145 (36.80%), 51 (12.94%) and 49 (12.43%) isolates by phenotypic methods. By genotypic method 53.34% were carbapenemase producing and blaNDM-1 (68.75%) was the most prevalent carbapenemase gene detected followed by blaVIM (18.75%) and co-production of blaNDM-1+ blaVIM was 12.5%. Biofilm production was observed in 158 (40.10%) isolates. Conclusion: Early detection of these β-lactamases production is crucial not only for epidemiological study and effective infection control practices to limit the spread of infection but also for planning appropriate therapy according to the resistance mechanisms of the MDR strains.

Jiranun Bubpamala,1 Piyatip Khuntayaporn,1 Krit Thirapanmethee,1 Preecha Montakantikul,2 Pitak Santanirand,3 Mullika T Chomnawang1 1Department of Microbiology, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand; 2Department of Pharmacy, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand; 3Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Purpose: Extended-spectrum β-lactamases (ESBLs) have become an issue in community worldwide due to an increase in antibiotic resistance over the past decade. This study was aimed to investigate the phenotypic and genotypic characteristics of ESBL-producing Escherichia coli in Thailand. Materials and methods: In this study, all clinical isolates collected from tertiary hospitals in Thailand were identified as E. coli by biochemical tests and MALDI-TOF mass spectrometry. ESBL-producing E. coli was preliminary screened with disk diffusion method by cephalosporin disks and confirmed by the method of combination disk diffusion. Antimicrobial susceptibility test was used to determine MIC values of all ESBL-producing E. coli. For genotypic detection, a variety of ESBL genes were determined by PCR. Moreover, multilocus sequence typing (MLST) analysis was performed on internal portions of seven housekeeping genes for the diversity and phylogenetic relatedness of E. coli clonal group. Results: Of the 285 ESBL-producing E. coli, most were susceptible to carbapenems. These strains showed a high resistance rate to ciprofloxacin (85.26%). The most frequently detected gene was bla CTX-M1 group at about 71.23% followed by bla CTX-M9 group (38.95%). The bla TEM, bla PER, bla GES, bla VEB, and bla SHV genes were identified in 31.93%, 5.96%, 4.56%, 3.51%, and 0.70% of ESBL-producing isolates, respectively. The bla OXA-10 gene was detected in only one strain. ESBL-producing E. coli isolates with high antimicrobial resistance were further investigated. Among those, E. coli sequence type ST38 was mostly found, followed by ST405, ST410, and ST131. It is noteworthy that the bla CTX-M gene was mainly detected in all four ST-type E. coli clones (ST38, ST405, ST410, and ST131). Conclusion: This study provided a recent evidence of the genetic diversity of ESBL-producing E. coli in Thailand. In addition, the profile related to antimicrobial resistance pattern in this region was also demonstrated. Keywords: epidemiology, prevalence, antimicrobial resistance, MLST, ESBLs, antibiotic resistance genes

Introduction: Nosocomial infections caused by Multidrug Resistant (MDR) Pseudomonas aeruginosa (P. aeruginosa) have become a major clinical and public health concern. Moreover, the biofilm production protects the bacteria from antibiotics and thereby makes the drugs ineffective. Aim: To find out the β-lactamases profile of antimicrobial resistance and biofilm production of P. aeruginosa isolated from different clinical specimens of patients attending a tertiary care hospital of Kolkata, West Bengal, India. Materials and Methods: A total of 394 consecutive, nonduplicate isolates of P. aeruginosa were identified from 3559 Gram negative bacilli over a period of two years from July 2016 to June 2018. Identification of the isolates and antibiotic sensitivity testing was performed by using automated method and interpreted. Extended Spectrum β-Lactamases (ESBLs), Amp-C β-lactamase (AmpC) and Metallo-β-Lactamases (MBLs) were phenotypically detected by disk synergy test and MBLencoding genes were detected by multiplex Polymerase Chain Reaction (PCR). Biofilm production was done by tissue culture plate assay. Laboratory data and test results were statistically analysed in counts and percentages using MS Excel 2010 version. Results: Out of 394 strains of P. aeruginosa 288 (73.10%) were isolated from male patients whereas 106 (26.90%) were isolated from female patients. Maximum number of cases (67.26%) were from adult populations. The resistance pattern showed 72.33% resistance to ticarcillin-clavulanic acid followed by ciprofloxacin (53.80%), levofloxacin (50.25%), gentamicin (51.52%), ceftazidime (CAZ) (45.93%), cefoperazone-sulbactam (40.1%), aztreonam (34.77%), imipenem (33.5%), piperacillin/tazobactum (30.96%) and Meropenem (MRP) (29.18%). Out of 394 Pseudomonas spp isolates, 204 (51.77%) were MDR. Overall, ESBLs, AmpC and carbapenemase (MBL) production was detected in 145 (36.80%), 51 (12.94%) and 49 (12.43%) isolates by phenotypic methods. By genotypic method 53.34% were carbapenemase producing and blaNDM-1 (68.75%) was the most prevalent carbapenemase gene detected followed by blaVIM (18.75%) and co-production of blaNDM-1+ blaVIM was 12.5%. Biofilm production was observed in 158 (40.10%) isolates. Conclusion: Early detection of these ß-lactamases production is crucial not only for epidemiological study and effective infection control practices to limit the spread of infection but also for planning appropriate therapy according to the resistance mechanisms of the MDR strains. [ABSTRACT FROM AUTHOR]

Fifty samples were collected from different samples from hospitals in Baghdad city. After morphological, microscopical examination and biochemical tests were obtained on thirty of Proteus mirabilis isolates. Antibiotic susceptibility testing was performed by the disk diffusion method, which was all P.mirabilis isolates resistance to Cefotaxime with 76.6%, followed by Tobramycin and Amikacin in the rate of 66.7%, for Gentamicin 60%, for Ciprofloxacin and Ceftazidime 40%, while Low resistance was found with Norfloxacin, Amoxicillin / Clavulanic acid and Aztreonam at 33.3%, 30% and 23.3%, respectively. There are 8 types of resistance patterns for isolates of P.mirabilis with multi-drug resistance (MDR). Which observed that 24(80%) isolates were resistant to more than three antibiotics. It has been found that 11(36.7%) isolates were produced β-lactamase enzymes, while 8(26.7%) isolates were able to produce Extended-spectrum β-lactamases. [ABSTRACT FROM AUTHOR]

Citrobacter freundii, a common cause of nosocomial infections leading to diarrhea, urinary tract infection and meningitis, is increasingly becoming multidrug resistant. The current study was aimed to determine the prevalence and antibiotic susceptibility pattern of extended spectrum β-lactamases producing C. freundii clinical isolates. A total of 2950 clinical samples were collected from both hospitalized and nonhospitalized patients of Khyber Teaching Hospital (KTH), Peshawar, and processed by for isolation of C. freundii followed by phenotypic detection of β-lactamases and antimicrobial susceptibility profile. Our results indicated that a total of 130(4.40%;130/2950) samples were positive for C. freundii comprised of urine 58.46%, pus 33.85% and wounds 7.69%, respectively. More samples from females (n=70) than males (n=60) with majority (43.08%) from age group 21-40 years were found positive for C. freundii. Of the 130 isolates, 28 (21.53%) were ESBL producers comprised of 10 (35.71%) from males and 18(64.29%) from females with majority recovered from age group of 21–40 years (57.14%). Furthermore, 10(7.69%) isolates were metallo-β lactamase (MBL) producers containing 4(40%) from males and 6(60%) from females with majority from age group of 41–60 years (60%). Of the ESBL producers, 78.57%, 71.42%, 64.29%, and 42.86% isolates displayed resistance against trimethoprim-sulphamethoxazole, levofloxacin, ciprofloxacin and piperacillin-tazobactam, respectively, while, tygacil and colistin showed 100% susceptibility. On the other hands, 60%, 80%, 40% and 20% of metallo-β lactamase producers were found resistant to trimethoprim-sulphamethoxazole, levofloxacin, ciprofloxacin and piperacillintazobactam, respectively. Overall, current results show a high number of isolates resistant to commonly used drugs, and hence appropriate usage of antibiotics must be ensured to avoid further dissemination. [ABSTRACT FROM AUTHOR]

This study analyzed a prevalence of carbapenem-resistant Klebsiella pneumoniae strains obtained in the Privolzhsky Federal Medical Research Center units and their antibiotic resistance mechanisms. During the study year, the incidence of K. pneumoniae in different units was equal to that of Pseudomonas aeruginosa. The carbapenemresistant strains of K. pneumoniae were isolated in the average of 53.5% of patients in the burn units and 2.6% of patients in the purulent osteology unit. PCR testing showed that 100% of carbapenem-resistant strains had extended spectrum β-lactamase СТХ-М genes, 79.6% of isolates carried genes of ОХА-48 carbapenemase; and metallo-β-lactamase genes were not found. A whole genome sequencing detected blaSHV in all of the strains tested and a diversity of sequence types among K. pneumoniae strains, with ST395 being predominant. K. pneumoniae strains resistant to polymyxin E (colistin) were detected in all units, and their prevalence in adult patients with a burn trauma was 6.6%.

Nosocomial infections caused by Klebsiella pneumoniae are primarily characterized by a high prevalence of extended-spectrum β-lactamases (ESBL's) and a soaring pace of carbapenemase dissemination. Availability of limited antimicrobial agents as a therapeutic option for multidrug-resistant bacteria raises an alarming concern. This study aimed at the molecular characterization of multidrug-resistant K. pneumoniae clinical isolates and studied the role of efflux pumps in β-lactam resistance. Thirty-three isolates confirmed as ESBL-positive K. pneumoniae that harbored resistance genes to major classes of antibiotics. The results showed that CTX-M15 was the preeminent β-lactamase along with carbapenemases in ESBL-positive isolates. However, the efficacy of different antibiotics varied in the presence of lactamase inhibitors and efflux pump inhibitors (EPIs). Those showing increased efficacy of antibiotics with EPI were further explored for the expression of efflux pump genes and expressed a significantly different level of efflux pumps. We found that an isolate had higher expression of kpnF (SMR family) and kdeA (MATE family) pump genes relative to RND family pump genes. No mutations were observed in the genes for porins. Together, the findings suggest that β-lactamases are not the only single factor responsible for providing resistance against the existing β-lactam drugs. Resistance may increase many folds by simultaneous expression of RND family (the most prominent family in Gram-negative bacteria) and other efflux pump family. [ABSTRACT FROM AUTHOR]

Introduction: Infections of enterobacteria producing extended-spectrum ß-lactamases place a heavy burden on health systems. Little is known in osteoarticular infections, so this work studied the prevalence of these infections in a third-level hospital. Material and methods: Prevalence study in patients of a Traumatology Service during 2016, with infection criteria provided by the CDC in Atlanta, Georgia. The VITEK® 2 AST-N272 (bioMérieux) system was used for bacterial identification at the species level and for antimicrobial susceptibility tests. Results: 7.85% (n = 86) were reported with osteoarticular infections; 22.09% (n = 19) were by enterobacteria BLEEs. An average of 77.1 days of hospitalization (SD 37.7) (46-200 days); isolation of the microorganism occurred 15 days after entry. Sixteen (84.2%) patients had osteomyelitis, three (15.8%) had a prosthetic knee or hip infection. The average number of treatment days was 60 days (21-129 days). Eighteen patients (94.7%) were discharged with resolution of their infectious picture; one patient died with infection over aggregated pneumonia due to carbapenem-resistant K. pneumoniae. Discussion: The prevalence of osteoarticular infections by enterobacteria BLEEs could not be accurately calculated, but we consider it to be within what is expected, infection control measures require higher standards and there is a lack of development programs to use antimicrobials rationally to control the emergence of these pathologies. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify and quantify faecal indicator bacteria in blackwater collected from a source separation unit and determine the amount of E. coli isolates resistant to antimicrobials and their potential to produce extended spectrum β-lactamases (ESβLs) and metallo-β-lactamases (MβLs), which hydrolyse the most important antibiotics used in clinical practice. Most of the isolates were resistant to amoxicillin with clavulanic acid (36.4 %), followed by ticarcillin with clavulanic acid (22.7 %) and tetracycline (18.2 %). ESβL-producing genes blaCTX-M and blaTEM were found in three (13.6 %) and four (18.2 %) E. coli strains, respectively, while MβL genes were found in two (9.1 %). By separating at source, this pilot study clearly shows that gastrointestinal bacteria of healthy people can be an important source of antibiotic resistance released into the environment through wastewaters. One way to prevent that is to treat wastewater with a combination of TiO2, UV light, or ozone, as successful methods to remove resistant bacteria and prevent their spread in the environment. [ABSTRACT FROM AUTHOR]

Asymptomatic bacteriuria (ASB) has been consistently observed in pregnancy. However, there is a paucity of data on the prevalence and characteristics of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in ASB in pregnant women. Therefore, we sought to investigate ESBL-producing and multidrug-resistant Enterobacteriaceae in antenatal women with ASB. Urine samples were collected from 310 asymptomatic pregnant women attending primary antenatal clinics and screened for significant bacteriuria. Isolates of Enterobacteriaceae were phenotypically tested for their ESBL production. ESBL genes (CTX-M, TEM, and SHV genes) were then amplified by polymerase chain reaction (PCR). Multiplex PCRs were used to perform phylogenetic typing of ESBL-producing Escherichia coli isolates and to examine the commonality of sequence type 131 (ST131)-O25b and ST131-O16. A total of 103 (33.2%) pregnant women were positive for significant bacteriuria (80 Enterobacteriaceae). Of these isolates, 32.5% (n = 26) were ESBL producers and had a higher rate of multidrug resistance than non-ESBL producers. Genotypic characterization of ESBL-producing isolates showed that 84.6% had the blaCTX-M gene (blaCTX-M-15 = 77.3%; blaCTX-M-9 = 18.2%). None of the isolates were of the TEM or SHV type. Half of the ESBL-producing E. coli isolates were of the phylogroup B2, and 4 (20%) isolates were of the ST131-O16 clonal subgroup. This study is the first in Egypt to provide evidence for the high prevalence of ESBL-producing Enterobacteriaceae in pregnant women with ASB. It also represents an important step toward genotypic characterization of this resistant form of bacteria, which may be useful for future antimicrobial studies. [ABSTRACT FROM AUTHOR]

Приведены данные проспективного исследования чувствительности энтеробактерий, выделенных в кардиохирургическом стационаре за 20112012 гг. Изучено 124 штамма энтеробактерий, из них доля БЛРС-продуцентов СТХ-М-типа составила 62,1%. Отмечено, что от 76,6 до 100% штаммов энтеробактерий были нечувствительны к цефалоспоринам IIIIV поколения, от 62,0 до 72,7% к ингибиторзащищенным -лактамным препаратам и 70,1% к фторхинолонам, при этом сохранялась высокая чувствительность к карбапенемам (к эртапенему 90,9%, имипенему и меропенему 94,8%), умеренная к аминогликозидам (амикацину 77,9%, нетилмицину 72,7%). Снижение чувствительности к карбапенемам обусловлено появлением штаммов K. pneumoniae с МПК эртапенема от 2 до 16 мкг/мл, меропенема 48 мкг/мл и с МПК имипенема 4 мкг/мл.

Aim: The present study was conducted to isolate and characterize the extended spectrum β-lactamases (ESBLs) producing enteric bacteria in human beings in Mizoram, India. Materials and Methods: Fecal samples were collected from human beings with or without the history of diarrhea from different hospitals of Mizoram. Samples were processed for isolation and identification of Escherichia coli, Salmonella and Klebsiella pneumoniae. All the isolates were subjected to antibiotic sensitivity assays. Phenotypically, ESBLs production ability was determined by double discs synergy test (DDST) method. ESBLs producing isolates were subjected to polymerase chain reaction (PCR) for detection of ESBLs genes. Plasmids were cured by acridine orange. Transfer of resistance from a donor to recipient strains was done by in vitro horizontal method. Results: A total of 414 enteric bacteria were isolated from 180 fecal samples (113 were from diarrheic patients and 67 were from non-diarrheic patients), of which 333 (80.44%), 52 (12.56%), and 29 (7.00%) were E. coli, K. pneumoniae and Salmonella spp., respectively. Double discs synergy test (DDST) exhibited 72 (21.62%) E. coli, 12 (23.08%) K. pneumoniae and 4 (13.79%) Salmonella spp. were ESBLs producers. Altogether, 24 (13.04%) isolates were found to be positive for at least one resistance genes under this study. A total of 36 (8.70%) E. coli, 4 (0.97%) K. pneumoniae and 2 (0.48%) Salmonella spp. were found to be positive for blaCTX-M-1 gene by PCR. Similarly, 5 (1.21%) E. coli and 4 (0.97%) K. pneumoniae isolates were found to be positive for blaSHV gene. A total of 3 (0.72%) K. pneumoniae isolates were recorded as positive for both blaCTX-M-1 and blaSHV genes. All the isolates were carrying plasmids ranging between 0.9 kb and ~30 kb. The resistance plasmid could not be transferred to a recipient by in vitro horizontal gene transfer method. Conclusion: ESBLs producing enteric bacteria are circulating in human population in North Eastern Region of India. Indiscriminate use of antibiotics should be avoided to control the menace of multidrug resistance bacteria in the environment, animals, and human beings.

Resistance of Gram-negative bacteria to the most widely used antibiotics, particularly β-lactams, is now considered as major public health problem. The main resistance mechanisms to β-lactams in Enterobacterales are the production of extended spectrum β-lactamases (ESBL) or carbapenemases, which hydrolyze virtually all β-lactams. However, a substantial proportion of carbapenem-resistant Gram-negative bacilli do not produce carbapenemase but combine overproduction of a cephalosporinase and/or ESBL with very low penem hydrolysis and reduced outer membrane permeability. The arrival of new antibacterial agents active on some of these multidrug-resistant strains, such as new β-lactam inhibitors, has marked a turning point in treatment and represents real progress. In-depth knowledge of resistance mechanisms is crucial to the choice of the most effective molecule, and their prescription requires close collaboration between microbiologists, infectious disease specialists and intensive care physicians. While these compounds are significantly more active against resistant strains than those previously available, their spectrum of activity does not cover all resistance mechanisms in Gram-negatives, nor in other bacterial species potentially involved in polymicrobial infections. The use of these new compounds does not alter antibiotic regimens in terms of duration and indication of combined antibiotic therapy, which remain very limited., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Introduction: Infection with Extended spectrum β-lactamases (ESBLs) producing bacteria is considered as serious health problem worldwide. The aim of this cross-sectional study was to investigate the prevalence of ESBL producing Escherichia coli in hospitalized patients and the risk factors contributed for its nosocomial infections in addition to the antibiotics susceptibility patterns of isolates from 130 inpatients collected in Al Thawra General Hospital and Al-Kuwait University Hospital in Sana'a city. Methodology: Antibiotic susceptibility testing and confirmation of ESBL production were performed according to the Clinical and Laboratory Standards Institute guidelines. Results: Out of 130 E. coli isolates, 44 (33.8%) were ESBLs producers, the majority of ESBLs producers were in wound exudates samples (52.2%). The highest significant rates were among the elderly, patients with previous hospitalization, patients who have stayed in hospital more than 22 days, patients who have taken third generation cephalosporins as treatment and diabetic patients. All ESBL-producing isolates were resistant to amoxicillin, trimethoprim-sulfamethoxazole and the third generation cephalosporins (100%). Resistance to other antimicrobial agents among these isolates was: amoxicillin-clavulanic acid (90.9%), nalidixic acid (95.5%), ciprofloxacin (90.9%), ofloxacin (88.6%) and tetracycline (54.5%). The most effective antibiotics in vitro for both types of isolates (ESBL producing and non ESBL producing E. coli) were Imipenem (100%), Amikacin (75%) and (93.0%), respectively, and Pipracillin-tazobactam (68.2%) and (88.4%), respectively. Conclusion: ESBLs detection tests must be performed as routine work in all hospitals and laboratories. Furthermore, a strict adherence of infection control policies and procedures with continuous antibiotics resistance surveillance are important to prevent nosocomial infections. [ABSTRACT FROM AUTHOR]

Blood stream infections are serious conditions associated with high morbi-mortality. In this study, the new Sepsis Flow Chip (SFC) assay for identification of Gram-negative bacteria and their antimicrobial resistance genes was evaluated in positive blood cultures (BCs). SFC is a microarray with a broad panel comprising the most frequent causative agents of sepsis and antimicrobial resistance genes associated with them. A total of 100 prospective BCs, positive for Gram-negative bacilli, were assessed in the routine of the clinical microbiology laboratory and also applying the SFC assay. Moreover, 19 BCs spiked with well-characterized enterobacterial isolates, harboring antimicrobial resistance genes, were analyzed by the latter. Among the monomicrobial BCs (90), the concordance between SFC identification and the reference method was 94.4%; however, it achieved 100% when SFC was combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry after 4-h incubation. Regarding polymicrobial BCs (10), 15 out of the 22 bacteria present (68.2%) were correctly identified, including all contained in 50% of the cultures. With regard to antimicrobial resistance genes, 98.8%, 98.9%, and 99% concordance was obtained for bla CTX-M , bla OXA-48 , and bla VIM , respectively, in comparison with polymerase chain reaction amplification. SFC assay gives results in only 4 h and showed a high concordance rate with the reference method. Although further evaluation studies are necessary, SFC assay implementation, together with antimicrobial stewardship programs, could contribute to improve the therapeutic approaches and to reduce the morbi-mortality, length of hospital stay, and healthcare-associated costs in patients with sepsis. [ABSTRACT FROM AUTHOR]

The in vitro activity of amikacin, gentamicin, kanamycin, tobramycin, neomycin, and netilmicin against 420 Escherichia coli producing extended spectrum β-lactamases (Ec-ESBLs) and 139 Klebsiella pneumoniae producing extended spectrum β-lactamase (Kp-ESBL) collected in two multicenter studies performed in Spain in 2000 and 2006 was determined. The presence of genes encoding aminoglycoside-modifying enzymes (AMEs) and 16S ribosomal RNA (rRNA) methylases [aac(3)-Ia, aac(3)-IIa, aac(3)-IVa, aac(6′)-Ib, ant(2")-Ia, ant(4′)-IIa, aph(3′)-Ia, aph(3′)-IIa, armA, rmtB, and rmtC] was also investigated. The resistance to (one or more) aminoglycosides was significantly higher in Kp-ESBL (104/139, 74.8%) than in Ec-ESBL (171/420, 40.7%; p < 0.0001). The lowest resistance rates for both species in the two studies were observed for amikacin. The prevalence of AME genes was significantly different in Ec-ESBL (161/420, 38.3%) than in Kp-ESBL (115/139, 82.7%; p < 0.0001). The most prevalent AME genes in Ec-ESBL and Kp-ESBL were aac(6′)-Ib (16.2% and 44.6%) and aac(3)-IIa (14.7% and 43.1%), respectively. The expected phenotypic profile correlated with the found AMEs encoding genes in 59.6% Ec-ESBL and 26.1% Kp-ESBL. In Ec-ESBL, aac(6′)-Ib was usually associated in 2000 with blaSHV (26.6%), but with blaCTX-M-1 group (34.8%) in 2006, while aac(3)-IIa was coincident in 2000 with blaTEM (14.6%) and with blaCTX-M-1 group (16.3%) in 2006. Among Kp-ESBL, the aac(6′)-Ib and aac(3)-IIa genes were more frequent in strains with blaTEM (22.0% and 44.0%) in 2000 and with blaCTX-M-1 group (46.4% and 34.0%) in 2006. Resistance to aminoglycosides in Ec-ESBL and Kp-ESBL is frequent and related to production of AMEs; this limits the clinical use of aminoglycosides against these organisms. [ABSTRACT FROM AUTHOR]

Background: Ambulances may represent a potential source of infection to patients, patients' relatives, and paramedical staffs. In this study, we analyzed the extent of bacterial contamination in ambulance vehicles and measured the degree of antimicrobial resistance among isolated pathogens. Materials and methods: Twenty-five vehicles were included and 16 sampling points were swabbed in each vehicle. Then the swabs were immediately transferred to the laboratory to identify bacterial contaminants utilizing standard microbiological procedures and API® systems. Antibiotic susceptibility testing and screening for methicillin-resistant staphylococci and extended spectrum β-lactamases (ESBLs)-producing Gram-negative rods were carried out. Results: A total of 400 samples were collected, 589 bacteria were isolated and 286 (48.6%) of the isolates were potentially pathogenic. The highest contamination rate with pathogenic bacteria was detected in suction devices (75.8%) and stethoscopes (67.7%). Staphylococci were the most frequently detected microorganisms (n=184) followed by Klebsiella spp. (49), Escherichia coli (40), Citrobacter spp. (7), and Proteus spp. (6). Staphylococci were mostly sensitive to vancomycin, whereas Gram-negative bacteria were sensitive to imipenem. Overall, 46.1% of Staphylococcus aureus were methicillin resistant, whereas 20.4% of the coagulasenegative staphylococci were methicillin resistant. Moreover, 36.7% of Klebsiella spp. and 27.5% of E. coli were ESBL producers. Conclusion: Our study provides evidence that ambulances represent a source of prehospital multidrug-resistant infections. [ABSTRACT FROM AUTHOR]

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Aim: The present study was conducted to record the association of extended spectrum β-lactamases (ESBLs) producing enteric bacteria with diarrhea of poultry birds in Mizoram, India. Materials and Methods: Fecal samples were collected from poultry birds with the history of diarrhea from different parts of Mizoram. Samples were processed for isolation and identification of Escherichia coli, Salmonella, and Klebsiella pneumoniae. All the isolates were subjected to antibiotic sensitivity assays. Phenotypically, ESBLs production ability was determined by double discs synergy test (DDST) method. ESBLs producing isolates were subjected to polymerase chain reaction (PCR) for detection of ESBLs genes. Plasmids were cured by acridine orange. Transfer of resistance from donor to recipient strains was done by in vitro horizontal method. Results: A total of 134 enteric bacteria was isolated, of which 102 (76.12%), 21 (15.67%) and 11 (8.21%) were E. coli, Salmonella spp. and K. pneumoniae, respectively. By DDST 7 (5.22%) isolates (6 E. coli and 1 K. pneumoniae) were ESBLs producer. PCR analysis confirmed 5 (3.73%) (4 E. coli and 1 K. pneumoniae) isolates harboured blaCTX-M-1 gene and/or blaTEM gene. All the isolates were carrying plasmids ranging between 0.9 kb and ~30 kb. Of the 4 isolates positive for blaCTX-M-1 and/or blaTEM, 2 (1.84%) were confirmed for blaCTX-M-1 gene in their plasmid. No blaTEM gene was detected from plasmid. The resistance plasmid could not be transferred to the recipient by in vitro horizontal gene transfer method. Conclusion: ESBLs producing enteric bacteria are circulating in poultry in North Eastern Region of India. As poultry is one of the most common food animals in this region, these organisms may enter in human population through them.

In this study, the presence of extended spectrum β-lactamase (ESBL)-producing Escherichia coli in aquatic environments (the Orontes River and an urban wastewater) was investigated. Fifty-four E. coli strains resistant to cefotaxime were isolated from the river waters and nearby waste water treatment plant and screened for ESBL gene variants, different classes of integrons and sulfonamide resistance genes. The ESBL-producing E. coli strains were further characterized by PhP-typing system, phylogenetic grouping and antimicrobial susceptibility testing. Of the 54 ESBL-producing strains, 14 (25.9%) belonged to four common PhP types and the remaining were of single types. CTX-M type ESBL genes were identified in 68% of the isolates. The most predominant specific CTX-M subtype identified was blaCTX-M-15 (n = 36), followed by blaCTX-M-1 (n = 1). None of the isolates were SHV and OXA positive. Most of the ESBL positive isolates (n = 37; 68.5%) were harboring sul gene. This study indicates a widespread distribution of CTX-M-15 producing E. coli strains in the surface waters in part of Turkey, suggesting an aquatic reservoir for ESBL genes. [ABSTRACT FROM AUTHOR]

Introduction: Urinary tract infections represent one of the most frequent reasons for hospitalization. As a result of their prevalence from community-based origins as well as those which develop in hospital setting, this constellation of infections represents a tremendous burden to the global healthcare system. Areas covered: Over the last several decades the management of these infections has become more complicated due to the underlying comorbid conditions of the patients as well as escalating antimicrobial resistance to many of the most frequently used oral and parenteral agents. One such example is the emergence of extend spectrum β-lactamase-producing (ESBL) bacteria that render many of the most frequently utilized oral and parenteral penicillin and cephalosporin based regimens of little clinical utility. As such new treatment strategies are required to effectively manage the growing population of patients with multi-drug resistant bacteria. Expert commentary: Herein, we review some of the current literature which reveals the challenges associated with the contemporary management of UTIs, while presenting strategies such as the implementation of clinical pathways that have the potential to enhance the quality and efficiency of care while reducing the overall cost of care. [ABSTRACT FROM AUTHOR]

Hospital-acquired and ventilator-associated pneumonia (HAP/VAP) due to extended-spectrum β-lactamase–producing Enterobacteriaceae (ESBL-PE) represent a growing problem. Indeed, ESBL-PE is endemic in many countries, and 5 to 25% of intensive care unit (ICU) patients are ESBL-PE carrier on ICU admission. ESBL-PE HAP/VAP is associated with a higher mortality than HAP/VAP due to susceptible Enterobacteriaceae because the resistance profile decreases the adequacy rate of empiric therapy. ESBL-PE should be considered in the empirical treatment in case of the high burden of ESBL-PE in the unit, in the case of previous ESBL-PE colonization, when the HAP/VAP occurs late, and in patients with shock. A negative active systematic surveillance culture on rectal swab reduced the risk of ESBL-PE VAP to less than 1%. Rapid diagnostic tests are now able to confirm the presence of ESBL-PE in VAP within 24 hours; new molecular methods will provide results within few hours.Adequate treatment usually required carbapenems. The alternative β-lactams such as β-lactams/β-lactamases inhibitor combinations could be proposed as a step-down therapy according to the antibiotic susceptibility result. Optimization of pharmacokinetics requires high dosage and continuous or prolonged infusions for β-lactams. When the patient is stabilized, a therapy of duration 7 to 8 days is recommended. [ABSTRACT FROM AUTHOR]

Microbial populations which are resistant to antibiotics are an emerging environmental concern with potentially serious implications for public health. Thus, there is a growing concern in exploring the occurrence of antibiotic resistance in the environment with no limitations to the factors that contribute to their emergence. The aquatic environment is considered to be a hot-spot for the acquisition and spread of antibiotic resistance due to pollution with emerging contaminants derived from anthropogenic activities. In this study, we report on the isolation and characterization of 141 Pseudomonas spp. from aquatic sediments receiving partially (un)treated hospital and communal effluents from three distinct geographical locations: Democratic Republic of the Congo (DRC), India (IN), and Switzerland (CH). P. putida (42%) and P. aeruginosa (39%) were the dominant Pseudomonas species. The highest frequency of antibiotic resistance against eight anti-pseudomonas agents was found among IN isolates (35–60%), followed by DRC (18–50%) and CH (12–54%). CTX-M was the most frequent β-lactamase found in CH (47% of isolates), while VIM-1 was dominant in isolates from DRC (61%) and IN (29%). NDM-1 was found in 29% of the total IN isolates and surprisingly also in 6% of CH isolates. Chromosomally-encoded efflux mechanisms were overexpressed in P. aeruginosa isolates from all three geographic locations. In vitro conjugative transfers of antibiotic resistance plasmids occurred more frequently under tropical temperatures (30 and 37 °C) than under temperate conditions (10 °C). The presence of Extended Spectrum β-lactamases (ESBLs) and Metallo β-lactamases (MBLs) in the isolates from environmental samples has important implications for humans who depend on public water supply and sanitation facilities. To our knowledge, this is the first study to demonstrate a comparison between treated/untreated effluents from urban and hospital settings as a source of microbial resistance by evaluating the aquatic ecosystems sediments from tropical and temperate climate conditions. Taken together, our findings demonstrate a widespread occurrence of antibiotic resistance in aquatic ecosystems sediments receiving untreated/treated wastewater and how these contemporary sources of contamination, contribute to the spread of microbial resistance in the aquatic environment. This research presents also useful tools to evaluate sediment quality in the receiving river/reservoir systems which can be applied to similar environments. [ABSTRACT FROM AUTHOR]

The contribution of the fresh produce production environment to human exposurewith bacteria bearing extended spectrum β-lactamases and AmpC β-lactamases (ESBL/AmpC) has not been reported. High prevalence of ESBLs/AmpC bearing E. coli as well as a high gene transfer efficiency of lettuce and irrigation water E. coli isolates was previously reported. This stochastic modeling was aimed at quantitatively assessing human exposure to ESBL/AmpC bearing E. coli through lettuce attributable to irrigation water and subsequent horizontal gene transfer. Modular process risk approach was used for the quantitative exposure assessment and models were constructed in Ms. Excel spreadsheet with farm to consumption chain accounted for by primary production, processing, retail and consumer storage. Probability distributionswere utilised to take into account the variability of the exposure estimates. Exposure resulting from ESBL/AmpC positive E. coli and gene transfer was taken into account. Monte Carlo simulation was carried out using @Risk software followed by sensitivity and scenario analysis to assess most effective single or combinations of mitigation strategies for the ESBL/AmpC positive E. coli events from farm to fork. Three percent of South African lettuce consumers are exposed to lettuce contaminated with about 106.4? 106.7 (95% CI: 105.1-107) cfu of ESBL/AmpC positive E. coli per serving. The contribution of originally positive isolates and conjugative genetic transfer was 106 ? 106.7 (95% CI: 105-107) and 105.2 ? 105.6 (95% CI: 103.9-105.8) cfu per serving respectively. Proportion of ESBL/AmpC positive E. coli (Spearman's correlation coefficient (ρ) = 0.85), conjugative gene transfer (ρ = 0.05-0.14), washing in chlorine water (ρ = 0.18), further rinsing (ρ = 0.15), and prevalence of E. coli in irrigation water (ρ = 0.16) had highest influence on consumer exposure. The most effective singlemethods in reducing consumer exposurewere reduction in irrigationwater microbial quality variation (87.4% reduction), storage period (49.9-87.4% reduction) and growth rate reduction by 75% (90% reduction). Reduction in growth rate together with storage time (92.1-99.4%) and reduction in storage time combined with E. coli concentration in irrigation water (95-96% reduction) were most effective combinations of mitigation measures. The high variation in exposure reflected the high irrigation water quality variation. The exposure levelsmay impose higher consumer risk than acceptable for irrigation water risk. E. coli contamination and growth related measures, as well as measures to reduce contamination with antimicrobial resistant E. coli from lettuce production environment are recommended. This exposure model could form a basis for the development of similar models assessing the impact of contaminated irrigation water and gene transfer in other microbial hazards, antimicrobial resistance types and fresh produce types. [ABSTRACT FROM AUTHOR]

Routine surveillance of resistance to broad-spectrum cephalosporins in Enterobacteriaceae and phenotypic identification of underlying mechanisms using a simple strategy was commenced in 2006 at our laboratory, serving West Norway. This report focuses on the results until 2013. The classical plasmid-mediated extended spectrum beta-lactamase ( ESBLA) among clinically relevant Escherichia coli isolates showed an increase from 0.6% to 4.3% during the surveillance period, while prevalence for other mechanisms remained stable, below 0.7%. ESBLA in Klebsiella pneumoniae had similar prevalence in 2006 (0.6%) and 2013 (4.4%), but in between it peaked to 3.9% in 2008 and to 9.3% in 2011. Within the other species, the numbers of clinically relevant isolates and isolates-producing ESBLA were much lower. An increasing resistance due to hyperproduction of AmpC enzymes was seen in Enterobacter and Citrobacter, with prevalence increasing from 18% and 12.2% in 2006 to 27.5% and 26.1% in 2013, respectively. Hyperproduction of KOXY enzyme in Klebsiella oxytoca remained below 9.5% and did not show an increasing trend. The overall increase in the proportions of isolates-producing ESBLA in E. coli/ K. pneumoniae and hyperproduction of AmpC in Enterobacter/ Citrobacter necessitates measures to hinder the spread of resistant bacteria and vigilant antibiotic stewardship. [ABSTRACT FROM AUTHOR]

Introduction. The choice of empiric therapy of acute pyelonephritis (APN) in children should be based on the knowledge of Escherichia coli (E. coli) as the most common uropathogen and its antibiotic sensitivities considering that nowadays ESBL-producing [ESBL (+)] E. coli is on the rise worldwide. Objective. To examine in vivo susceptibility of ESBL (+) E. coli to ceftriaxone (CTX), and to evaluate the options for empiric therapy for APN in children. Methods. Retrospective study of CTX empiric therapy of APN in children treated at the University Children΄s Hospital in Belgrade from January 2005 to December 2009. ESBL phenotypic confirmatory test with ceftazidime, CTX and cefotaxime was performed for all urine isolates by disc diffusion method on Mueller-Hinton agar plates. In vivo sensitivity of CTX documented by clinical response to empiric CTX therapy was compared between two groups of children: group I with ESBL (+) E. coli and group II with ESBL (-) E. coli APN. Results. Group I with ESBL (+) APN consisted of 94 patients and group II of 120 patients with ESBL (-) APN, respectively. All patients received CTX as empiric therapy at a mean dose of 66.9 mg during 7.2±2.6 days of therapy. Clinical effect of CTX was similar in patients with ESBL (+) compared to those with ESBL (-) APN. Conclusions. In vitro resistance of ESBL E. coli to CTX determined by standard methods is not sufficiently predictive for its in vivo sensitivity. Therefore CTX may be used as empiric therapy for acute pyelonephritis in children.

Increased multidrug resistance of extended-spectrum beta-lactamases (ESBLs) compromises the efficacy of treatment of urinary tract infections. The objective of this study is to determine the prevalence of ESBL-producing uropathogens from patients with chronic pyelonephritis (CP) and to evaluate the risk factors of these types of infections. Screening for the presence of plasmid-mediated ESBL was performed by polymerase chain reaction. Out of 105 patients, 22 (20.9%) revealed strains with resistance genes: 11 (36.7%), 11 (36.7%) and 8 (26.7%) were identified to carry bla(TEM), bla(SHV) and bla(CTX-M) beta-lactamase genes, respectively. We have demonstrated that prevalence of the resistance among patients with CP combined with type 2 DM was 31.3%, while among patients with CP without type 2 DM was 27.4%; however the difference between these groups was not significant. The main factors related with appearance of plasmid-mediated resistance genes were age range above 55 years, Chronic Kidney Disease stage ІІІ and ІV, in-patient treatment history, history of using antibiotics last year. Isolation and detection of ESBL-producing strains are essential fоr the sеlection оf the mоst effеctive antibiоtic for the empiric trеatment.

Infections due to extended spectrum β-lactamases (ESBL) producing Escherichia coli and Klebsiella pneumoniae have become an important clinical problem. Local knowledge of antimicrobial susceptibilities of these organisms is important for implementation of effective hospital anti-infective policies. The present study was undertaken to determine the prevalence of ESBLs along with their antimicrobial sensitivity pattern in Escherichia coli and klebsiella pneumoniae isolates at a tertiary care hospital in Bangalore. A total of 243 clinical isolates comprising E. coli (n=157) and K. pneumoniae (n=86) were recovered from various clinical samples over a period of six months from June to November 2008. Antibiogram profile of these isolates was determined by Kirby-Bauer’s disc diffusion method. All the isolates were screened for ESBL production as recommended by the Clinical Laboratory Standard Institute (CLSI). The present findings revealed a high occurrence of multidrug resistance ESBL producing E. coli (61.1%) and K. pneumoniae (40.6%). Imipenem was highly active against ESBL producing isolates. Results indicate that routine ESBL detection should be made imperative and empirical use of third generation cephaolsporins must be discouraged.

Extended spectrum β-lactamases production is one of the most common mechanism of resistance to extendedspectrum β-lactam antibiotics is increasing worldwide. Twenty five strains of Klebsiella pneumoniae isolated from clinicalspecimens were tested. Based on the phenotypic confirmatory test all these strains were defined as ESBL producers namedESBL(+). The plasmid DNA from each strains was used to investigate the presence of blaSHV genes responsible for extendedspectrum β-lactamases production. Moreover, susceptibility of these strains to antibiotic other than β-lactams in was tested.

INTRODUCTION: Salmonella sp infections have been reported over recent years in hospitals in Argentina and other countries due to multiresistant strains. The aim of this study was to characterize the extended-spectrum β-lactamases in third-generation cephalosporin-resistant strains of Salmonella enterica serovar Oranienburg. METHODS: We studied 60 strains isolated from children with gastroenteritis and/or extraintestinal complications. The antibiotic susceptibility patterns of the isolates were analyzed and the β-lactamases were characterized using phenotyping and genotyping methods. RESULTS: All the strains were resistant to ampicillin, cefotaxime, cefepime and aztreonam and partially susceptible to ceftazidime, thus corresponding well with the resistance phenotype conferred by CTX-M-type β-lactamases. An isoelectric point enzyme (pI = 7.9) was detected in all of the strains, and this was confirmed by PCR as a member of the CTX-M-2 group. CONCLUSIONS: This is the first report of Salmonella enterica serovar Oranienburg producing β-lactamases of the CTX-M-2 group in a pediatric hospital in Tucumán, Argentina.INTRODUÇÃO: Em recentes anos foram informadas infecções por Salmonella sp em hospitais da Argentina e outros países devido as cepas multiresistentes. O objetivo deste estudo era caracterizar as β-lactamasas de espectro extendido em cepas de Salmonella enterica serovar Oranienburg resistentes às cefalosporinas de terceira geração. MÉTODOS: Nós estudamos 60 cepas obtidas de pacientes com gastroenterites e com complicações extraintestinais. Os padrões de susceptibilidade antibiotica foram estudados em os isolamentos, as β-lactamasas foram caracterizadas por métodos fenotípicos e genotípicos. RESULTADOS: Todas as cepas eram resistentes a ampicillin, cefotaxime, cefepime e aztreonam e parcialmente suscetível a ceftazidime que corresponde bem com o fenótipo de resistência conferido por as β-lactamasas tipo CTX-M. Na totalidade das cepas, se detectou uma enzima de ponto isoelétrico (pI) 7,9, confirmada por PCR como pertencente ao grupo CTX-M2. CONCLUSÕES: Este é o primeiro reporte de Salmonella enterica serovar Oranienburg produtora de β-lactamasa grupo CTX-M2 em um hospital pediátrico de Tucuman, Argentina.

Aim Many extended-spectrum β-lactamases (ESBL) producingisolates of E. coli and K. pneumoniae are susceptible in vitro toamoxycillin-clavulanate (AMC), ceftazidime-clavulanate (CAZ/cl), and piperacillin-tazobactam (TZP), but MICs increase substantiallywhen higher inoculum is applied. The aim of this studywas to determine the effect of inoculum size on the susceptibilityof E. coli and K. pneumoniae isolates with well characterized ESBLs,to amoxycillin (AMX), AMC - amoxycilin + clavulanate,ceftazidime (CAZ), CAZ/cl - ceftazidime + clavulanate, piperacillin(PIP), TZP - tazobactam + piperacilin, imipenem (IMI) andmeropenem (MEM).Methods Minimum inhibitory concentrations (MIC) were determinedby broth microdilution method using inocula that differed100 fold in density.Results Inoculum effect for CAZ/cl was detected in 52% of SHV-2producing K. pneumoniae strains followed by AMC (43%) andTZP (38%). SHV-5 producing K. pneumoniae strains showed themost pronounced inoculum effect with CAZ/cl and AMC and tolesser extent with TZP. Inoculum effect was observed for AMC,CAZ/cl and TZP in 71% of SHV-12 producers. E. coli producingSHV-5 β-lactamase showed the most pronounced inoculumeffect with AMC, followed by CAZ/cl and TZP. Strains producingCTX-M β-lactamases had a marked inoculum effect with CAZ/cl,AMC and TZP. Carbapenems did not show inoculum effect withany type of ESBLs.Conclusion According to the results of this study, carbapenemsremain the antibiotics of choice for the treatment of infectionscaused by ESBL-producing Enterobacteriaceae.