Hospital surfaces can harbour bacterial pathogens, which may disseminate and cause nosocomial infections, contributing towards mortality in low- and middle-income countries (LMICs). During the BARNARDS study, hospital surfaces from neonatal wards were sampled to assess the degree of environmental surface and patient care equipment colonisation by Gram-negative bacteria (GNB) carrying antibiotic resistance genes (ARGs). Here, we perform PCR screening for extended-spectrum β-lactamases (bla_CTX-M-15) and carbapenemases (bla_NDM, bla_OXA-48-like and bla_KPC), MALDI-TOF MS identification of GNB carrying ARGs, and further analysis by whole genome sequencing of bacterial isolates. We determine presence of consistently dominant clones and their relatedness to strains causing neonatal sepsis. Higher prevalence of carbapenemases is observed in Pakistan, Bangladesh, and Ethiopia, compared to other countries, and are mostly found in surfaces near the sink drain. Klebsiella pneumoniae, Enterobacter hormaechei, Acinetobacter baumannii, Serratia marcescens and Leclercia adecarboxylata are dominant; ST15 K. pneumoniae is identified from the same ward on multiple occasions suggesting clonal persistence within the same environment, and is found to be identical to isolates causing neonatal sepsis in Pakistan over similar time periods. Our data suggests persistence of dominant clones across multiple time points, highlighting the need for assessment of Infection Prevention and Control guidelines.

Streptococcus agalactiae or group B streptococcus (GBS) is a leading cause of neonatal sepsis and increasingly found as an invasive pathogen in older patient populations. Beta-lactam antibiotics remain the most effective therapeutic with resistance rarely reported, while the majority of GBS isolates carry the tetracycline resistance gene tet(M) in fixed genomic positions amongst five predominant clonal clades. In the UK, GBS resistance to clindamycin and erythromycin has increased from 3% in 1991 to 11.9% (clindamycin) and 20.2% (erythromycin), as reported in this study. Here, a systematic investigation of antimicrobial resistance genomic content sought to fully characterise the associated mobile genetic elements within phenotypically resistant GBS isolates from 193 invasive and non-invasive infections of UK adult patients collected during 2014 and 2015. Resistance to erythromycin and clindamycin was mediated by erm(A) (16/193, 8.2%), erm(B) (16/193, 8.2%), mef(A)/msr(D) (10/193, 5.1%), lsa(C) (3/193, 1.5%), lnu(C) (1/193, 0.5%), and erm(T) (1/193, 0.5%) genes. The integrative conjugative elements (ICEs) carrying these genes were occasionally found in combination with high gentamicin resistance mediating genes aac(6′)-aph(2″), aminoglycoside resistance genes (ant(6-Ia), aph(3′-III), and/or aad(E)), alternative tetracycline resistance genes (tet(O) and tet(S)), and/or chloramphenicol resistance gene cat(Q), mediating resistance to multiple classes of antibiotics. This study provides evidence of the retention of previously reported ICESag37 (n = 4), ICESag236 (n = 2), and ICESpy009 (n = 3), as well as the definition of sixteen novel ICEs and three novel transposons within the GBS lineage, with no evidence of horizontal transfer.

A mobile colistin resistance gene mcr was first reported in 2016 in China and has since been found with increasing prevalence across South-East Asia. Here we survey the presence of mcr genes in 4907 rectal swabs from mothers and neonates from three hospital sites across Nigeria; a country with limited availability or history of colistin use clinically. Forty mother and seven neonatal swabs carried mcr genes in a range of bacterial species: 46 Enterobacter spp. and single isolates of; Shigella, E. coli and Klebsiella quasipneumoniae. Ninety percent of the genes were mcr-10 (n = 45) we also found mcr-1 (n = 3) and mcr-9 (n = 1). While the prevalence during this collection (2015-2016) was low, the widespread diversity of mcr-gene type and range of bacterial species in this sentinel population sampling is concerning. It suggests that agricultural colistin use was likely encouraging sustainment of mcr-positive isolates in the community and implementation of medical colistin use will rapidly select and expand resistant isolates.

The dissemination of antimicrobial resistant (AMR) bacteria by flies in hospitals is concerning as nosocomial AMR infections pose a significant threat to public health. This threat is compounded in low- and middle-income countries (LMICs) by several factors, including limited resources for sufficient infection prevention and control (IPC) practices and high numbers of flies in tropical climates. In this pilot study, 1,396 flies were collected between August and September 2022 from eight tertiary care hospitals in six cities (Abuja, Enugu, Kaduna, Kano, Lagos and Sokoto) in Nigeria. Flies were screened via microbiological culture and bacterial isolates were phenotypically and genetically characterised to determine carriage of clinically important antibiotic resistance genes (ARGs). Several clinically relevant ARGs were found in bacteria isolated from flies across all hospitals. bla_NDM was detected in 8% of flies and was predominantly carried by Providencia spp. alongside clinically relevant Enterobacter spp, Escherichia coli and Klebsiella pneumoniae isolates, which all exhibited a multidrug resistant phenotype. mecA was detected at a prevalence of 6.4%, mostly in coagulase-negative Staphylococci (CoNS) as well as some Staphylococcus aureus, of which 86.8% were multidrug resistant. 40% of flies carried bacteria with at least one of the two ESBL genes tested (bla_OXA-1 and bla_CTX-M-15). This multi-site study emphasised that flies in hospital settings carry bacteria that are resistant to multiple classes of antibiotics, including both routinely used and reserve antibiotics. A greater understanding of the global clinical significance and burden of AMR attributable to insect pests is required.

Background: Streptococcus agalactiae (Group B Streptococcus, GBS) is a leading cause of neonatal sepsis in high-income countries. While intrapartum antibiotic screening reduces this risk, increasing resistance to macrolides and lincosamides in Europe since the 1990s has limited therapeutic options for penicillin-allergic patients. Reports of reduced beta-lactam susceptibility in GBS further emphasise the need for robust antimicrobial resistance (AMR) surveillance. However, broth microdilution (BMD) methods are unsuitable for large-scale antimicrobial susceptibility testing (AST). Objective: To demonstrate that agar-dilution AST provides equivalent results to broth dilution methods, with superior capacity for high-throughput screening. Methods: Agar-dilution and microdilution AST methods were compared using a panel of 24 characterised susceptible and resistant GBS strains for benzylpenicillin, chloramphenicol, clindamycin, erythromycin, gentamicin, levofloxacin, tetracycline, and vancomycin. Minimum inhibitory concentration (MIC) agreements were evaluated, and resistance profile correlations were assessed using Cohen’s kappa values. Results: Agar-dilution demonstrated >90% agreement with BMD MIC for most antimicrobials, except vancomycin (87.5%), erythromycin (83.33%), and tetracycline (52.78%). Cohen’s kappa values indicated strong agreement (0.88–1.00) for resistance determination. Agar-dilution avoided “trailing growth” issues associated with BMD and facilitated easier detection of non-GBS contaminants. Conclusions: Agar-dilution is a valid method for high-throughput AMR surveillance of retrospective cohorts (96 isolates per plate) and is critical for identifying emerging GBS resistance trends and informing therapeutic guidelines. However, due to the large number of plates required per antimicrobial, it is impractical for routine clinical diagnostics.