Molecular characterisation of extended-spectrum β-lactamase-producing Gram-negative bacterial isolates from surgical wounds of patients at a hospital in North Central Nigeria

Frequency of Fecal Carriage of ESBL Resistance Genes in Multidrug-Resistant Pseudomonas aeruginosa Isolates from Cancer Patients at Laquintinie Hospital, Douala, Littoral Region, Cameroon

Background. Opportunistic infections are the second cause of death among cancer patients. This study aimed at determining the antimicrobial profile and the prevalence of extended-spectrum beta-lactamase (ESBL)-gene carriage of Pseudomonas aeruginosa isolates among cancer patients at the Douala Laquintinie Hospital, Littoral Region of Cameroon. Between October 2021 and March 2023, 507 study participants were recruited among whom 307 (60.55%) were cancer patients, compared to 200 (39.45%) noncancer patients. Fifty-eight P. aeruginosa isolates were isolated from fecal samples of forty-five cancer patients and thirteen noncancer patients using Cetrimide agar. The antimicrobial resistance profile of the isolates was determined using the Kirby-Bauer disk diffusion method. The polymerase chain reaction was used to detect the presence of extended-spectrum beta-lactamase genes among P. aeruginosa isolates. P. aeruginosa showed significant resistance rates in cancer patients compared to noncancer patients to imipenem, cefotaxime, and ceftazidime, piperacillin-tazobactam, ticarcillin-clavulanic acid, and ciprofloxacin. The multidrug resistance (MDR) rate was significantly (p < 0.05) higher in cancer patients than in noncancer patients. The frequency of beta-lactamase genes in the 58 ESBL-producing P. aeruginosa isolates was determined as 72.41% for bla TEM, 37.93% for bla OXA, 74.14% for blaCTX-M, and 44.83% for bla SHV genes. The study revealed an alarmingly high prevalence of fecal carriage of ESBL-producing P. aeruginosa with a high rate of MDR among cancer patients. It indicates that regular monitoring and surveillance of ESBL-producing P. aeruginosa among cancer patients are needed to improve the management of patients.

Phylogenetic Characterization of Resistant Salmonella Strains in Typhoid Fever Patients in Nigeria

Salmonella species are Enterobacteriaceae associated with typhoid fever. In this study, the distribution of broad-spectrum β-lactamase regulatory genes and genetic relatedness of isolates was determined. Stool samples (400) were collected from patients with fever in Dalhatu Araf Specialist Hospital (DASH), Lafia, Nigeria, between March 2020 and April 2021. Salmonella species were isolated and extended-spectrum β-lactamase distribution was determined among resistant isolates using polymerase chain reaction (PCR). Genetic relatedness of Salmonella species resistant to the 10 first-line antibiotics administered was determined among S typhi isolated. Of the 60 isolates that were confirmed to belong to the genus Salmonella, 12 (20.0%) isolates with bla SHV genes were the most prevalent, blaOXA-1 and blaCTX-M-9 were present in 5 isolates each, while blaCTX-M-4 and blaTEM genes with a prevalence of 1.7% each were the least obtained in the isolates. Two isolates had a multidrug-resistant index (MDRI) of 1, and 2 others were positive with the S typhi staG gene. Sequencing to determine their diversity showed that isolates ST36 and ST138, respectively, had MDRI = 1 and are clustered in a group with a similarity coefficient of 0.00634. The 2 isolates had the highest genetic similarity, which indicates that the genetic diversity between the isolates is low, while Salmonella strain ST313L2 had a high level of genetic distance from the other isolates. The most resistant isolates are closely related which calls for concern.

Beta-lactamase resistance genes in Enterobacteriaceae from Nigeria

Background

Beta-lactamase genes are one of the most important groups of antimicrobial resistance genes in human and animal health. Therefore, continuous surveillance of this group of resistance genes is needed for a better understanding of the local epidemiology within a country and global dissemination.

Aim

This review was carried out to identify different beta-lactamase resistance genes reported in published literature from Nigeria.

Methods

Systematic review and meta-analysis was carried out on eligible Nigerian articles retrieved from electronic literature searches of PubMed^®, African Journals Online, and Google Scholar published between January 1990 and December 2019. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses method was adopted to facilitate clarity and transparency in reporting review findings.

Results

Fifty-seven articles were included. All beta-lactamases reported were detected from Gram-negative bacteria, particularly from Enterobacteriaceae. Thirty-six different beta-lactamase genes were reported in Nigeria. These genes belong to the narrow-spectrum, AmpC, extended-spectrum and carbapenemase beta-lactamase resistance genes. The pooled proportion estimate of extended-spectrum beta-lactamase genes in Nigeria was 31% (95% confidence interval [CI]: 26% – 36%, p < 0.0001), while the estimate of the bla_CTX-M-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).

Conclusion

This study provides information on beta-lactamase 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.

Emergence of bla TEM, bla CTX-M, bla SHV and bla OXA genes in multidrug-resistant Enterobacteriaceae and Acinetobacter baumannii in Saudi Arabia

Multidrug-resistant (MDR) patterns due to extended-spectrum β-lactamase (ESBL) production in pathogenic bacteria are now becoming prevalent in hospitals worldwide, posing a public health challenge. The aim of the present study was to determine the antibiotic susceptibility patterns and distribution of the bla _TEM, bla _CTX-M, bla _SHV and bla _OXA ESBL resistance genes in MDREnterobacteriaceae and Acinetobacter baumannii (A. baumannii). A cross-sectional study was conducted between September 2017 and August 2018 in the King Abdullah Hospital (Bisha, Saudi Arabia). Bacterial isolates were collected from the clinical samples of patients; these were identified and screened for ESBL production and their antibiotic susceptibility was examined using standard microbiology methods. Multiplex-PCR runs were performed to identify genes encoding ESBL producers. DNA sequencing analysis was used to identify the specific gene variants. Of the 274 isolates, 173 (63.1%) exhibited MDR patterns to different antibiotics. A. baumannii revealed the highest resistance rates for cefuroxime (100%), gentamicin (88%) and amikacin (86%). Klebsiella pneumoniae (K. pneumoniae) isolates had the highest resistance rates for cefuroxime (98%), aztreonam and trimethoprim/sulfamethoxazole (87% for each). Escherichia coli (E. coli) exhibited high resistance rates for trimethoprim/sulfamethoxazole (92%) and cefuroxime (87%). Of the 173 MDR isolates, 78 (45.1%) exhibited ESBL production. Of these, 88.9% (72/78) carried ESBL genes. The most prevalent gene-encoding isolates were bla _TEM (84.7%), followed by bla _CTX-M (33.3%), bla _SHV (2.7%) and bla _OXA-1 (1.4%). A single bla _TEM gene was predominantly produced by K. pneumoniae (60.7%), A. baumannii (78.9%) and Proteus mirabilis (80%), whereas bla _CTX-M was harbored by E. coli (33.3%). The co-existence of two different genes in a single bacterium was revealed in 22.2% of isolates, commonly between bla _TEM and bla _CTX-M (19.4%). Sequencing analysis revealed that bla _CTX-M-15 and bla _TEM-1 were predominant variants of the bla _CTX-M and bla _TEM genes, respectively. The present study revealed a diversity of ESBL genes in Gram-negative bacterial isolates, with bla _TEM being the most prevalent type. The emergence of various ESBL genes with several co-existing genotypes is alarming, rendering extensive surveillance studies necessary to understand the transmission and epidemiology of such resistant gene-carrying isolates.

Prevalence of extended-spectrum β-lactamase (ESBL) and molecular detection of blaTEM, blaSHV and blaCTX-M genotypes among Enterobacteriaceae isolates from patients in Khartoum, Sudan

Introduction

the emergence of antibiotic resistance pathogens is an important health risk. Usually Gram negative bacteria acquire resistance to beta-lactam antibiotics by beta-lactamase production. The objectives of this study was to assess the prevalence of ESBL and to detect the frequency of blaTEM, blaSHV and blaCTX-M genotypes among ESBL producing Enterobacteriaceae isolates from patients in Khartoum, Sudan.

Methods

a total of 171 isolates of Enterobacteriaceae were recovered from hospitals in Khartoum, Sudan (2014 -2015) were used to detect ESBL production using disc diffusion method. blaTEM, blaSHV and blaCTX-M genes were investigated by PCR based methods using gene-specific primers.

Results

the high resistance among Enterobacteriaceae was noticed in ciprofloxacin (72%) and ofloxacin (73%). ESBL production was mainly in Escherichia Coli (38%) and Klebsiella pneumonia (34%). Prevalent genotypes were blaTEM (86%), blaCTX-M (78%) and blaSHV (28%). These were found mainly in Escherichia Coli (38%, 37%, 2%) and K. pneumonia (34%, 31%, 26.1%). The majority of ESBL producing isolates possess more than one ESBL genes.

Conclusion

the ESBL production in Enterobacteriaceae was high, with blaTEM and blaCTX-M genotypes more prevalent. Public health and laboratory standard of excellence is needed to reducing the spread of resistant pathogens.

First whole genome sequence of Paenalcaligenes suwonensis bearing blaVIM-5 Metallo-β-lactamase: A clinical isolate responsible for acute gastroenteritis

Carbapenemase-producing Alcaligenes species has been described in only few studies, with none so far from the African continent. Here, we report the whole genome sequence of Peanalcaligenes suwonensis bearing bla_VIM-5 metallo-β-lactamase and first detection of carbapenemase producing Alcaligenes faecalis isolated from patients attending tertiary healthcare facilities in Nigeria. The isolates were identified by MALDI-TOF Mass Spectrometry. Antibiotic susceptibility assay, modified Carba NP test and genomic investigation revealed that two isolates of Alcaligenes faecalis and an isolate of Paenalcaligenes suwonensis harboured bla_VIM-5 gene. The genome sequence analysis of the P. suwonensis 191B isolate, responsible for acute gastroenteritis, reveal the presence of 18 antibiotic resistance genes coding for resistance to five different classes of antibiotics. Three of the genes (bla_OXA-368, bla_CARB-4 and bla_VIM-5) codes for resistance to β-lactam antibiotics. To our best knowledge, we describe here the first genome sequence of P. suwonensis species and the first detection of class B carbapenemase bla_VIM-5 in a clinical isolate of P. suwonensis species and Alcaligenes faecalis in Nigeria. The finding of this study is of concern, as lateral dissemination of the genes into clinically important Gram-negative pathogens is highly likely.

A systematic review on the prevalence of extended-spectrum beta lactamase-producing Gram-negative bacteria in Nigeria

OBJECTIVE

There are numerous reported cases of extended-spectrum beta-lactamases (ESBLs) producing Enterobacteriaceae in Nigeria. Yet, there are regions in Nigeria where cases of ESBL were under-reported. The review aims to assess the prevalence of ESBL-producing Gram-negative bacteria in Nigeria and the genes involved.

METHODS

An extensive literature search was carried out through an electronic database including PubMed, Scopus, Google Scholar and African Journals Online (AJOL). Articles published between January 2004 and November 2019 were included in the study. The titles and abstracts of the retrieved articles were reviewed, and then the full texts of the selected articles were reviewed. Articles were divided according to geopolitical zones.

RESULTS

Among the 217 articles identified, 60 studies (10 from north-central, 4 from northeast, 7 from the northwest, 17 from the southeast, 10 from south-south, and 12 from southwest Nigeria) were included. The highest prevalence recorded was 82.3%, while the lowest was 7.5%. The genes TEM, SHV, and CTX-M were the predominant variant commonly found. The most frequently used phenotypic detection method is the double disc synergy test (DDST).

CONCLUSION

ESBL-producing Gram-negative bacteria in hospital and community settings in Nigeria were commonly found. The prevalence of ESBL is very high, with one of the geopolitical zones under-reported. Future research should be conducted in these zones where there are scant studies, and a holistic approach involving the clinicians, researchers, laboratory scientists, and patients will go a long way in reducing the dissemination of this resistance mechanism.

The burden of extended-spectrum β-lactamase-producing Enterobacteriaceae in Nigeria: a systematic review and meta-analysis

Antibiotic resistance on account of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) has become a major public health concern in developing countries. The presence of ESBL-PE is associated with increased morbidity, mortality and healthcare costs. There is no active antimicrobial surveillance mechanism in Nigeria. The aim of this study is to determine a precise estimate of the burden of ESBL-PE in Nigeria. We employed Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and searched electronic databases for suitable studies. We derived pooled prevalence estimates using random effects models and assessed trends with meta-regression. We found 208 studies, with 38 satisfying our inclusion criteria. The overall pooled prevalence of ESBL-PE in Nigeria was 34.6% (95% CI 26.8 to 42.3%) and increased at a rate of 0.22% per year (p for trend=0.837). In summary, we found the prevalence of ESBL-PE in Nigeria to be high and recommend a robust national survey to provide a more detailed picture of the epidemiology of ESBL-PE in Nigeria.

Epidemiology of surgical site infections in Nigeria: A systematic review and meta-analysis

Introduction

Surgical site infection (SSI) is a major patient safety concern in hospitals. Unlike most developed countries, Nigeria does not yet have an established national system to monitor the occurrence of this infection. This meta-analysis was thus designed to determine the pooled cumulative incidence of SSIs and various determinants of its occurrence in Nigeria.

Methods

The electronic databases were systematically searched for articles reporting the occurrence and risk factors associated with SSIs in Nigeria from January 2000 to December 2018. The eligible articles were evaluated using a set of pre-defined criteria. The extracted data were analysed using the comprehensive meta-analysis software. The Begg and Egger's regression tests were used to assess the risk of bias of the included publications.

Results

Thirty-two articles emanating from the six geopolitical regions of Nigeria were included in this meta-analysis. The pooled cumulative incidence of SSIs was 14.5% (95% confidence interval [CI]: 0.113-0.184) with the highest incidence reported in the north-eastern region (27.3%, 95% CI: 0.132-0.481) of the country. It was also found to occur more predominantly following colorectal and abdominal surgeries, among elderly patients and in patients with co-morbid conditions. The most frequently reported was the superficial incisional SSIs occurring in 62.5% (95% CI: 0.333-0.848). Higher preponderance was also observed among patients with dirty wounds (52.7%, 95% CI: 0.367-0.682).

Conclusion

This meta-analysis documents for the first time the national burden of SSIs in Nigeria. Control measures geared towards its reduction should be strengthened and a national policy on SSI surveillance, prevention and control developed.

Treating drug-resistant wound pathogens with non-medicated dressings: an in vitro study

Objective:

To assess the in vitro antimicrobial performance of a non-medicated hydro-responsive wound dressing (HRWD) on the sequestration and killing of wound relevant microorganisms found on the World Health Organization (WHO) priority pathogens list.

Methods:

Suspensions of Pseudomonas aeruginosa, Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus (MRSA) were placed on petri dishes. Dressings were each placed on top, incubated for 30 minutes and then removed from the inoculated petri dish. The surface of the dressings previously in contact with the bacterial suspensions were placed directly onto a tryptone soy agar (TSA) plate and incubated for 24 hours. Dressings were then removed from the TSA plate and the level of bacterial growth on the plates was assessed. Sequestered microorganism viability was assessed using LIVE/DEAD viability kits and visualisation by epifluorescence.

Results:

Our results indicated that HRWDs sequester and retain Pseudomonas aeruginosa, Acinetobacter baumannii and MRSA within the dressing. Non-medicated HRWDs containing bound PHMB (polyhexamethylene biguanide, HRWD+PHMB) killed the microorganisms sequestered within the dressing matrix.

Conclusion:

These data suggest that non-medicated HRWD+PHMB is an effective against WHO priority pathogens and promoting goal of antimicrobial stewardship in wound care.

Analysis of Clinical Isolates of Extended-Spectrum β-Lactamase-Producing Bacteria with Primer and Probe Sets Developed to Detect blaCTX-M, blaTEM, and blaSHV Using a Fully Automated Gene Detection System

In this study, we evaluated extended-spectrum β-lactamase (ESBL)-producing bacteria with the newly developed primer and probe sets to detect bla_CTX-M, bla_TEM, and bla_SHV using BD MAX^TM, a fully automated multiplex polymerase chain reaction assay system. In 36 isolates confirmed by whole-genome sequencing to have bla_CTX-M, bla_TEM, or bla_SHV, the developed primer and probe sets accurately detected each gene without being influenced by the presence of other β-lactamase genes. In nine control strains that do not harbor either bla_CTX-M, bla_TEM, or bla_SHV no cross-reaction was observed. In 191 strains phenotypically determined to be ESBL-producers by conventional antimicrobial susceptibility tests, 189 strains were blaC_TX-M-, bla_TEM-, or bla_SHV-positive as assessed by BD MAX^TM using the developed primer and probe sets, and two strains were negative for these genes. Whole-genome sequencing revealed that these two strains were phenotypically false-positive ESBL-producers. The accuracy of the primer and probe sets seems to be satisfactory, and they may be applicable to detect CTX-M-type ESBL-producing bacteria.

Phenotypic Characterization and Antibiotic Resistance Patterns of Extended-Spectrum β-Lactamase- and AmpC β-Lactamase-Producing Gram-Negative Bacteria in a Referral Hospital, Saudi Arabia

Background

Emergence of pathogenic bacteria carrying β-lactamase-resistant determinants has become a major health problem in the hospital setting. The study aimed to determine antibiotic-resistant patterns and frequency of extended-spectrum β-lactamase- (ESBL-) producing Gram-negative bacteria (GNB) and AmpC β-lactamase-producing GNB.

Methodology

A prospective cross-sectional study was conducted during a period from September 2017 to August 2018 at King Abdullah Hospital, Bisha Province, Saudi Arabia. GNB (n = 311) were recovered from patients' clinical specimens including sputum, urine, wound pus, blood, tracheal aspirates and high vaginal swabs, umbilical discharge, eye discharge, and cerebrospinal fluids. Isolates were identified by the Phoenix identification system. Antimicrobial susceptibility was tested by the Kirby–Bauer disk procedure. Phenotypic characterization of ESBLs and AmpC β-lactamases was performed utilizing the double-disk synergy test and inhibitor-based method, respectively. Associations with outcome measures were determined by simple descriptive statistics and a chi-square test.

Results

Out of 311 GNB isolates, the frequency of ESBL and AmpC β-lactamase producers was 84 (27%) and 101 (32.5%), respectively. Klebsiella pneumoniae and Escherichia coli were common ESBL producers. AmpC β-lactamases predominate among Acinetobacter spp. and Pseudomonas aeruginosa. Coproduction of ESBLs and AmpC β-lactamases was found in 36 (11.6%) isolates, with very close relative frequencies among K. pneumoniae, Acinetobacter spp., and P. aeruginosa. β-Lactamase producers were predominantly found in the surgical department (56.5%) and ICUs (44.2%). ESBL producers revealed high resistance for cefuroxime (96.4%), cefotaxime (92.9%), and trimethoprim/sulfamethoxazole (90.5%). The resistance rates were significantly higher among ESBL producers than nonproducers for cephalosporins (p < 0.001), amoxicillin/clavulanate (p < 0.001), piperacillin/tazobactam (p = 0.010), nitrofurantoin (p = 0.027), aztreonam (p < 0.001), ciprofloxacin (p = 0.002), and trimethoprim/sulfamethoxazole (p < 0.001). Significantly higher (p < 0.05) resistance rates were observed among AmpC β-lactamase producers than nonproducers for all tested antibiotics.

Conclusions

This finding showed a high prevalence of ESBL- and AmpC β-lactamase-producing GNB in our hospital. Quality control practice and routine detection of β-lactamase producers before deciding on antibiotic therapy are advocated.

Molecular identification and structural characterization of marine endophytic actinomycetes Nocardiopsis sp. GRG 2 (KT 235641) and its antibacterial efficacy against isolated ESBL producing bacteria

The present study was designed to identify the potential bioactive compound from endophytic actinomycetes (EA) Nocardiopsis sp. GRG 2 (KT 235641) against selected extended spectrum beta lactamase (ESBL) producing Pseudomonas aeruginosa (P. aeruginosa) and Klebsiella pneumoniae (K. pneumoniae). Initially, the multi drug resistance (MDR) effect of selected uropathogens was confirmed by respective UTI panel of Hexa antibiotics disc methods. The zone of inhibition ≤22 mm for ceftazidime, ≤ 27 mm for cefotaxime and ≤8 mm zone of MIC stripe against both the uropathogens of phenotypic methods confirmed, the selected strains were ESBL producer. Among the various EA extracts, GRG 2 extract showed excellent antibacterial activity against both ESBL producing P. aeruginosa and K. pneumonia by agar well diffution method. The molecular identification of selected GRG 2 strain was named as Nocardiopsis sp. GRG 2 (KT235641). The antibacterial metabolites present in the TLC elution was exhibited at 274 nm by UV visible spectrometer. The partial purification of preparative HPLC fraction 3 showed 14, 16 mm against P. aeruginosa and K. pneumoniae, respectively. Based on the antibacterial effect, the FT-IR, GC-MS and LC-MS analysis of fraction 3 was confirmed as 1, 4-diaza-2, 5-dioxo-3-isobutyl bicyclo[4.3.0]nonane (DDIBN). Further, the dose dependent inhibition of DDIBN against both ESBL producing pathogens was observed at 75 μg/mL by minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC). The increased cell death and disrupted cell membrane integrity were observed at MIC of DDIBN by confocal laser scanning electron microscope (CLSM) and scanning electron microscope (SEM). The results were proved that the DDIBN has potential antibacterial metabolites against ESBL producing pathogens and it can be applied for various other biomedical fields.

Occurrence of Surgical Site Infections at a Tertiary Healthcare Facility in Abuja, Nigeria: A Prospective Observational Study

Surgical site infection (SSI) is one of the most frequent complications of surgical interventions. Several factors have been identified as major determinants of occurrence of SSIs. The present study determined the occurrence and possible risk factors associated with SSIs at a tertiary healthcare facility in Abuja, Nigeria. All patients scheduled for operation in the hospital during the study period and who consented to participate willingly in the study were observed prospectively for the occurrence of SSI based on criteria stipulated by the United States Centre for Disease Control and Prevention (CDC). Data on sociodemographic characteristics, lifestyle, surgical procedure and co-morbidity were collected into a pre-tested data collection tool and analysed using IBM SPSS Statistics software v.24. Predictors of SSIs were identified using multivariate logistic regression model and p-value less than 0.05 was considered statistically significant. Of the 127 surgical patients that met the inclusion criteria comprising 65 (51.2%) females and 62 (48.8%) males between 1 and 83 years with mean age of 25.64 ± 1.66 years, 35 (27.56%; 95% Confidence Interval (CI): 0.205⁻0.360) developed SSIs. Prolonged post-operative hospital stays (p < 0.05), class of wound (p < 0.0001) and some comorbid conditions were found to be significantly associated with higher SSI rate. The SSI rate was highest among patients that had Kirschner-wire insertion (75.0%), followed by an unexpectedly high infection rate among patients that had mastectomy (42.9%), while lower percentages (33.3%) were recorded among patients that had exploratory laparotomy and appendicectomy. The overall magnitude of SSIs in this facility is high (27.6%; 95% CI: 0.205⁻0.360). Several factors were found to be independent predictors of occurrence of SSI. The findings thus highlight the need for improved surveillance of SSIs and review of infection control policies of the hospital.