Clones and Clusters of Antimicrobial-Resistant Klebsiella From Southwestern Nigeria.

BACKGROUND: Klebsiella pneumoniae is a World Health Organization high-priority antibiotic-resistant pathogen. However, little is known about Klebsiella lineages circulating in Nigeria. METHODS: We performed whole-genome sequencing (WGS) of 141 Klebsiella isolated between 2016 and 2018 from clinical specimens at 3 antimicrobial-resistance (AMR) sentinel surveillance tertiary hospitals in southwestern Nigeria. We conducted in silico multilocus sequence typing; AMR gene, virulence gene, plasmid, and K and O loci profiling; as well as phylogenetic analyses, using publicly available tools and Nextflow pipelines. RESULTS: Phylogenetic analysis revealed that the majority of the 134 K. pneumoniae and 5 K. quasipneumoniae isolates from Nigeria characterized are closely related to globally disseminated multidrug-resistant clones. Of the 39 K. pneumoniae sequence types (STs) identified, the most common were ST307 (15%), ST5241 (12%), ST15 (~9%), and ST25 (~6%). ST5241, 1 of 10 novel STs detected, is a single locus variant of ST636 carrying dfrA14, tetD, qnrS, and oqxAB resistance genes. The extended-spectrum ß-lactamase (ESBL) gene blaCTX_M-15 was seen in 72% of K. pneumoniae genomes, while 8% encoded a carbapenemase. No isolate carried a combination of carbapenemase-producing genes. Four likely outbreak clusters from 1 facility, within STs 17, 25, 307, and 5241, were ESBL but not carbapenemase-bearing clones. CONCLUSIONS: This study uncovered known and novel K. pneumoniae lineages circulating in 3 hospitals in Southwest Nigeria that include multidrug-resistant ESBL producers. Carbapenemase-producing isolates remain uncommon. WGS retrospectively identified outbreak clusters, pointing to the value of genomic approaches in AMR surveillance for improving infection prevention and control in Nigerian hospitals.

Clinical and bacteriological profiles of neonatal sepsis in a tertiary hospital, south-western Nigeria.

Introduction: Antibiotic-resistant bacteria complicate treatment options in neonatal sepsis, especially in developing countries. This study determined the epidemiology and bacteriological characteristics of neonatal sepsis at a tertiary hospital, in southwest Nigeria. Methods: This was a cross-sectional study from December 2017 to April 2019 among admitted babies with clinical neonatal sepsis. Blood culture was performed by semi-automated system, sepsis biomarker assay (serum procalcitonin) by a semi-quantitative kit while proforma was used to capture clinico-demographic data. Bacterial identification, antibiotic susceptibility patterns, determination of genetic elements mediating resistance, were performed by standard methods and polymerase chain reaction protocols, respectively. Quantitative data were expressed as frequencies, mean; bivariate and multivariate analyses were performed by Chi-square or Fishers' exact test and logistic regression. Results: Of the 192 cases of neonatal sepsis enrolled, 42.7% (82/192) were blood culture positive. Factors associated with blood culture positivity included respiratory rate ≥60 bpm (60/82; p<0.03), lethargy/unconsciousness (59/82; FE=7.76; p<0.001), grunting respiration (54/82; p=0.04), meconium passage before birth (17/82; p=0.03) and prolonged rupture of membranes ≥24 hours (50/82; FE=6.90; p=0.01). On the other hand, mortality in the neonates was associated with elevated serum procalcitonin assay (>0.5 ng/mL) χ2=13.58; p=0.03] and Gram-negative bacteremia (χ2=24.64; p<0.001). The most common bacterial isolates were Staphylococcus aureus (42/82), coagulase-negative Staphylococcus spp. (17/82), Enterobacter spp. (8/82), and Acinetobacter spp. (6/82). Methicillin resistance was present in 85.7% (36/42) of Staphylococcus aureus and 52.9% (9/17) of coagulase-negative Staphylococcus, while extended-spectrum beta-lactamase (ESBL) and AmpC enzymes were present in (21.1%; 4/19) of the Gram-negative bacilli. Conclusions: Almost half of the cases of clinically diagnosed neonatal sepsis have bacterial etiologic confirmation of sepsis. Gram-negative bacteremia and high serum procalcitonin predict mortality in neonatal sepsis. There was high resistance to common antibiotics for the treatment of neonatal sepsis in our settings.

A systematic review of healthcare-associated infections in Africa: An antimicrobial resistance perspective.

BACKGROUND: Healthcare-associated infection (HCAI) is a global health challenge, not only as an issue of patient safety but also as a major driver of antimicrobial resistance (AMR). It is a major cause of morbidity and mortality with economic consequences. OBJECTIVE: This review provides an update on the occurrence of HCAI, as well as the contribution of emerging AMR on healthcare delivery in Africa. METHODS: We searched PubMed, Cochrane database, African Journals Online and Google Scholar for relevant articles on HCAI in Africa between 2010 and 2017. Preferred reporting items of systematic reviews and meta-analyses guidelines were followed for selection. Thirty-five eligible articles were considered for the qualitative synthesis. RESULTS: Of the 35 eligible articles, more than half (n = 21, 60%) were from East Africa. Klebsiella spp., Staphylococcus aureus, Escherichia coli and Pseudomonas spp. were the common pathogens reported in bloodstream infection, (catheter-associated) urinary tract infection, surgical site infection and healthcare-associated pneumonia. Among these various subtypes of HCAI, methicillin-resistant S. aureus (3.9% - 56.8%) and extended-spectrum beta-lactamase producing Gram-negative bacilli (1.9% - 53.0%) were the most reported antimicrobial resistant pathogens. CONCLUSION: This review shows a paucity of HCAI surveillance in Africa and an emergence of AMR priority pathogens. Hence, there is a need for a coordinated national and regional surveillance of both HCAI and AMR in Africa.