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Klebsiella pneumoniae is a common pathogen capable of causing a wide range of infections. Antibiotic resistance complicates treatment of these infections significantly. We are comparing resistance levels and genotypes among two collections of K. pneumoniae clinical isolates from Alexandria Main University Hospital (AMUH). We used disc diffusion and Minimum Inhibitory Concentration (MIC) by microbroth dilution to assess resistance levels and performed whole genome sequencing (WGS) to describe multilocus sequence types (MLST) and resistance gene presence. Among a collection of 56 K. pneumoniae clinical isolates (19 from 2019 to 37 from 2021), multidrug resistance (MDR) was 33% and 10%, extended drug resistance (XDR) was 24% and 46% and pan-drug resistance (PDR) was 43% and 43%, respectively. We identified 15 MLST STs including two novel types (ST-6118 and ST-6119 ). ST-101 and ST-383 were common between the two collections; ST-101 was the most common genotype in 2019 (28.6%) and ST-147 was most common in 2021 (25%). Ampicillin/sulbactam, amikacin, cefepime, ceftriaxone and ertapenem MICs were significantly higher in 2021. Prevalence of aph(3') - Ia, aph(3')-VI, mphA was significantly higher in 2021. The increasing resistance levels and the persistence of some MDR/XDR genotypes is concerning. Understanding mechanisms of resistance will inform infection control and antimicrobial stewardship plans to prevent evolution and spread of XDR and PDR strains.
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Antibacterianos , COVID-19 , Genótipo , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Egito/epidemiologia , Humanos , COVID-19/epidemiologia , Antibacterianos/farmacologia , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/tratamento farmacológico , Farmacorresistência Bacteriana Múltipla/genética , Tipagem de Sequências Multilocus , SARS-CoV-2/genética , SARS-CoV-2/efeitos dos fármacos , Sequenciamento Completo do Genoma/métodos , Pandemias , Farmacorresistência Bacteriana/genéticaRESUMO
INTRODUCTION: Extended-spectrum ß-lactamase (ESBL)-producing pathogenic E. coli is a global public health issue, especially in sub-Saharan African countries such as Cameroon. It contributes to increase significantly hospital length of stay, morbidity, mortality and economic costs because of treatment failures. This study aims at determining the resistance background and virulence profiles of ESBL-E. coli isolates among childhood diarrhoea during the cholera outbreak occuring in Yaoundé, Cameroon. MATERIALS AND METHODS: During a four-month periods, from March 1st to June 30th, 2023, a total of 84 stool samples were collected from 90 under five children presenting clinical signs of gastroenteritis and attending four hospitals in Yaoundé, Cameroon. Bacterial identification was done using API20E and antimicrobial susceptibility test was performed using the Kirby-Bauer disc diffusion method. After extraction, genomic DNA was subjected to conventional and multiplex polymerase chain reaction methods (PCRs) for detection of resistance and virulence genes. Statistical analysis was performed using Epi info™ (7.2.5.0). Statistical significance was considered at a p-value < 0.05. RESULTS: Out of 150 patients contacted, 90 patients were enrolled, 84 samples were collected, 52.38%(44/84) and 3.57%(03/84) were confirmed as extended-spectrum ß-lactamase and carbapenemase-producing E. coli respectively. The risk factors were analyzed, and children who drank natural fruit juice (OR: 0.4, p-value: 0.03) were found to be significantly associated with ESBL-producing E. coli. The ESBL-producing E. coli isolates showed a high level of resistance to amoxicillin-clavulanic acid, cefotaxime, ceftazidime, cefepime, colistin, and tetracycline. The blaCTX-M was more prevalent ß-lactamase resistance gene. The tetracycline resistance genes tet(A) and tet(B) were also detected. The most important virulence genes detected were FimH (81.81%) and papA (79.54%). CONCLUSION: These findings suggest implementing routine surveillance and screening for antimicrobial resistance among children under five. Antimicrobial stewardship strategies (ASP) need to be implemented to curb the emergence and dissemination of ESBL-producing E. coli. In addition, a national surveillance program for antimicrobial resistance needs to be implemented at local and regional levels in order to reduce morbidity in Cameroon.
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Antibacterianos , Diarreia , Infecções por Escherichia coli , Escherichia coli , Fezes , Testes de Sensibilidade Microbiana , beta-Lactamases , Humanos , beta-Lactamases/genética , beta-Lactamases/metabolismo , Camarões/epidemiologia , Diarreia/microbiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/epidemiologia , Pré-Escolar , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Escherichia coli/patogenicidade , Escherichia coli/enzimologia , Feminino , Lactente , Masculino , Antibacterianos/farmacologia , Fezes/microbiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Fatores de Virulência/genética , Farmacorresistência Bacteriana Múltipla/genéticaRESUMO
BACKGROUND: Escherichia coli is the most common etiological agent of urinary tract infections (UTIs). Meanwhile, plasmid-mediated quinolone resistance (PMQR) is reported in E. coli isolates producing extended-spectrum ß-lactamases (ESBLs). Furthermore, the reservoirs and mechanisms of acquisition of uropathogenic Escherichia coli (UPEC) strains are poorly understood. On the other hand, UTIs are common in pregnant women and the treatment challenge is alarming. METHODS AND RESULTS: In the present study, 54 pregnant women with acute cystitis were included. A total of 108 E. coli isolates, 54 isolates from UTI and 54 isolates from faeces of pregnant women (same host) were collected. In the antimicrobial susceptibility test, the highest rate of antibiotic resistance was to nalidixic acid (77%, 83/108) and the lowest rate was to imipenem (9%, 10/108). Among the isolates, 44% (48/108) were ESBLs producers. A high frequency of PMQR genes was observed in the isolates. The frequency of PMQR genes qnrS, qnrB, aac(6')-Ib-cr, and qnrA was 58% (63/108), 21% (23/108), 9% (10/108), and 4% (4/108), respectively. Meanwhile, PMQR genes were not detected in 24% (20/85) of isolates resistant to nalidixic acid and/or fluoroquinolone, indicating that other mechanisms, i.e. chromosomal mutations, are involved in resistance to quinolones, which were not detected in the present study. In ESBL-producing isolates, the frequency of PMQR genes was higher than that of non-ESBL-producing isolates (81% vs. 53%). Meanwhile, UTI and faeces isolates mainly belonged to phylogenetic group B2 (36/54, 67% and 25/54, 46%, respectively) compared to other phylogenetic groups. In addition, virulence factors and multidrug-resistant (MDR) were mainly associated with phylogenetic group B2. However, predominant clones in faeces were not found in UTIs. Rep-PCR revealed the presence of 85 clones in patients. Among the clones, 40 clones were detected only in faeces (faeces-only), 35 clones only in UTI (UTI-only) and 10 clones in both faeces and UTI (faeces-UTI). We found that out of 10 faeces-UTI clones, 5 clones were present in the host's faeces flora. CONCLUSION: This study revealed a high rate of resistance to the quinolone nalidixic acid and a widespread distribution of PMQR genes in MDR E. coli strains producing ESBLs. The strains represented virulence factors and phylogenetic group B2 are closely associated with abundance in UTI and faeces. However, the predominant clones in faeces were not found in UTIs and it is possible that rep-PCR is not sufficiently discriminating clones.
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Antibacterianos , Cistite , Infecções por Escherichia coli , Escherichia coli , Fezes , Testes de Sensibilidade Microbiana , Plasmídeos , Quinolonas , beta-Lactamases , Humanos , Feminino , beta-Lactamases/genética , Plasmídeos/genética , Fezes/microbiologia , Quinolonas/farmacologia , Gravidez , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/tratamento farmacológico , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Adulto , Antibacterianos/farmacologia , Cistite/microbiologia , Farmacorresistência Bacteriana/genética , Prevalência , Infecções Urinárias/microbiologia , Ácido Nalidíxico/farmacologiaRESUMO
BACKGROUND: Hospital-acquired infections caused by multidrug-resistant Pseudomonas aeruginosa incline hospital stay and costs of treatment that resulted in an increased mortality rate. The frequency of P. aeruginosa high-risk clones producing carbapenemases was investigated in our clinical samples. METHODS: In this cross-sectional study, 155 non-repetitive P. aeruginosa isolates were included from different medical centers of Iran. Antibiotic susceptibility testing was determined, and the presence of ß-lactamases were sought by phenotypic and genotypic methods. The clonal relationship of all isolates was investigated, and multi-locus sequence typing (MLST) was used for finding the sequence types of carbapenemase-producers. RESULTS: The agent with highest percent susceptibility rate was recorded for colistin (94.9%). MOX and FOX were found both as low as 1.95% (3/155). The most frequent narrow spectrum ß-lactamase was SHV with 7.7% (12/155) followed by PER, OXA-1, and TEM with the frequency of 7.1% (11/155), 3.2% (5/155), and 1.3% (2/155), respectively. Carbapenemases were detected in 28 isolates (18%). The most frequent carbapenemase was IMP with 9% (14/155) followed by NDM, 8.4% (13/155). OXA-48 and VIM were also detected both per one isolate (0.65%). MLST of carbapenem resistant P. aeruginosa isolates revealed that ST244, ST664, ST235, and ST357 were spread in subjected clinical settings. REP-PCR uncovered high genomic diversity in our clinical setting. CONCLUSION: Clonal proliferation of ST235 strain plays a key role in the propagation of MDR pattern in P. aeruginosa. Our data showed that high-risk clones has distributed in Iran, and programs are required to limit spreading of these clones.
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Infecções por Pseudomonas , Pseudomonas aeruginosa , Humanos , Pseudomonas aeruginosa/genética , Tipagem de Sequências Multilocus , Irã (Geográfico) , Estudos Transversais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , beta-Lactamases/genética , Proteínas de Bactérias/genética , Infecções por Pseudomonas/tratamento farmacológico , Testes de Sensibilidade Microbiana , GenômicaRESUMO
BACKGROUND: Proteus mirabilis is an opportunistic pathogen that has been held responsible for numerous nosocomial and community-acquired infections which are difficult to be controlled because of its diverse antimicrobial resistance mechanisms. METHODS: Antimicrobial susceptibility patterns of P. mirabilis isolates collected from different clinical sources in Mansoura University Hospitals, Egypt was determined. Moreover, the underlying resistance mechanisms and genetic relatedness between isolates were investigated. RESULTS: Antimicrobial susceptibility testing indicated elevated levels of resistance to different classes of antimicrobials among the tested P. mirabilis clinical isolates (n = 66). ERIC-PCR showed great diversity among the tested isolates. Six isolates (9.1%) were XDR while all the remaining isolates were MDR. ESBLs and AmpCs were detected in 57.6% and 21.2% of the isolates, respectively, where blaTEM, blaSHV, blaCTX-M, blaCIT-M and blaAmpC were detected. Carbapenemases and MBLs were detected in 10.6 and 9.1% of the isolates, respectively, where blaOXA-48 and blaNDM-1 genes were detected. Quinolone resistant isolates (75.8%) harbored acc(6')-Ib-cr, qnrD, qnrA, and qnrS genes. Resistance to aminoglycosides, trimethoprim-sulfamethoxazole and chloramphenicol exceeded 80%. Fosfomycin was the most active drug against the tested isolates as only 22.7% were resistant. Class I or II integrons were detected in 86.4% of the isolates. Among class I integron positive isolates, four different gene cassette arrays (dfrA17- aadA5, aadB-aadA2, aadA2-lnuF, and dfrA14-arr-3-blaOXA-10-aadA15) and two gene cassettes (dfrA7 and aadA1) were detected. While class II integron positive isolates carried four different gene cassette arrays (dfrA1-sat1-aadA1, estXVr-sat2-aadA1, lnuF- dfrA1-aadA1, and dfrA1-sat2). CONCLUSION: P. Mirabilis ability to acquire resistance determinants via integrons may be held responsible for the elevated rates of antimicrobial resistance and emergence of XDR or even PDR strains limiting the available therapeutic options for management of infections caused by those strains.
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Antibacterianos , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Infecções por Proteus , Proteus mirabilis , Egito/epidemiologia , Humanos , Proteus mirabilis/genética , Proteus mirabilis/efeitos dos fármacos , Proteus mirabilis/isolamento & purificação , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Proteus/microbiologia , Infecções por Proteus/epidemiologia , Antibacterianos/farmacologia , Prevalência , beta-Lactamases/genética , Integrons/genética , Proteínas de Bactérias/genética , Infecção Hospitalar/microbiologia , Infecção Hospitalar/epidemiologia , MasculinoRESUMO
OBJECTIVES: Pseudomonas aeruginosa (P. aeruginosa) is one of the most serious pathogens implicated in antimicrobial resistance, and it has been identified as an ESKAPE along with other extremely significant multidrug resistance pathogens. The present study was carried out to explore prevalence, antibiotic susceptibility phenotypes, virulence-associated genes, integron (int1), colistin (mcr-1), and ß-lactamase resistance' genes (ESBls), as well as biofilm profiling of P. aeruginosa isolated from broiler chicks and dead in-shell chicks. DESIGN: A total of 300 samples from broiler chicks (n = 200) and dead in-shell chicks (n = 100) collected from different farms and hatcheries located at Mansoura, Dakahlia Governorate, Egypt were included in this study. Bacteriological examination was performed by cultivation of the samples on the surface of both Cetrimide and MacConkey's agar. Presumptive colonies were then subjected to biochemical tests and Polymerase Chain Reaction (PCR) targeting 16S rRNA. The recovered isolates were tested for the presence of three selected virulence-associated genes (lasB, toxA, and exoS). Furthermore, the retrieved isolates were subjected to phenotypic antimicrobial susceptibility testing by Kirby-Bauer disc diffusion method as well as phenotypic detection of ESBLs by both Double Disc Synergy Test (DDST) and the Phenotypic Confirmatory Disc Diffusion Test (PCDDT). P. aeruginosa isolates were then tested for the presence of antibiotic resistance genes (ARGs): int1, mcr-1, and ESBL genes (OXA-10, OXA-2, VEB-1, SHV, TEM, and CTX-M). Additionally, biofilm production was examined by the Tube Adherent method (TA) and Microtiter Plate assay (MTP). RESULTS: Fifty -five isolates were confirmed to be P. aeruginosa, including 35 isolates from broiler chicks and 20 isolates from dead in-shell chicks. The three tested virulence genes (lasB, toxA, and exoS) were detected in all isolates. Antibiogram results showed complete resistance against penicillin, amoxicillin, ceftriaxone, ceftazidime, streptomycin, erythromycin, spectinomycin, and doxycycline, while a higher sensitivity was observed against meropenem, imipenem, colistin sulfate, ciprofloxacin, and gentamicin. ESBL production was confirmed in 12 (21.8%) and 15 (27.3%) isolates by DDST and PCDDT, respectively. Antibiotic resistance genes (ARGs): int1, mcr-1, and ESBL genes (OXA-10, SHV, TEM, and CTX-M), were detected in 87.3%, 18.2%, 16.4%, 69.1%, 72.7%, and 54.5% of the examined isolates respectively, whereas no isolate harbored the OXA-2 or VEB-1 genes. Based on the results of both methods used for detection of biofilm formation, Kappa statistics [kappa 0.324] revealed a poor agreement between both methods. CONCLUSIONS: the emergence of mcr-1 and its coexistence with other resistance genes such as ß-lactamase genes, particularly blaOXA-10, for the first time in P. aeruginosa from young broiler chicks and dead in-shell chicks in Egypt pose a risk not only to the poultry industry but also to public health.
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Infecções por Pseudomonas , Pseudomonas aeruginosa , Animais , Pseudomonas aeruginosa/genética , Galinhas , RNA Ribossômico 16S , Antibacterianos/farmacologia , beta-Lactamases , Infecções por Pseudomonas/veterinária , Testes de Sensibilidade MicrobianaRESUMO
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 blaTEM gene was present in all the isolates, and these carried the blaCTX 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.
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Doenças dos Bovinos , Infecções por Escherichia coli , Mastite Bovina , Feminino , Animais , Bovinos , Escherichia coli/genética , Mastite Bovina/epidemiologia , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Lactação , Prevalência , Antibacterianos/farmacologia , China/epidemiologia , Fluoroquinolonas/uso terapêuticoRESUMO
Objective: Identification of MBL, AmpC and ESBLs in colistin intrinsic and acquired resistant uropathogenic gram negative bacteria. Method: Urine samples were collected from Hayatabad Medical Complex, Peshawar during 17 January to 30 June 2019. Collected urine samples were aseptically transported microbiology lab of Health Research Institution (HRI), National Institute of Health (NIH), Khyber Medical College, Peshawar and streaked on different media. Positive growth was identified by API-10s. Antibiotic sensitivity profile was done by Modified Kirby Bauer disc diffusion method. Detection of metallo ßlactamases (MBL) production by Imipenem EDTA synergy test, Double Disc Synergy Test (DDST) for detection of ESBLs and D-test for the detection of inducible AmpC beta lactamases test was used. Colistin resistance was identified via broth micro dilution according to CLSI manual. Colistin resistant bacteria was divided in two categories; acquired and intrinsic resistant bacteria according to CLSI manual. Results: Out of 2000 urine samples, 281(14%) gram-negative bacteria were isolated. Among positive samples, acquired colistin resistant bacteria were 241 and intrinsic resistant bacteria were 40 isolates. MBL was produce by twenty one (11.7%) E.coli and seventeen (40.5%) Pseudomonas aeruginosa. E. coli, Pseudomonas aeruginosa, Klebsiella Pneumoniae, Serratia Oderifora and Proteus Marblis were ESBLs producing bacteria. AmpC production was prevalent in fourteen (7.8%) E. coli and twelve (28.6%) Pseudomonas aeruginosa. Fifty-five samples showed resistance to colistin out of 241 samples. In colistin resistant bacteria, two E.coli were MBL, ESBLs, while one E.coli was ESBLs, AmpC co-producing bacteria. The most prevalent extended drug resistant bacteria were Pseudomonas aeruginosa (28.6%) and Escherichia coli (6.1%), While 155(86.6%) Escherichia coli, 25 (59.5%) Pseudomonas aeruginosa and 22 (95.7%) Serratia Oderifora was multi drug resistant bacteria. Conclusion: Current study concluded that ESBL, MBL AmpC enzymes and their co-expression was observed with colistin resistance in E.coli and Pseudomonas aeruginosa.
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In the present study, a total of 102 samples were collected from chickens of different flocks, died due to suspected colibacillosis. Bacteriological and PCR methods were applied to detect avian pathogenic Escherichia coli (APEC). Phenotypic antimicrobial resistance (AMR) was determined by disk diffusion method. Extended spectrum beta lactamases (ESBL) detection was carried out via PCR by targeting blaTEM, blaSHV, blaOXA, and blaCTX-M groups 1, 2, and 9. Genes of eight virulence factors and class I integrons were also detected by PCR using gene specific primers. Culture, microscopic, biochemical tests and PCR recognised 69/102 (67.64%) samples as E. coli. Phenotypic AST revealed higher resistance against fluoroquinolone antibiotics, i.e., enrofloxacin (72.46%), levofloxacin (69.56%) & ciprofloxacin (66.66%), followed by amoxyclav (63.77%) and tetracycline (59.42%). Six isolates were found as pan-drug-resistant E. coli. A total of 48 (69.56%) and 7 (10.14%) isolates were positive for the presence of blaTEM and blaCTX-M-G9 genes, respectively, whereas 2 (2.90%) isolates each were found positive for blaSHV, blaOXA, and blaCTX-M-G1 genes. Among APEC associated virulence genes, iss (79.71%) was the most predominant, followed by tsh (50.72%), ast (30.43%), cvaf (26.08%), pap (23.18%), vat (8.69%) and stx-1 (1.44%). Thirty-two isolates harboured class I integrons, either with or without ESBL genes. Conclusively, the isolates under study showed pan and multiple-drug resistance, specifically against fluoroquinolone drugs. ESBL production was mediated principally through bla TEM and blaCTX-M-G9. Multiple virulence factors, toxins, and carriage & spread factor render these as zoonotically potential pathogens for humans. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01132-2.
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BACKGROUND: Investigations into antibiotics for extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E) bloodstream infections (BSIs) have focused on blaCTX-M genes. Outcomes of patients with non-CTX-M-producing ESBL-E BSIs and optimal treatment are unknown. METHODS: A multicenter observational study investigating 500 consecutive patients with ceftriaxone-resistant Enterobacterales BSIs during 2018-2022 was conducted. Broth microdilution and whole genome sequencing confirmed antibiotic susceptibilities and ESBL gene presence, respectively. Inverse probability weighting (IPW) using propensity scores was employed to ensure patients infected with non-CTX-M and CTX-M ESBL-E BSIs were similar prior to evaluation of outcomes. RESULTS: 396 patients (79.2%) were confirmed to have an ESBL-E BSI. ESBL gene family prevalence was as follows: blaCTX-M (n=370), blaSHV (n=16), blaOXY (n=12), and blaVEB (n=5). ESBL gene identification was not limited to Escherichia coli and Klebsiella species. In the IPW cohort, there was no difference in 30-day mortality or ESBL-E infection recurrence between the non-CTX-M and CTX-M groups (OR=.99, 95% CI 0.87-1.11; p=0.83) and (OR=1.10, 95% CI 0.85--1.42; p=0.47), respectively. In an exploratory analysis limited to the non-CTX-M group, 86% of the 21 patients receiving meropenem were alive on day 30; none of the 5 patients receiving piperacillin-tazobactam were alive on day 30. CONCLUSIONS: Our findings suggest that non-CTX-M and CTX-M ESBL-producing Enterobacterales BSIs are equally concerning and associated with similar clinical outcomes. Meropenem may be associated with improved survival in patients with non-CTX-M ESBL-E BSIs, underscoring the potential benefit of comprehensive molecular diagnostics to enable early antibiotic optimization for patients with ESBL-E BSI, beyond just blaCTX-M genes.
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The ubiquitous emergence of bacterial resistance is a challenging problem in infectious diseases treatment. Recently, new research lines employed nano-drug delivery systems to enhance antibacterial activity of the existing antibiotics. Accordingly, the objective of this study is to optimize surfactant nanovesicles to improve the antimicrobial effect of meropenem, ertapenem and tigecycline against Carbapenemase Resistant Enterobacteriaceae (CRE) and extended spectrum beta-lactamases producing bacteria (ESBL). Klebsiella pneumoniae and Escherichia coli were used as the test organisms. In vivo and in vitro evaluations were conducted to prove the efficacy of niosome-encapsulated drugs formulations. The results revealed that surfactant vesicles were able to reduce the MIC values of the tested drugs by nine-fold change compared to their free forms. Scanning Electron Microscope (SEM) showed possible adhesion/fusion of the vesicles encapsulated drugs on the bacterial cells compared to its solution. In vivo investigations using animal skin model confirmed the superiority of nanovesicles drug encapsulation regarding both wound size and histopathological examination. Wound surface area was reduced from 24.6mm2 in absence of drug to reach 13.9, and 6.2mm2 in presence of ertapenem solution or niosomes, respectively. Nanovesicular formulations can be considered as effective drug delivery systems that can diminish bacterial resistance against ß-lactams antibiotics.
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Infecções Bacterianas , Enterobacteriaceae , Animais , Ertapenem/farmacologia , Tensoativos/farmacologia , Antibacterianos/farmacologia , beta-Lactamases , Bactérias , Escherichia coli , Klebsiella pneumoniae , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: Antimicrobial resistant infections continue to be a leading global public health crisis. Mobile genetic elements, such as plasmids, have been shown to play a major role in the dissemination of antimicrobial resistance (AMR) genes. Despite its ongoing threat to human health, surveillance of AMR in the United States is often limited to phenotypic resistance. Genomic analyses are important to better understand the underlying resistance mechanisms, assess risk, and implement appropriate prevention strategies. This study aimed to investigate the extent of plasmid mediated antimicrobial resistance that can be inferred from short read sequences of carbapenem resistant E. coli (CR-Ec) in Alameda County, California. E. coli isolates from healthcare locations in Alameda County were sequenced using an Illumina MiSeq and assembled with Unicycler. Genomes were categorized according to predefined multilocus sequence typing (MLST) and core genome multilocus sequence typing (cgMLST) schemes. Resistance genes were identified and corresponding contigs were predicted to be plasmid-borne or chromosome-borne using two bioinformatic tools (MOB-suite and mlplasmids). RESULTS: Among 82 of CR-Ec identified between 2017 and 2019, twenty-five sequence types (STs) were detected. ST131 was the most prominent (n = 17) followed closely by ST405 (n = 12). blaCTX-M were the most common ESBL genes and just over half (18/30) of these genes were predicted to be plasmid-borne by both MOB-suite and mlplasmids. Three genetically related groups of E. coli isolates were identified with cgMLST. One of the groups contained an isolate with a chromosome-borne blaCTX-M-15 gene and an isolate with a plasmid-borne blaCTX-M-15 gene. CONCLUSIONS: This study provides insights into the dominant clonal groups driving carbapenem resistant E. coli infections in Alameda County, CA, USA clinical sites and highlights the relevance of whole-genome sequencing in routine local genomic surveillance. The finding of multi-drug resistant plasmids harboring high-risk resistance genes is of concern as it indicates a risk of dissemination to previously susceptible clonal groups, potentially complicating clinical and public health intervention.
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Infecções por Escherichia coli , Escherichia coli , Humanos , Escherichia coli/genética , Carbapenêmicos/farmacologia , Tipagem de Sequências Multilocus , Antibacterianos/farmacologia , Plasmídeos/genética , Infecções por Escherichia coli/epidemiologia , beta-Lactamases/genética , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: The 2017 World Health Organization (WHO) report has listed extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E) as critical pathogens for public health and requiring urgently new antibiotics. The aim of this study was to characterize phenotypically and genotypically ESBL-E isolated among clinical samples in Dschang, Cameroon. METHODS: A cross-sectional study was conducted during a four-month periods from February to May 2022 in the two biggest hospitals of Dschang. Clinical samples were collected and cultured on Eosin Methylene Blue agar. Suspected growing colonies were biochemically identified using the Enterosystem Kit 18R. Antimicrobial susceptibility testing (AST) was done using the Kirby Bauer disc diffusion method and interpretated according to the CA-SFM recommendations. ESBL phenotypes were double screened using CHROMagar™ ESBL and double disk synergy test (DDST). The detection of resistance genes was performed using conventional and multiplex PCR methods. Results were analyzed with SPSS (version 21) and a p-value < 0.05 was considered statistically significant. RESULTS: A total of 152 Enterobacterales were isolated among 597 clinical samples including urine, blood, cervico-vaginal, urethral swabs and wound samples. The overall prevalence of ESBL-Enterobacterales was 29.61% (45/152). The most represented ESBL species were Escherichia coli (n = 23; 51.11%), Klebsiella pneumoniae (n = 8; 17.78%) and Citrobacter freundii (n = 6; 13.33%). CONCLUSION: This study reveals the high burden of ESBL-E among clinical samples in the regional hospital in Dschang with the most common species being E. coli and K. pneumoniae. It confirmed the high occurrence of blaCTX-M and blaTEM among ESBL-E. The study suggests that implementing antimicrobial stewardship program and real-time surveillance of antimicrobial resistance are needed in the Western region of Cameroon. Moreover, the implementation of infection prevention and control measures (IPC) is essential to curb the dissemination of these bacteria from community to hospital settings. Implementation of national action plan to fight against antimicrobial resistance at the local levels is urgently needed.
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Escherichia coli , beta-Lactamases , Feminino , Humanos , beta-Lactamases/genética , Camarões/epidemiologia , Estudos Transversais , Klebsiella pneumoniae , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , FenótipoRESUMO
INTRODUCTION: Nosocomial infections (NIs) are a major challenge worldwide. Identification of antibiotic resistance pattern extended spectrum beta-lactamases (ESBLs) and carbapenem-resistant Enterobacteriaceae (CRE) were the objectives of this study. METHODS: In this cross-sectional study, the antimicrobial susceptibility pattern of bacterial isolates collected from patients with NIs in ICU was determined. Overall, 42 Escherichia coli and Klebsiella pneumoniae isolates from different infection sites were used to determine phenotypic tests of ESBLs, Metallo-ß-lactamases (MBLs) and CRE. Detection of ESBLs, MBLs and CRE genes were performed by the polymerase chain reaction (PCR) method. RESULTS: From 71 patients with NIs, 103 different bacterial strains were isolated. The most frequently isolated bacteria were E. coli (n = 29; 28.16%), Acinetobacter baumannii (n = 15; 14.56%), and K. pneumoniae (n = 13; 12.26%). Also, the rate of multidrug-resistant (MDR) isolates was 58.25% (60/103). Based on phenotypic confirmation tests, 32 (76.19%) isolates of E. coli and K. pneumoniae produced ESBLs, and 6 (14.28%) isolates were identified as CRE producers. PCR showed the high prevalence of the blaCTX-M (n = 29; 90.62%) in ESBL genes. In addition, blaNDM was detected in 4 (66.66%), blaOXA-23 in 3 (50%), and blaOXA-48 gene in 1 (16.66%) isolates. The blaVIM, blaKPC, and blaIMP genes were not detected in any of the isolates. CONCLUSION: The Gram-negative bacteria E. coli, A. baumannii, and K. pneumoniae with high resistance levels were the most common bacteria causing NIs in the ICU. This study for the first time identified blaOXA-11, blaOXA-23, and blaNDM-1 genes in E. coli and K. pneumoniae in Ilam city of Iran.
Assuntos
Anti-Infecciosos , Enterobacteriáceas Resistentes a Carbapenêmicos , Infecção Hospitalar , Humanos , Escherichia coli/genética , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Irã (Geográfico)/epidemiologia , Estudos Transversais , Clero , Testes de Sensibilidade Microbiana , beta-Lactamases/genética , Hospitais , Klebsiella pneumoniae/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/genéticaRESUMO
Extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases (AmpCs)-producing Enterobacteriaceae have been increasingly reported and imposing significant threat to public. Livestock production industry might be the important source for clinically important ESBL-producing Enterobacteriaceae. This study aims to investigate the resistance profile, phenotypic ESBL production, beta-lactamase genes, virulence factors, and plasmid replicon types among 59 Enterobacteriaceae strains isolated from poultry faecal samples in Malaysia's commercial poultry farm. There were 38.7% and 32.3% of Escherichia coli resistant to cefotaxime and cefoxitin, respectively, while Klebsiellaspp. demonstrated resistance rate of 52.6% to both mentioned antimicrobials. Majority of the E. coli isolates carried blaTEM and blaCMY-2 group. blaSHV was the most prevalent gene detected in Klebsiellaspp., followed by blaDHA and blaTEM. Resistance to extended spectrum cephalosporin in our isolates was primarily mediated by plasmid mediated AmpC beta-lactamase such as CMY-2 group and DHA enzyme. The CTX-M genes were found in two ESBL-producing E. coli. IncF, IncI1, and IncN plasmids were most frequently detected in E. coli and Klebsiellaspp. The virulence factor, including EAST1 and pAA were identified at low frequency. This study highlights the poultry as a reservoir of resistance and virulence determinants and prevalence of plasmids in Enterobacteriaceae might drive their dissemination.
Assuntos
Infecções por Escherichia coli , Escherichia coli , Animais , Escherichia coli/genética , Aves Domésticas , Infecções por Escherichia coli/veterinária , Fazendas , Enterobacteriaceae/genética , Malásia , Proteínas de Bactérias/genética , beta-Lactamases/genética , Plasmídeos , AntibacterianosRESUMO
High bacterial community diversity and complexity greatly challenge the cost-efficient monitoring of clinically prevalent antibiotic-resistant bacteria, which are usually present as rare and important populations involved in the environmental dissemination of clinical resistance. Here, we introduce culture-enriched phenotypic metagenomics that integrates culture enrichment, phenotypic screening, and metagenomic analyses as an emerging standardized methodology for targeted resistome monitoring and apply it to decipher the extended-spectrum ß-lactam resistome in a municipal wastewater treatment plant (WWTP) and its receiving river. The results showed that clinically prevalent carbapenemase genes (e.g., the NDM and KPC families) and extended-spectrum ß-lactamase genes (e.g., the CTX-M, TEM, and OXA families) were prevalent in the WWTP and showed prominent potential in horizontal dissemination. Strikingly, carbapenem and polymyxin resistance genes co-occurred in the highly virulent nosocomial pathogens Enterobacter kobei and Citrobacter freundii. Overall, this study exemplifies phenotypic metagenomics for high-throughput surveillance of a targeted clinically important fraction of antibiotic resistomes and substantially expands current knowledge on extended-spectrum ß-lactam resistance in WWTPs.
Assuntos
Metagenômica , Resistência beta-Lactâmica , beta-Lactamas , Antibacterianos/farmacologia , Bactérias/genética , Carbapenêmicos , Testes de Sensibilidade Microbiana , Purificação da Água , Resistência beta-Lactâmica/genética , beta-Lactamases/genética , beta-Lactamas/farmacologiaRESUMO
BACKGROUND AND OBJECTIVES: Burn patients are highly susceptible to invasion by multidrug-resistant Gram-negative bacteria (MDR-GNB) through post-burn damage. The prevalence of MDR-GNB isolated from burns patients has increased dramatically in the last decade, representing a serious risk to patients admitted to burns units worldwide. The challenges of managing infected burns patients are exacerbated in poor resource settings. This study was designed to develop a pathway for the rapid diagnosis of multidrug-resistant (MDR) Gram-negative infections and identify the bacterial genes including blaOXA1, blaTEM, and blaSHV encoding ESBLs and blaOXA48, blaKPC, blaNDM, and blaVIM encoding carbapenemases from the patient of post burns infection. METHODS: Clinical isolates were collected (August 2017 to August 2018) from Intensive care unit (ICU) of Burn Centre. Antibiotic susceptibility testing and phenotypic detection of ESBLs and carbapenemases was performed by disk diffusion, double disk synergy test (DDST), combination disk test (CDT), and Imipenem + EDTA combined disk test (IMP + EDTA CDT). Polymerase chain reaction (PCR) detection was performed for ESBLs blaOXA1-blaSHV-blaTEM and carbapenemases genes blaOXA48-blaKPC-blaNDM-blaVIM RESULTS: In total, of 170 Gram-negative isolates, 104 (61.2%) were confirmed as multidrug-resistant (MDR); Pseudomonas aeruginosa was found to be the most prevalent 43/104 (41.4%), followed by Klebsiella pneumoniae 17/104 (16.4%), Acinetobacter baumannii12/104 (11.5%), and 6/104 Proteus mirabilis (5.8%). All isolates (100%) were resistant to cefotaxime and ceftazidime, while the meropenem resistance was 58.7%. ESBL and carbapenemase genotypes were found to be associated with higher MAR index (0.65-0.88) and MIC (> 32 µg/ml) values P. aeruginosa was the major ESBL and carbapenemase producer as determined by phenotypic testing and PCR. blaTEM positive isolates among ESBLs producers were predominant 81.8% (27/33), followed by 27.3% blaOXA1 and blaSHV, respectively. blaVIM positive isolates among carbapenemase producers were predominant 47.7% (21/44), followed by 27.3% blaKPC, 20.5% blaOXA48, and 11.4% blaNDM positive isolates. CONCLUSIONS: The predominant organism causing burn infections was ESBL and carbapenemase-producing Pseudomonas aeruginosa. There are only limited effective antibiotics against such strains. blaVIM and blaTEM individually and in co-existence with blaKPC, blaOXA48, blaSHV, and blaOXA1 confer antimicrobial resistance in burns patients. Rapid detection of ESBL and carbapenemase genes will inform treatment strategies improving the outcome for post-burn patients in ICU.
Assuntos
Proteínas de Bactérias , beta-Lactamases , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , Ácido Edético , Bactérias Gram-Negativas/genética , Humanos , Unidades de Terapia Intensiva , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa , beta-Lactamases/genéticaRESUMO
INTRODUCTION: Detection of Extended-Spectrum Beta-Lactamases (ESBLs) depends on screening for resistance to certain cephalosporins, confirmation with selective ESBL inhibitors, and ESBL genes detection. New tests are required for accurate ESBL detection. AIMS: To test the ability of cefixime (CFM) and cefixime-amoxicillin/clavulanate (CFM-AMC) as a screening and confirmatory test for ESBL identification. METHODS: 246 clinical isolates of Escherichia coli were tested by an ESBL screening test, a double-disk synergy test (DDST), a disk replacement test, the Vitek 2 ESBL test, and an ESBL genes test by PCR. CFM ESBL Screening was performed by disk diffusion, while CFM-AMC confirmation was performed by DDST and a disk replacement test. RESULTS: 246 E. coli clinical isolates from two referral hospitals were collected over 2 years. The mean age ± standard deviation of patients was 43.8 ± 27.7 years and 76.8% were females. Resistance rates to penicillins, first, second, and third generation cephalosporins, and monobactams were very high at 97%, 84%, 100% and 97%, respectively. ESBL screening was positive in 81.3% of isolates, DDST was positive in 74.8%, disk replacement was positive in 79%, Vitek 2 ESBL test was positive in 67.3%, and ESBL genes were detected in 85.8% of isolates (CTX-M 75%, TEM 42.5%, SHV 4.6%). Compared to genotyping, screening with CFM achieved 87.7% sensitivity and 64.7% specificity. CFM-AMC DDST achieved 75.8% sensitivity and 75.4% specificity, and CFM-AMC disk replacement had 73% sensitivity and 70% specificity. CONCLUSIONS: High prevalence of ESBLs was noted among E. coli isolates, dominated by CTX-M genotype. ESBL screening and confirmation using CFM and CFM-AMC is a new and accurate method for ESBLs detection.
Assuntos
Infecções por Escherichia coli , Escherichia coli , Adolescente , Adulto , Idoso , Cefixima/farmacologia , Cefalosporinas/farmacologia , Ácido Clavulânico , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Adulto Jovem , beta-Lactamases/análise , beta-Lactamases/genéticaRESUMO
Clinical characteristics of bacteremic urinary tract infection due to third-generation cephalosporin-resistant Escherichia coli in children remain unclear. We conducted a case control study comparing the clinical information of the third-generation cephalosporin-susceptible group (S-E. coli group) and the third-generation cephalosporin-resistant group (R-E. coli group). The R-E. coli group included extended-spectrum beta-lactamases (ESBLs) or AmpC-producing E. coli. We identified 52 cases of bacteremic UTI due to E. coli; 42 cases were in the S-E. coli group and 10 cases were in the R-E. coli group. Empiric antibiotics were more likely to be inappropriate for pediatric patients with bacteremic urinary tract infection due to third-generation cephalosporin-resistant E. coli than those infected by susceptible E. coli (60% vs. 0%, P < 0.001). However, duration of fever and rate of relapse were not significantly different. The outcomes of bacteremic UTI due to multidrug-resistant E. coli in children were satisfactory regardless of susceptibility to empiric antibiotics.
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Infecções por Escherichia coli , Infecções Urinárias , Antibacterianos/uso terapêutico , Estudos de Casos e Controles , Cefalosporinas/uso terapêutico , Criança , Escherichia coli , Infecções por Escherichia coli/tratamento farmacológico , Humanos , Infecções Urinárias/tratamento farmacológico , beta-LactamasesRESUMO
In the present study a total of 200 Klebsiella pneumoniae isolates were collected from patients with urinary tract infections (UTIs) in Tehran, Iran. Antibiotic resistance was determined by disk diffusion and broth dilution methods. Detection of extended-spectrum ß-lactamases (ESBLs) and AmpCs was performed using phenotypic tests. Polymerase chain reaction (PCR) was applied to detect the ESBL, AmpC, and integron genes. Analysis of AmpC and cassette arrays of integron genes was performed using DNA sequencing. Plasmids were analyzed by PCR-based replicon typing and conjugation. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were applied to explore the genomic relatedness among the isolates. The highest levels of resistance were observed against ampicillin (100%), followed by piperacillin (57.5%), ceftazidime (46%), trimethoprim/sulfamethoxazole (44%), ciprofloxacin (32.5%), and imipenem (19%). Approximately, 66.5% of isolates harbored at least one of the beta-lactamase genes (blaTEM, blaSHV, blaCTX-M, and blaOXA-1). In addition, 22.5% of isolates carried at least one of the AmpC genes including blaDHA and blaCIT. Integron class I was the most prevalent integron among resistant isolates. According to the results of replicon typing, IncFII, IncL/M, and IncA/C were the most frequent replicons, respectively. All selected isolates were able to transfer blaCTX-M, also two isolates transferred the blaDHA-1 gene to Escherichia coli K12 through conjugation. Finally, 21 isolates were categorized into 4 pulsotypes and 11 unique clusters in PFGE. MLST identified ST147 and ST11 sequence types but ST147 was the most prevalent in the current study.