Clonal Clusters, Molecular Resistance Mechanisms and Virulence Factors of Gram-Negative Bacteria Isolated from Chronic Wounds in Ghana

Wound infections are common medical problems in sub-Saharan Africa but data on the molecular epidemiology are rare. Within this study we assessed the clonal lineages, resistance genes and virulence factors of Gram-negative bacteria isolated from Ghanaian patients with chronic wounds. From a previous study, 49 Pseudomonas aeruginosa, 21 Klebsiellapneumoniae complex members and 12 Escherichia coli were subjected to whole genome sequencing. Sequence analysis indicated high clonal diversity with only nine P. aeruginosa clusters comprising two strains each and one E. coli cluster comprising three strains with high phylogenetic relationship suggesting nosocomial transmission. Acquired beta-lactamase genes were observed in some isolates next to a broad spectrum of additional genetic resistance determinants. Phenotypical expression of extended-spectrum beta-lactamase activity in the Enterobacterales was associated with blaCTX-M-15 genes, which are frequent in Ghana. Frequently recorded virulence genes comprised genes related to invasion and iron-uptake in E. coli, genes related to adherence, iron-uptake, secretion systems and antiphagocytosis in P. aeruginosa and genes related to adherence, biofilm formation, immune evasion, iron-uptake and secretion systems in K. pneumonia complex. In summary, the study provides a piece in the puzzle of the molecular epidemiology of Gram-negative bacteria in chronic wounds in rural Ghana.

Download Full-text

Folding Control in the Path of Type 5 Secretion

Toxins ◽

10.3390/toxins13050341 ◽

2021 ◽

Vol 13 (5) ◽

pp. 341

Author(s):

Nathalie Dautin

Keyword(s):

Protein Folding ◽

Virulence Factors ◽

Secretion System ◽

Gram Negative Bacteria ◽

Secretion Systems ◽

Gram Negative ◽

Final Destination ◽

Cell Compartments ◽

Recent Addition ◽

Functionally Diverse

The type 5 secretion system (T5SS) is one of the more widespread secretion systems in Gram-negative bacteria. Proteins secreted by the T5SS are functionally diverse (toxins, adhesins, enzymes) and include numerous virulence factors. Mechanistically, the T5SS has long been considered the simplest of secretion systems, due to the paucity of proteins required for its functioning. Still, despite more than two decades of study, the exact process by which T5SS substrates attain their final destination and correct conformation is not totally deciphered. Moreover, the recent addition of new sub-families to the T5SS raises additional questions about this secretion mechanism. Central to the understanding of type 5 secretion is the question of protein folding, which needs to be carefully controlled in each of the bacterial cell compartments these proteins cross. Here, the biogenesis of proteins secreted by the Type 5 secretion system is discussed, with a focus on the various factors preventing or promoting protein folding during biogenesis.

Download Full-text

AmpN-AmpG Operon Is Essential for Expression of L1 and L2 β-Lactamases in Stenotrophomonas maltophilia

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01283-09 ◽

2010 ◽

Vol 54 (6) ◽

pp. 2583-2589 ◽

Cited By ~ 22

Author(s):

Yi-Wei Huang ◽

Cheng-Wen Lin ◽

Rouh-Mei Hu ◽

Yu-Tzu Lin ◽

Tung-Ching Chung ◽

...

Keyword(s):

Stenotrophomonas Maltophilia ◽

Gene Dosage ◽

Gram Negative Bacteria ◽

Beta Lactamase ◽

Gene Dosage Effect ◽

Gram Negative ◽

E Coli ◽

Murein Sacculus ◽

Lactamase Gene ◽

L1 And L2

ABSTRACT AmpG is an inner membrane permease which transports products of murein sacculus degradation from the periplasm into the cytosol in Gram-negative bacteria. This process is linked to induction of the chromosomal ampC beta-lactamase gene in some members of the Enterobacteriaceae and in Pseudomonas aeruginosa. In this study, the ampG homologue of Stenotrophomonas maltophilia KJ was analyzed. The ampG homologue and its upstream ampN gene form an operon and are cotranscribed under the control of the promoter P ampN. Expression from P ampN was found to be independent of β-lactam exposure and ampN and ampG products. A ΔampN allele exerted a polar effect on the expression of ampG and resulted in a phenotype of null β-lactamase inducibility. Complementation assays elucidated that an intact ampN-ampG operon is essential for β-lactamase induction. Consistent with ampG of Escherichia coli, the ampN-ampG operon of S. maltophilia did not exhibit a gene dosage effect on β-lactamase expression. The AmpG permease of E. coli could complement the β-lactamase inducibility of ampN or ampG mutants of S. maltophilia, indicating that both species have the same precursor of activator ligand(s) for β-lactamase induction.

Download Full-text

Phenotypic Characterisation of Klebseilla pneumoniae Carbapenemase and Metallo Beta-lactamase in Carbapenem Resistant Gram-negative Bacteria

Indian Journal of Animal Research ◽

10.18805/ijar.b-4298 ◽

2021 ◽

Author(s):

Thresia . ◽

Surya Sankar ◽

Siju Joseph ◽

V.R. Ambily ◽

Anu Bosewell ◽

...

Keyword(s):

Confirmatory Test ◽

Diffusion Method ◽

Gram Negative Bacteria ◽

Beta Lactamase ◽

Disc Diffusion ◽

Beta Lactam ◽

Disc Diffusion Method ◽

Gram Negative ◽

E Coli ◽

Carbapenem Resistant

Background: Antibiotic resistance is an emerging concern in the therapy of clinical infections worldwide. Previous studies conducted in our laboratory have confirmed an increase in the prevalence of extended spectrum beta-lactamase (ESBL) among the Gram-negative bacterial pathogens associated with dogs, which could act as a potential source for the transfer of these resistant pathogens or their genetic determinants to human. Since carbapenems are the last resort drugs against these resistant pathogens, the study was aimed to isolate and characterise carbapenem resistance among Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae) and Pseudomonas aeruginosa (P. aeruginosa) associated with common clinical infections in dogs.Methods: A total of 100 samples were collected from lesional skin, urine and anterior vagina of dogs presented to the Veterinary Hospitals of Kerala Veterinary and Animal Sciences University at Mannuthy and Thrissur. The samples were cultured onto Brain Heart Infusion Agar (BHIA), Eosin Methylene Blue (EMB) and Mac Conkey (MAC) for isolation of bacteria. Identification of the isolates was performed based on cultural, morphological and biochemical characteristics. The isolates were subjected to antimicrobial susceptibility test (ABST) against the 12 commonly used beta-lactam and non–beta-lactam group of antibiotics by disc diffusion method and further subjected to screening for ESBL double disc diffusion method. Carbapenem-resistant isolates were subjected to phenotypic confirmatory test for carbapenemase production employing Imipenem-EDTA and Ertapenem-boronic acid minimum inhibitory concentration (MIC) strip method.Result: Forty four Gram-negative bacterial isolates obtained were viz., E. coli (30), K. pneumonia (11) and P. aeruginosa (3) from the 100 samples. Apart from these, other isolates obtained were Staphylococcus spp. (53) and Bacillus spp. (2). All the Gram-negative isolates were subjected to ABST employing 12 common antibiotics belonging to beta-lactam and non-beta-lactam groups. Multidrug resistance (MDR) could be observed in 28 E. coli, 11 K. pneumoniae and three P. aeruginosa isolates. All the 42 MDR isolates showed positive results for ESBL production. A total of 14 isolates out of the 44 Gram-negative bacilli were found to be resistant to carbapenem either to imipenem, meropenem or ertapenem. Among the 14 Gram-negative isolates, nine turned out to be positive for metallo-beta-lactamase (MBL) and none for K. penumoniae carbapenemase (KPC) on phenotypic confirmatory test for detecting major carbapenemase enzymes. The present study documented that Gram- negative bacteria like E. coli, K. pneumoniae and P. aeruginosa isolated from dogs are showing an increase rate of resistance against carbapenems which are the last resort drugs against ESBL producers. Hence, there is an urgent need to curb the irrational and excessive use of antibiotics in veterinary sector.

Download Full-text

Antibiotic resistance and detection of plasmid mediated colistin resistance mcr-1 gene among Escherichia coli and Klebsiella pneumoniae isolated from clinical samples

Gut Pathogens ◽

10.1186/s13099-021-00441-5 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Deepa Karki ◽

Binod Dhungel ◽

Srijana Bhandari ◽

Anil Kunwar ◽

Prabhu Raj Joshi ◽

...

Keyword(s):

Escherichia Coli ◽

Drug Resistance ◽

Klebsiella Pneumoniae ◽

Clinical Samples ◽

Gram Negative Bacteria ◽

Beta Lactamase ◽

Drug Resistant ◽

Colistin Resistance ◽

Gram Negative ◽

E Coli

Abstract Background The prevalence of antimicrobial resistance (AMR) among Gram-negative bacteria is alarmingly high. Reintroduction of colistin as last resort treatment in the infections caused by drug-resistant Gram-negative bacteria has led to the emergence and spread of colistin resistance. This study was designed to determine the prevalence of drug-resistance among beta-lactamase-producing strains of Escherichia coli and Klebsiella pneumoniae, isolated from the clinical specimens received at a tertiary care centre of Kathmandu, Nepal during the period of March to August, 2019. Methods A total of 3216 different clinical samples were processed in the Microbiology laboratory of Kathmandu Model Hospital. Gram-negative isolates (E. coli and K. pneumoniae) were processed for antimicrobial susceptibility test (AST) by using modified Kirby-Bauer disc diffusion method. Drug-resistant isolates were further screened for extended-spectrum beta-lactamase (ESBL), metallo-beta-lactamase (MBL), carbapenemase and K. pneumoniae carbapenemase (KPC) production tests. All the suspected enzyme producers were processed for phenotypic confirmatory tests. Colistin resistance was determined by minimum inhibitory concentration (MIC) using agar dilution method. Colistin resistant strains were further screened for plasmid-mediated mcr-1 gene using conventional polymerase chain reaction (PCR). Results Among the total samples processed, 16.4% (529/3216) samples had bacterial growth. A total of 583 bacterial isolates were recovered from 529 clinical samples. Among the total isolates, 78.0% (455/583) isolates were Gram-negative bacteria. The most predominant isolate among Gram-negatives was E. coli (66.4%; 302/455) and K. pneumoniae isolates were 9% (41/455). In AST, colistin, polymyxin B and tigecycline were the most effective antibiotics. The overall prevalence of multidrug-resistance (MDR) among both of the isolates was 58.0% (199/343). In the ESBL testing, 41.1% (n = 141) isolates were confirmed as ESBL-producers. The prevalence of ESBL-producing E. coli was 43% (130/302) whereas that of K. pneumoniae was 26.8% (11/41). Similarly, 12.5% (43/343) of the total isolates, 10.9% (33/302) of E. coli and 24.3% of (10/41) K. pneumoniae were resistant to carbapenem. Among 43 carbapenem resistant isolates, 30.2% (13/43) and 60.5% (26/43) were KPC and MBL-producers respectively. KPC-producers isolates of E. coli and K. pneumoniae were 33.3% (11/33) and 20% (2/10) respectively. Similarly, 63.6% (21/33) of the E. coli and 50% (5/10) of the K. pneumoniae were MBL-producers. In MIC assay, 2.2% (4/179) of E. coli and 10% (2/20) of K. pneumoniae isolates were confirmed as colistin resistant (MIC ≥ 4 µg/ml). Overall, the prevalence of colistin resistance was 3.1% (6/199) and acquisition of mcr-1 was 16.6% (3/18) among the E. coli isolates. Conclusion High prevalence of drug-resistance in our study is indicative of a deteriorating situation of AMR. Moreover, significant prevalence of resistant enzymes in our study reinforces their roles in the emergence of drug resistance. Resistance to last resort drug (colistin) and the isolation of mcr-1 indicate further urgency in infection management. Therefore, extensive surveillance, formulation and implementation of effective policies, augmentation of diagnostic facilities and incorporation of antibiotic stewardship programs can be some remedies to cope with this global crisis.

Download Full-text

Antimicrobial resistance profile of extended-spectrum beta-lactamases, adenosine-monophosphate-cyclic, and carbapenemase-producing Gram-negative bacteria isolated from domestic animals

Veterinary World ◽

10.14202/vetworld.2021.3099-3104 ◽

2021 ◽

pp. 3099-3104

Author(s):

Jôiciglecia Pereira dos Santos ◽

Valesca Ferreira Machado de Souza ◽

Marcos Wilker da Conceição Santos ◽

Juliany Nunes dos Santos ◽

Natilene Silva dos Santos ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Adenosine Monophosphate ◽

Domestic Animals ◽

Gram Negative Bacteria ◽

Beta Lactamase ◽

Gram Negative ◽

Beta Lactamases ◽

E Coli ◽

Antimicrobial Resistance Profile ◽

Chromogenic Agar

Background and Aim: The production of beta-lactamase enzymes, such as extended-spectrum beta-lactamase (ESBL), adenosine-monophosphate-cyclic (AmpC), and Klebsiella pneumoniae carbapenemase (KPC), is one of the most important mechanisms of bacterial resistance to antimicrobials. Gram-negative bacteria show significant resistance due to various intrinsic and acquired factors. These intrinsic factors include low permeability of the outer membrane, various efflux systems, and the production of beta-lactamases, while acquired factors include chromosomal mutation and acquisition of resistance genes by horizontal transfer. Mobile elements such as plasmids, integrative conjugative elements, mobilizable islands, or transposable elements are involved in horizontal transfer. At present, the Gram-negative pathogens of most concern are Acinetobacter baumannii, Pseudomonas aeruginosa, and those belonging to the Enterobacteriaceae family (e.g., Escherichia coli, K. pneumoniae, and Proteus mirabilis). This study aimed to evaluate the profile of antimicrobial resistance and the production of the enzymes ESBL, AmpC, and KPC, in 21 gram-negative bacteria isolated from domestic animals treated at the University Veterinary Hospital (HVU) of the Federal University of Western Bahia (UFOB). Materials and Methods: The biological samples (21) were inoculated to brain heart infusion broth, blood agar, and MacConkey agar and incubated for 24-72 h at 37°C. Gram staining and identification through biochemical tests and matrix-associated laser desorption/ionization time-of-flight mass spectrometry were conducted. To evaluate the antimicrobial resistance profile, the disk diffusion method was used, and 25 antibiotics were employed. For the detection of ESBL, the disk approximation method was applied using chromogenic agar. The presence of KPC was observed using chromogenic agar and the Hodge test. For AmpC evaluation, the disk approximation method was used. Results: The most isolated agent was E. coli (66.66%, 14/21), followed by K. pneumoniae and P. mirabilis (both 14.29%, 3/21), and then Pasteurella spp. (4.76%, 1/21). The bacterial isolates showed high levels of resistance against clindamycin, penicillin, imipenem, polymyxin, cefoxitin, gentamycin, cefotaxime, ceftazidime, cephalothin, ceftriaxone, ciprofloxacin, trimethoprim/sulfamethoxazole, chloramphenicol, and tetracycline. The best effectiveness rates were observed for cefepime, streptomycin, amoxicillin-clavulanate, aztreonam, nalidixic acid, tobramycin, levofloxacin, amikacin, and meropenem. All biological isolates showed multiple resistance to at least three of the antibiotics tested (3/25), and some showed resistance to 24 of the antibiotics tested (24/25). Among the 21 pathogens analyzed, 8 were ESBL producers (38.09%); of these, 6 were identified as E. coli (28.57%), and 2 were identified as K. pneumoniae (9.52%). Two strains of K. pneumoniae produced both ESBL and KPC. None of the isolates were producers of AmpC. Conclusion: The results found in the present work raise concern about the level of antimicrobial resistance among pathogens isolated from domestic animals in Brazil. The results highlight the need for the development and implementation of anti-resistance strategies to avoid the dissemination of multiresistant pathogens, including the prudent use of antimicrobials and the implementation of bacterial culture, antimicrobial sensitivity, and phenotypic tests for the detection of beta-lactamase enzymes in bacteria isolated from animals.

Download Full-text

175. Antibiotic Resistance in Select Gram-negative Bacteria Over the Past Decade Among Hospitalized Veterans Nationally

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab466.175 ◽

2021 ◽

Vol 8 (Supplement_1) ◽

pp. S107-S108

Author(s):

J Xin Liao ◽

Vrishali Lopes ◽

Haley J Appaneal ◽

Kerry LaPlante ◽

Aisling Caffrey

Keyword(s):

Antibiotic Resistance ◽

Multi Drug Resistance ◽

Gram Negative Bacteria ◽

Beta Lactamase ◽

Morganella Morganii ◽

Gram Negative ◽

Extended Spectrum Beta Lactamase ◽

E Coli ◽

Extended Spectrum ◽

Research Grant

Abstract Background Public health institutions including the World Health Organization and the United States Centers for Disease Control and Prevention (CDC) have recognized the threat of antibiotic resistant infections caused by Gram-negative bacteria. These bacteria are particularly concerning as they can demonstrate resistance to all available antibiotic classes through various mechanisms. We set out to assess antibiotic resistance trends in Gram-negative bacteria to optimize antimicrobial stewardship and infection control initiatives in our health system. Methods We identified positive cultures (1st per patient per month) of P. aeruginosa and select Enterobacterales (Citrobacter, Escherichia coli, Enterobacter, Klebsiella, Morganella morganii, Proteus mirabilis, Serratia marcescens) collected from patients hospitalized at Veterans Affairs (VA) Medical Centers nationally from 2011 to 2020. Time trends were assessed with joinpoint regression to estimate average annual percent changes (AAPC) with 95% confidence intervals (CIs) for the following resistance phenotypes utilizing CDC definitions: multi-drug resistance (MDR), extended-spectrum beta-lactamase (ESBL), and carbapenem (CR) and fluoroquinolone (FR) resistance. Results We included 496,384 isolates in our study: E. coli (32.6%), Klebsiella (20%), P. aeruginosa (18.9%), P. mirabilis (11.5%), Enterobacter (7.8%), Citrobacter (3.7%), S. marcescens (2.9%), and M. morganii (2.6%). Trends in resistance are shown in the figures. MDR, ESBL, CR, and FR decreased significantly (p< 0.05) over the study period for most of the organisms assessed, with the exception of MDR and ESBL E. coli and CR P. mirabilis which remained stable, and CR M. morganii which increased significantly by 7.1% per year (95% CI 0.2% to 14.5%). The largest decreases were in CR E. coli by 29.5% per year (95% CI -36.5% to -21.8%), CR Klebsiella by 23.7% per year (95% CI -27.6% to -19.5%), and MDR and CR S. marcescens by 12.2% (95% CI -14.4% to -9.9%) and 12.3% per year (95% CI -16.2% to -8.1%), respectively. Figure 1. Antibiotic resistance trends in Citrobacter spp., E. coli, Enterobacter spp., and Klebsiella spp. Antibiotic resistance trends (by percentage) in (a) Citrobacter spp, (b) E. coli, (c) Enterobacter spp, and (d) Klebsiella spp from 2011-2020. Abbreviations: MDR = multi-drug resistance (defined as non-susceptible to at least 1 drug in at least 3 of the following categories: extended-spectrum cephalosporins, fluoroquinolones, aminoglycosides, carbapenems, piperacillin/tazobactam); ESBL = extended spectrum beta-lactamase (defined as non-susceptible to at least 1 of the following drugs: cefepime, ceftriaxone, cefotaxime, ceftolozane/tazobactam, ceftazidime/avibactam); CR = carbapenem resistance (defined as non-susceptible to at least 1 carbapenem); FR = fluoroquinolone resistance (defined as non-susceptible to at least 1 fluoroquinolone); AAPC = annual average percentage change; CI = confidence interval. Figure 2. Antibiotic resistance trends in Pseudomonas aeruginosa, Proteus mirabilis, Serratia marcescens, and Morganella morganii. Antibiotic resistance trends (by percentage) in (e) Pseudomonas aeruginosa, (f) Proteus mirabilis, (g) Serratia marcescens, and (h) Morganella morganii from 2011-2020. Abbreviations: MDR = multi-drug resistance (defined as non-susceptible to at least 1 drug in at least 3 of the following categories: extended-spectrum cephalosporins, fluoroquinolones, aminoglycosides, carbapenems, piperacillin/tazobactam); ESBL = extended spectrum beta-lactamase (defined as non-susceptible to at least 1 of the following drugs: cefepime, ceftriaxone, cefotaxime, ceftolozane/tazobactam, ceftazidime/avibactam); CR = carbapenem resistance (defined as non-susceptible to at least 1 carbapenem); FR = fluoroquinolone resistance (defined as non-susceptible to at least 1 fluoroquinolone); AAPC = annual average percentage change; CI = confidence interval. Conclusion Overall, MDR, ESBL, CR, and FR in Enterobacterales and P. aeruginosa decreased from 2011 to 2020 in the VA. These results may be related to the robust infection control and antimicrobial stewardship programs instituted among VA Medical Centers nationally. Disclosures Kerry LaPlante, PharmD, Merck (Research Grant or Support)Pfizer Pharmaceuticals (Research Grant or Support)Shionogi, Inc (Research Grant or Support) Aisling Caffrey, PhD, Merck (Research Grant or Support)Pfizer (Research Grant or Support)Shionogi, Inc (Research Grant or Support)

Download Full-text

Beta-Lactamase Resistance Genes in Enterobacteriaceae from Nigeria

10.20944/preprints202008.0635.v1 ◽

2020 ◽

Author(s):

Babafela Awosile ◽

Michael Agbaje ◽

Oluwawemimo Adebowale ◽

Olugbenga Kehinde ◽

Ezekiel Omoshaba

Keyword(s):

Molecular Epidemiology ◽

Resistance Genes ◽

Gram Negative Bacteria ◽

Beta Lactamase ◽

Eligibility Criteria ◽

Gram Negative ◽

Beta Lactamases ◽

Extended Spectrum ◽

Carbapenemase Gene ◽

Extended Spectrum Beta Lactamases

This review was carried out to identify different beta-lactamase resistance genes reported in published literature from Nigeria and to determine the proportion estimates of the important beta-lactamase resistance genes in Nigeria. Sixty-three (63) articles were included in this review based on the eligibility criteria. All the beta-lactamases reported were detected from the Gram-negative bacteria, most especially from Enterobacteriaceae (n=53). Thirty-six different beta-lactamase genes have been reported from Nigeria. These genes belong to the narrow-spectrum, AmpC, extended-spectrum, and carbapenemase beta-lactamase resistance genes. Eight (8) genes (blaDHA, blaCTXM-1, blaCTXM-14, blaGES-1, blaVEB-1, blaOXA-1, blaOXA-2, and blaTEM-1) were shared between animals and humans, 5 genes (blaSHV-1, blaSHV-2, blaSHV-11, blaSHV-12, and blaNDM-1) were common to both humans and environment while none of the genes was unique to both animals and environment. Four genes including blaCMY, blaTEM-1, blaAmpC, and internationally pandemic blaCTXM-15 gene were unique to animals, humans, and the environment. No carbapenemase gene was reported from animals yet. The pooled proportion estimate of ESBL genes in Nigeria was 31% (95% CI: 26-36%, P<0.0001), while the estimate of blaCTXM-15 gene in Nigeria was 46% (95% CI: 36-57%, P<0.0001). The proportion estimate of AmpC genes was 32% (95% CI: 11-52%, P<0.001), while the estimate for carbapenemases was 8% (95% CI: 5-12%, P<0.001). This study has provided information on the beta-lactamases distribution in Nigeria. This is necessary for a better understanding of molecular epidemiology of clinically important beta-lactamases especially the extended-spectrum beta-lactamases and carbapenemases in Nigeria.

Download Full-text

Prevalence and antimicrobial susceptibility of extended-spectrum beta-lactamase producing urinary isolates of Escherichia coli in outpatients

Srpski arhiv za celokupno lekarstvo ◽

10.2298/sarh1312775m ◽

2013 ◽

Vol 141 (11-12) ◽

pp. 775-779 ◽

Cited By ~ 1

Author(s):

Tatjana Markovic ◽

Ljiljana Jeinic ◽

Aleksandra Smitran ◽

Miroslav Petkovic

Keyword(s):

Escherichia Coli ◽

Antimicrobial Susceptibility ◽

Gram Negative Bacteria ◽

Beta Lactamase ◽

Age Group ◽

Gram Negative ◽

Extended Spectrum Beta Lactamase ◽

E Coli ◽

Esbl Producers ◽

Urinary Isolates

Introduction. In Gram-negative bacteria, the production of beta-lactamases is the most important mechanism of resistance to beta-lactam antibiotics. In the Banja Luka region, there were no extensive researches on the prevalence and antimicrobial resistance of the extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli) isolates. Objective. The aim of the present study was to determine the presence of ESBL producing E. coli isolates as the cause of the urinary tract infections in outpatients, the distribution of these ESBL isolates according to age and gender of patients and their susceptibility to antimicrobials. Methods. Urine specimens obtained from outpatients were cultured on chromogenic CPS-ID3 media. All plates showing significant (>105 cfu/ml) growth of E. coli in pure culture were further processed. Antimicrobial susceptibility testing was performed on VITEK TWO Compact using AST-GN27 cards for testing Gram negative bacteria and detection of ESBL producers. Results. Out of 2,195 isolates, 177 (8.1%) were ESBL producers. Ninety-two isolates were obtained from female patients (5% of E. coli isolated from women) and 85 isolates from male patients (23% of E. coli isolated from men). High percentage of ESBL isolates was detected in the infant age group under one year (36.7%) and in the age group over 60 years (28.8%). All ESBL isolates were susceptible to imipenem and resistant to ampicillin, piperacillin, cefazolin, cefotaxime, ceftazidime and cefepime. There was a significant resistance to amikacin (79.1%), gentamicin (76.8%), amoxicillin/clavulanate (54.8%) and trimethoprim/sulphamethoxazole (45.8%). Resistance to nutrofurantoin was 13.6%. Conclusion. This study has demonstrated the presence of ESBL producing E. coli urinary isolates in outpatients, and their extensive susceptibility to imipenem and nitrofurantoin.

Download Full-text

Opening Pandora’s box: high level resistance to antibiotics of last resort in Gram negative bacteria from Nigeria

10.1101/344093 ◽

2018 ◽

Author(s):

David O Ogbolu ◽

Laura J V Piddock ◽

Mark A Webber

Keyword(s):

Resistance Mechanisms ◽

Sub Saharan Africa ◽

Gram Negative Bacteria ◽

Gram Negative ◽

E Coli ◽

First Line Therapy ◽

Sub Saharan ◽

High Level ◽

Third Generation Cephalosporins ◽

Level Resistance

ABSTRACTAntimicrobial resistance (AMR) is a global problem but information about the prevalence and mechanisms of resistance in sub-Saharan Africa are lacking. We determined the percentage of drug resistant isolates and resistance mechanisms in 307 Gram negative isolates randomly collected from south western Nigeria. Susceptibility testing revealed 78.1%, 92.2% and 52.6% of all isolates were resistant to fluoroquinolones, third generation cephalosporins and carbapenems respectively. There were more resistant isolates from the stools of uninfected patients than from specimens of patients with symptoms of infections. Only a small proportion of E. coli (10%) and Klebsiella (7%) isolates produced a carbapenemase. Whole genome sequencing of selected isolates identified the presence of globally disseminated clones. This depicts a crisis for the use of first line therapy in Nigerian patients, it is likely that Nigeria is playing a significant role in the spread of AMR due to her high population and mobility across the globe.

Download Full-text

Multidrug resistance and extended-spectrum beta-lactamase producing Gram-negative bacteria from three Referral Hospitals of Amhara region, Ethiopia

Annals of Clinical Microbiology and Antimicrobials ◽

10.1186/s12941-021-00422-1 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Feleke Moges ◽

Mucheye Gizachew ◽

Mulat Dagnew ◽

Azanaw Amare ◽

Bekele Sharew ◽

...

Keyword(s):

Drug Resistance ◽

Clinical Samples ◽

Gram Negative Bacteria ◽

Beta Lactamase ◽

Amhara Region ◽

Gram Negative ◽

Extended Spectrum Beta Lactamase ◽

E Coli ◽

Extended Spectrum ◽

Referral Hospitals

Abstract Background Multidrug resistance (MDR), extended-spectrum beta-lactamase (ESBL) and carbapenemase-producing Gram-negative bacteria (GNB) has become a public health threat worldwide. This threat is worse in developing countries where there is high infectious disease burden and spread of antimicrobial resistance co-exist. The aim of the present study was, therefore, to assess MDR, ESBL and carbapenemase producing GNB from patients attending three selected referral hospitals in Amhara region. Methods A cross-sectional study was conducted from December 2017- April 2018 at the University of Gondar Comprehensive Specialized Hospital, Dessie Referral Hospital and Debre Markos Referral Hospital of Amhara national regional state. A total of 833 study subjects were recruited using a convenient sampling technique. Clinical samples such as blood, urine, stool, wound, abscess, ear discharge, nasal discharge, cervical discharge and body fluid specimens were aseptically collected. Culturing for identification of bacteria and determination of drug susceptibility testing were done following standard microbiological techniques. Selected MDR isolates were phenotypically assessed for ESBL and carbapenemase production. Results Of the 833 clinical samples cultured for bacterial growth, 141 (16.9%) were positive for GNB. The most common GNB identified were E. coli 46 (32.6%), Klebsiella spp. 38 (26.5%) and Proteus spp. 13 (9.2%). The overall MDR prevalence was 121 (85.8%). Among the total isolates, 137 (97.2%) were resistant to ampicillin followed by cotrimoxazole 115 (81.6%), amoxicillin-clavulanic acid 109 (77.3%), cefixime 99 (70.2%), cefepime 93 (66.0%) and tetracycline 91 (64.5%). The extended-spectrum beta-lactamase producing GNB were 69/124 (55.6%). Of which Klebsiella spp. 19 (15.3%) and E. coli 17 (13.7%) were common ESBL producers. Carbapenemase-producing isolates were 8/51(15.7%). Of which Enterobacter, Klebsiella and E. coli were common carbapenemase producers. Conclusion and recommendation Multi-drug resistance and ESBL producing isolates in the present study were high. E. coli and Klebsiella spp. were the most common ESBL producing GNB. Klebsiella spp., Enterobacter spp., E. coli and Citrobacter spp. were typical carbapenemase-producing isolates. Continuous monitoring, antibiotic stewardship and molecular detection of the gene responsible for drug resistance are important means to reduce the spread of drug-resistant pathogens.

Download Full-text