Prevalence and Molecular Characterization of Extended Spectrum β-Lactamase and Carbapenemase-Producing Enterobacteriaceae Isolates from Bloodstream Infection Suspected Patients in Addis Ababa, Ethiopia

Molecular detection of extended-spectrum β-lactamase- and carbapenemase-producing Klebsiella pneumoniae isolates in southwest Iran

OBJECTIVE

The global emergence of carbapenem-resistant Klebsiella pneumoniae is considered a significant contemporary concern., as carbapenems are the last resort for treating infections caused by multidrug-resistant Gram-negative bacteria. This study aimed to investigate the carbapenem-resistance genes in extended-spectrum β-lactamase producing K. pneumoniae isolates.

METHODS

Seventy-five non-duplicate clinical K. pneumoniae strains were isolated from urine, blood, sputum, and wound samples. Antimicrobial susceptibility tests for 12 different antibiotics were performed using the disk diffusion method, followed by determining minimum inhibitory concentrations of imipenem and meropenem. Phenotypic detection of extended-spectrum β-lactamase and carbapenemase enzymes was performed by double-disc synergy test and modified Hodge test, respectively. PCR assay further investigated resistant isolates for extended-spectrum β-lactamase and carbapenemase-encoding genes.

RESULTS

The highest and lowest resistance rates were observed against ampicillin (93.3%) and tigecycline (9.3%). According to phenotypic tests, 46.7% of isolates were positive for extended-spectrum β-lactamase enzymes and 52.8% for carbapenemase. A total of 11 isolates contained carbapenemase genes, with blaOXA-48 (19.4%; 7/36) being the predominant gene, followed by blaNDM (8.3%; 3/36).

CONCLUSION

The study's findings reveal the alarming prevalence of beta-lactamase enzymes in K. pneumoniae strains. Early detection of carbapenem-resistant isolates and effective infection control measures are necessary to minimise further spread, as carbapenem resistance has become a public health concern.

Emergence of an Extensive Drug Resistant Citrobacter portucalensis Clinical Strain Harboring bla SFO-1, bla KPC-2, and bla NDM-1

Background

To explore the plasmid characteristics and transfer mechanisms of an extensive drug resistant (XDR) clinical isolate, Citrobacter portucalensis L2724hy, co-producing bla SFO-1, bla NDM-1, and bla KPC-2.

Methods

Species confirmation of L2724hy was achieved through 16S rRNA sequencing and Average Nucleotide Identity (ANI) analysis. Antimicrobial susceptibility testing (AST) employed the agar dilution and micro broth dilution methods. Identification of resistance genes was carried out by PCR and whole-genome sequencing (WGS). Essential resistance gene locations were verified by S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) and southern hybridization experiments. Subsequent WGS data analysis delved into drug resistance genes and plasmids.

Results

The confirmation of the strain L2724hy as an extensive drug-resistant Citrobacter portucalensis, resistant to almost all antibiotics tested except polymyxin B and tigecycline, was achieved through 16S rRNA sequencing, ANI analysis and AST results. WGS and subsequent analysis revealed L2724hy carrying bla SFO-1, bla NDM-1, and bla KPC-2 on plasmids of various sizes. The uncommon ESBL gene bla SFO-1 coexists with the fosA3 gene on an IncFII plasmid, featuring the genetic environment IS26-fosA3-IS26-ampR-bla SFO-1-IS26. The bla NDM-1 was found on an IncX3 plasmid, coexisting with bla SHV-12, displaying the sequence IS5-IS3000-IS3000-Tn2-bla NDM-1-ble-trpF-dsbD-cutA-gros-groL, lacking ISAa125. The bla KPC-2 is located on an unclassified plasmid, exhibiting the sequence Tn2-tnpR-ISKpn27-bla KPC-2-ISKpn6-korC. Conjugation assays confirmed the transferability of both bla NDM-1 and bla KPC-2.

Conclusion

We discovered the coexistence of bla SFO-1, bla NDM-1, and bla KPC-2 in C. portucalensis for the first time, delving into plasmid characteristics and transfer mechanisms. Our finding highlights the importance of vigilant monitoring of drug-resistance genes and insertion elements in uncommon strains.

Molecular characterization of carbapenem-resistance in Gram-negative isolates obtained from clinical samples at Jimma Medical Center, Ethiopia

Background

In resource-constrained settings, limited antibiotic options make treating carbapenem-resistant bacterial infections difficult for healthcare providers. This study aimed to assess carbapenemase expression in Gram-negative bacteria isolated from clinical samples in Jimma, Ethiopia.

Methods

A cross-sectional study was conducted to assess carbapenemase expression in Gram-negative bacteria isolated from patients attending Jimma Medical Center. Totally, 846 Gram-negative bacteria were isolated and identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Phenotypic antibiotic resistance patterns were determined using the Kirby-Bauer disk diffusion method and Etest strips. Extended-spectrum β-lactamase phenotype was determined using MAST disks, and carbapenemases were characterized using multiplex polymerase chain reactions (PCR).

Results

Among the isolates, 19% (157/846) showed phenotypic resistance to carbapenem antibiotics. PCR analysis revealed that at least one carbapenemase gene was detected in 69% (107/155) of these strains. The most frequently detected acquired genes were blaNDM in 35% (37/107), blaVIM in 24% (26/107), and blaKPC42 in 13% (14/107) of the isolates. Coexistence of two or more acquired genes was observed in 31% (33/107) of the isolates. The most common coexisting acquired genes were blaNDM + blaOXA-23, detected in 24% (8/33) of these isolates. No carbapenemase-encoding genes could be detected in 31% (48/155) of carbapenem-resistant isolates, with P. aeruginosa accounting for 85% (41/48) thereof.

Conclusion

This study revealed high and incremental rates of carbapenem-resistant bacteria in clinical samples with various carbapenemase-encoding genes. This imposes a severe challenge to effective patient care in the context of already limited treatment options against Gram-negative bacterial infections in resource-constrained settings.

Distribution of ß-Lactamase Genes Among Multidrug-Resistant and Extended-Spectrum ß-Lactamase-Producing Diarrheagenic Escherichia coli from Under-Five Children in Ethiopia

Purpose

Escherichia coli strains that produce extended-spectrum ß-lactamase (ESBL) and carbapenemase are among the major threats to global health. The objective of the present study was to determine the distribution of ß-lactamase genes among multidrug-resistant (MDR) and ESBL-producing Diarrheagenic E. coli (DEC) pathotypes isolated from under-five children in Ethiopia.

Patients and Methods

A cross-sectional study was conducted in Addis Ababa and Debre Berhan, Ethiopia. It was a health-facility-based study and conducted between December 2020 and August 2021. A total of 476 under-five children participated in the study. DEC pathotypes were detected by conventional Polymerase Chain Reaction (PCR) assay. After evaluating the antimicrobial susceptibility profile of the DEC strains by disk diffusion method, confirmation test was done for ESBL and carbapenemase production. ß-lactamase encoding genes were identified from phenotypically ESBLs and carbapenemase positive DEC strains using PCR assay.

Results

In total, 183 DEC pathotypes were isolated from the 476 under-five children. Seventy-nine (43%, 79/183) MDR-DEC pathotypes were identified. MDR was common among enteroaggregative E. coli (EAEC) (58%, 44/76), followed by enterotoxigenic E. coli (ETEC) (44%, 17/39)) and enteroinvasive E. coli (EIEC) (30%, 7/23). Phenotypically, a total of 30 MDR-DEC pathotypes (16.4%, 30/183) were tested positive for ESBLs. Few ETEC (5.1%, 2/39) and EAEC (2.6%, 2/76) were carbapenemase producers. The predominant β-lactamase genes identified was blaTEM (80%, 24/30) followed by blaCTX-M (73%, 22/30), blaSHV (60%, 18/30), blaNDM (13%, 4/30), and blaOXA-48 (13%, 4/30). Majority of the ß-lactamase encoding genes were detected in EAEC (50%) and ETEC (20%). Co-existence of different β-lactamase genes was found in the present study.

Conclusion

The blaTEM, blaCTX-M, blaSHV, blaNDM, and blaOXA-48, that are associated with serious and urgent threats globally, were detected in diarrheagenic E. coli isolates from under-five children in Ethiopia. This study also revealed the coexistence of the β-lactamase genes.

Drug resistance and extended-spectrum β-lactamase (ESBLs) - producing Enterobacteriaceae, Acinetobacter and Pseudomonas species from the views of one-health approach in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Although antimicrobial resistance (AMR) bacteria present a significant and ongoing public health challenge, its magnitude remains poorly understood, especially in many parts of the developing countries. Hence, this review was conducted to describe the current pooled prevalence of drug resistance, multidrug- resistance (MDR), and Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, Acinetobacter, and Pseudomonas species in humans, the environment, and animals or food of animal origin in Ethiopia.

METHODS

PubMed, Google Scholar, and other sources were searched for relevant articles as per the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. A critical appraisal for screening, eligibility, and inclusion in the meta-analysis was made based on the Joanna Briggs Institute's (JBI) essential appraisal tools. The meta-analysis was done on Statistical Software Package (STATA) version 17.0.

RESULTS

A total of 33 research articles were included in this systematic review and meta-analysis. Escherichia coli, Klebsiella species, Acinetobacter, and Pseudomonas species were the most frequently reported bacteria from two or more sources. More than 50% of Klebsiella species and 25% to 89% of Escherichia coli from two or more sources were resistant to all analysed antibiotics, except carbapenems. Fifty-five percent (55%) to 84% of Acinetobacter species and 33% to 79% of Pseudomonas species from human and environmental sources were resistant to all analyzed antibiotics. Carbapenem resistance was common in Acinetobacter and Pseudomonas species (38% to 64%) but uncommon in Enterobacteriaceae (19% to 44%). Acinetobacter species (92%), Klebsiella species (86%), and Pseudomonas species (79%) from human sources, and Proteus species (92%), and Acinetobacter species (83%), from environmental sources, were the common multidrug-resistant isolates. About 45% to 67% of E. coli, Klebsiella, Acinetobacter, and Pseudomonas species from human and environmental sources were ESBL producers.

CONCLUSION

Our review report concluded that there was a significant pooled prevalence of drug resistance, MDR, and ESBL-producing Enterobacteriaceae, Acinetobacter, and Pseudomonas species from two or more sources. Hence, our finding underlines the need for the implementation of integrated intervention approaches to address the gaps in reducing the emergence and spread of antibiotic- resistant bacteria.

Antimicrobial Resistance Patterns and Risk Factors Associated with ESBL-Producing and MDR Escherichia coli in Hospital and Environmental Settings in Lusaka, Zambia: Implications for One Health, Antimicrobial Stewardship and Surveillance Systems

Antimicrobial resistance (AMR) is a public health problem threatening human, animal, and environmental safety. This study assessed the AMR profiles and risk factors associated with Escherichia coli in hospital and environmental settings in Lusaka, Zambia. This cross-sectional study was conducted from April 2022 to August 2022 using 980 samples collected from clinical and environmental settings. Antimicrobial susceptibility testing was conducted using BD PhoenixTM 100. The data were analysed using SPSS version 26.0. Of the 980 samples, 51% were from environmental sources. Overall, 64.5% of the samples tested positive for E. coli, of which 52.5% were from clinical sources. Additionally, 31.8% were ESBL, of which 70.1% were clinical isolates. Of the 632 isolates, 48.3% were MDR. Most clinical isolates were resistant to ampicillin (83.4%), sulfamethoxazole/trimethoprim (73.8%), and ciprofloxacin (65.7%) while all environmental isolates were resistant to sulfamethoxazole/trimethoprim (100%) and some were resistant to levofloxacin (30.6%). The drivers of MDR in the tested isolates included pus (AOR = 4.6, CI: 1.9-11.3), male sex (AOR = 2.1, CI: 1.2-3.9), and water (AOR = 2.6, CI: 1.2-5.8). This study found that E. coli isolates were resistant to common antibiotics used in humans. The presence of MDR isolates is a public health concern and calls for vigorous infection prevention measures and surveillance to reduce AMR and its burdens.

Prevalence of carbapenemase-producing Enterobacteriaceae from human clinical samples in Ethiopia: a systematic review and meta-analysis

INTRODUCTION

Carbapenemase-producing Enterobacteriaceae are by far the most public health and urgent clinical problems with antibiotic resistance. They cause longer hospital stays, more expensive medical care, and greater mortality rates. This systematic review and meta-analysis aimed to indicate the prevalence of carbapenemase-producing Enterobacteriaceae in Ethiopia.

METHODS

This systematic review and meta-analysis was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Electronic databases like PubMed, Google Scholar, CINAHL, Wiley Online Library, African Journal Online, Science Direct, Embase, ResearchGate, Scopus, and the Web of Sciences were used to find relevant articles. In addition, the Joanna Briggs Institute quality appraisal tool was used to assess the quality of the included studies. Stata 14.0 was used for statistical analysis. Heterogeneity was assessed by using Cochran's Q test and I² statistics. In addition, publication bias was assessed using a funnel plot and Egger's test. A random effect model was used to estimate the pooled prevalence. Sub-group and sensitivity analysis were also done.

RESULTS

The overall pooled prevalence of carbapenemase-producing Enterobacteriaceae in Ethiopia was 5.44% (95% CI 3.97, 6.92). The prevalence was highest [6.45% (95% CI 3.88, 9.02)] in Central Ethiopia, and lowest [(1.65% (95% CI 0.66, 2.65)] in the Southern Nations and Nationalities People Region. In terms of publication year, 2017-2018 had the highest pooled prevalence [17.44 (95% CI 8.56, 26.32)] and 2015-2016 had the lowest [2.24% (95% CI 0.87, 3.60)].

CONCLUSION

This systematic review and meta-analysis showed a high prevalence of carbapenemase-producing Enterobacteriaceae. So, to alter the routine use of antibiotics, regular drug susceptibility testing, strengthening the infection prevention approach, and additional national surveillance on the profile of carbapenem resistance and their determining genes among Enterobacteriaceae clinical isolates are required.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (2022: CRD42022340181).

Distribution of mcr-1 Harboring Hypervirulent Klebsiella pneumoniae in Clinical Specimens and Lytic Activity of Bacteriophage KpnM Against Isolates

Background

The World Health Organization (WHO) has declared the multi-drug resistant (MDR) Klebsiella pneumoniae as one of the critical bacterial pathogens. The dearth of new antibiotics and inadequate therapeutic options necessitate finding alternative options. Bacteriophages are known as enemies of bacteria and are well-recognized to fight MDR pathogens.

Methods

A total of 150 samples were collected from different clinical specimens through a convenient sampling technique. Isolation, identification, and antibiotic susceptibility testing (AST) of K. pneumoniae were done by standard and validated microbiological procedures. Molecular identification of virulence factors and antibiotic resistance genes (ARGs) was carried out through polymerase chain reaction (PCR) by using specific primers. For bacteriophage isolation, hospital sewage samples were processed for phage enrichment, purification, and further characterization ie, transmission electron microscopy (TEM) and stability testing, etc. followed by evaluation of the lytic potential of the phage.

Results

Overall, a total of 41% of isolates of K. pneumoniae were observed as hypervirulent K. pneumoniae (hvKp). Among hvKp, a total of 12 (42%) were detected as MDR hvKp. A total of 37% of all MDR isolates were found resistant to colistin, and 66% of the colistin resistance isolates were recorded as mcr-1 positive. Isolated phage KpnM had shown lytic activity against 53 (79%) K. pneumoniae isolates. Remarkably, all 8 mcr-1 harboring MDR hvKp and non-hvKp isolates were susceptible to KpnM phage.

Conclusion

Significant distribution of mcr-1 harboring hypervirulent Klebsiella pneumoniae was observed in clinical specimens, which is worrisome for the health system of the country. Characterized phage KpnM exhibited encouraging results and showed the lytic activity against the mcr-1 harboring hvKp isolates, which may be used as a prospective alternative control strategy to fight this ominous bacterium.