title: Characterization of pre-antibiotic era Klebsiella pneumoniae isolates with respect to antibiotic/disinfectant susceptibility and virulence in Galleria mellonella.
abstract: The EGD Murray collection consists of approximately 500 clinical bacterial isolates, mainly Enterobacteriaceae, isolated from around the world between 1917 and 1949. A number of these "Murray" isolates have subsequently been identified as Klebsiella pneumoniae. Antimicrobial susceptibility testing of these isolates showed that over 30% were resistant to penicillins due to the presence of diverse blaSHV β-lactamase genes. Analysis of susceptibility to skin antiseptics and triclosan showed that while the Murray isolates displayed a range of MIC/minimal bactericidal concentration (MBC) values, the mean MIC value was lower than that for more modern K. pneumoniae isolates tested. All Murray isolates contained the cation efflux gene cepA, which is involved in disinfectant resistance, but those that were more susceptible to chlorhexidine were found to have a 9- or 18-bp insertion in this gene. Susceptibility to other disinfectants, e.g., H2O2, in the Murray isolates was comparable to that in modern K. pneumoniae isolates. The Murray isolates were also less virulent in Galleria and had a different complement of putative virulence factors than the modern isolates, with the exception of an isolate related to the modern lineage CC23. More of the modern isolates (41% compared to 8%) are classified as good/very good biofilm formers, but there was overlap in the two populations. This study demonstrated that a significant proportion of the Murray Klebsiella isolates were resistant to penicillins before their routine use. This collection of pre-antibiotic era isolates may provide significant insights into adaptation in K. pneumoniae in relation to biocide susceptibility.
authors.affiliation: Public Health England, Microbiology Services Division, Salisbury, Wiltshire, United Kingdom matthew.wand@phe.gov.uk.
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Wand
authors.affiliation: Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom.
authors.forename: Kate S
authors.initials: KS
authors.lastname: Baker
authors.affiliation: Public Health England, Microbiology Services Division, Salisbury, Wiltshire, United Kingdom.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Benthall
authors.affiliation: National Collection of Type Cultures, Culture Collections, Public Health England, Salisbury, Wiltshire, United Kingdom.
authors.forename: Hannah
authors.initials: H
authors.lastname: McGregor
authors.affiliation: Public Health England, Microbiology Services Division, Salisbury, Wiltshire, United Kingdom.
authors.forename: James W I
authors.initials: JW
authors.lastname: McCowen
authors.affiliation: National Collection of Type Cultures, Culture Collections, Public Health England, Salisbury, Wiltshire, United Kingdom.
authors.forename: Ana
authors.initials: A
authors.lastname: Deheer-Graham
authors.affiliation: Public Health England, Microbiology Services Division, Salisbury, Wiltshire, United Kingdom.
authors.forename: J Mark
authors.initials: JM
authors.lastname: Sutton
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects; D002710:Chlorhexidine / Q000494:pharmacology; D004202:Disinfectants / Q000494:pharmacology*; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000472:pathogenicity; D008826:Microbial Sensitivity Tests; D009036:Moths / Q000382:microbiology*; D016254:Mutagenesis, Insertional; D010403:Penicillin Resistance / Q000187:drug effects; D014260:Triclosan / Q000494:pharmacology; D037521:Virulence Factors; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D004202:Disinfectants; D037521:Virulence Factors; D014260:Triclosan; D001618:beta-Lactamases; D002710:Chlorhexidine