To identify the mechanism(s) underlying cefotaxime resistance in 118 of 21 641 (0.55%) non-typhoidal Salmonella enterica isolates collected from humans throughout England and Wales from January 2010 to September 2012. Non-duplicate isolates (n = 118) resistant to cefotaxime (MICs >1 mg/L) were screened by PCR for genes encoding CTX-M extended-spectrum β-lactamases (ESBLs) and associated ISEcp1-like elements, and for genes encoding acquired AmpC, SHV, TEM, VEB, PER and GES β-lactamases. Sequencing was used to identify specific alleles in selected isolates. Carbapenem resistance was sought by ertapenem disc screening. Seventy-nine isolates (0.37% of all referred S. enterica) produced ESBLs, 37 isolates (0.17%) produced CMY-type AmpC enzymes, and 1 isolate had both enzyme types; the mechanism of cefotaxime resistance in 3 isolates could not be identified. Group 1 CTX-M genes were identified in 57 isolates belonging to 22 serotypes, with CTX-M-1 (n = 11), -15 (n = 9) and -55/57 (n = 8) the most prevalent alleles among the 29 (51%) investigated. CTX-M-2 (n = 5), -14 (n = 5), -8 (n = 1) and -65 (n = 1) were also identified. TEM-52 was identified in two isolates and SHV-12 in seven isolates. There was no evidence of carbapenem resistance. ESBL and AmpC genes were detected in both domestically acquired and travel-associated salmonellae. Eighty-nine isolates (75%) were multidrug resistant (resistant to at least three antimicrobial classes) and 42 (36%) had decreased susceptibility to ciprofloxacin (MICs 0.25–1 mg/L), with a further 13 (11%) isolates resistant (MICs >1 mg/L). The prevalence of CTX-M and acquired AmpC genes in human non-typhoidal S. enterica from England and Wales is still low, but has increased from 0.03% in 2001–03 to 0.49% in 2010–12. Resistance to third-generation cephalosporins requires monitoring as it may reduce therapeutic options.

Cryptosporidiosis is one of the leading causes of diarrhoeal illness and mortality induced by protozoan pathogens worldwide. As a largely waterborne disease, emphasis has been given to the study of Cryptosporidium spp. in surface waters, readily susceptible to pathogenic contamination. Conversely, the status of Cryptosporidium in potable groundwater sources, generally regarded as a pristine and "safe" drinking-water supply owing to (sub)-soil protection, remains largely unknown. As such, this investigation presents the first literature review aimed to ascertain the global prevalence of Cryptosporidium in groundwater supply sources intended for human consumption. Thirty-seven peer-reviewed studies were identified and included in the review. Groundwater sample and supply detection rates (estimated 10-20%) indicate Cryptosporidium is frequently present in domestic groundwater sources, representing a latent health concern for groundwater consumers. Specifically, sample (10.4%) and source (19.1%) detection rates deriving from comprehensive "temporal" investigations are put forward as representative of a contamination 'baseline' for Cryptosporidium in 'domestic' groundwater supplies. Proposed 'baseline' prevalence figures are largely applicable in preventive risk-based catchment and groundwater quality management including the formulation of Quantitative Microbial Risk Assessment (QMRA). Notwithstanding, a large geographical disparity in available investigations and lack of standardized reporting restrict the transferability of research findings. Overall, the mechanisms responsible for Cryptosporidium transport and ingress into groundwater supplies remain ambiguous, representing a critical knowledge gap, and denoting a distinctive lack of integration between groundwater and public-health sub-disciplines among investigations. Key recommendations and guidelines are provided for prospective studies directed at more integrative and multi-disciplinary research.

The first hybrid molecule of a β-lactam antibiotic and a host defence peptide and a method for the preparation of this type of molecule are reported. Conjugation of an antimicrobial peptide to a cephalosporin, through a cleavable linker, reversibly masks one of the activity determinants of the peptide. Its release from the β-lactam core can be selectively triggered by bacterial enzymes (β-lactamases) which mediate resistance to β-lactam agents. A prototypical cephalothin-bactenecin candidate was synthesised, using a copper(I)-catalysed azide–alkyne cyclo-addition reaction for the conjugation step. Enzymatic hydrolysis assays of this candidate were initially performed with a purified β-lactamase to confirm that the peptide can be released from the cephalosporin. The antimicrobial activity of the conjugate was then assessed against representative strains of bacteria and compared to the activities of its parent β-lactam and peptide components and to those of two analogous conjugates based on non-cleavable linkers. The results of these assays indicate that the conjugate has an activity distinct from its separate constituents and that the release of the peptide from the cephalosporin may contribute to its mechanism of action. Furthermore, the results of antimicrobial assays performed with an isogenic strain of bacteria expressing or not an extended-spectrum β-lactamase, suggest that antimicrobial peptide prodrug candidates targeting resistant bacteria could be generated from these hybrid antibiotics.

Hypervirulent Klebsiella pneumoniae (hvKp) has emerged as a pathogen of global concern associated with invasive community-acquired infections. The combination of hypervirulence and carbapenem resistance can result in severe and difficult-to-treat infections. This retrospective study aimed to investigate the spread of hvKp sequence type 23 (ST23) in Ireland and the convergence of hypervirulent (hv) and antimicrobial resistance genotypes. Short-read sequences (PE300) for 90 K. pneumoniae ST23 isolates were generated by the Galway Reference Laboratory Services (GRLS). Isolates were from screening swabs (n=59), invasive infections (n=18), non-invasive sites (n=12) and the hospital environment (n=1). The virulence and resistance content were assessed genomically using Kleborate (v2.2.0), ABRicate (v1.0.1) and Platon (v1.6). The in vivo virulence of the isolates was assessed using a murine model. All isolates were genotypically hv with 88/90 isolates having a maximal Kleborate virulence score of 5 including carriage of key genes. Eighty-two per cent of isolates (74/90) carried a carbapenemase gene (bla _OXA-48/bla _OXA-181/bla _NDM-1), and 42% carried resistance genes to 3 or more antimicrobial classes. Core genomic delineation revealed the isolates to be clonal with similar resistance and virulence profiles. Two distinct clusters of Irish isolates were detected consisting of 82/90 of the isolates. Isolates associated with carriage and infection demonstrated similar in vivo virulence. An established clone of hvKp ST23 is circulating within Ireland and causing both colonization and infection of patients. The lack of reliable screening methods for hvKp makes its detection and control in the healthcare setting challenging.

Environmental water is considered one of the main vehicles for the transmission of antimicrobial resistance (AMR), posing an increasing threat to humans and animals health. Continuous efforts are being made to eliminate AMR; however, the detection of AMR pathogens from water samples often requires at least one culture step, which is time‐consuming and can limit sensitivity. In this study, we employed comparative genomics to identify the prevalence of AMR genes within among: Escherichia coli , Klebsiella , Salmonella enterica and Acinetobacter , using publicly available genomes. The mcr‐1 , blaKPC (KPC‐1 to KPC‐4 alleles), blaOXA‐48 , blaOXA‐23 and blaVIM (VIM‐1 and VIM‐2 alleles) genes are of great medical and veterinary significance, thus were selected as targets for the development of isothermal loop‐mediated amplification (LAMP) detection assays. We also developed a rapid and sensitive sample preparation method for an integrated culture‐independent LAMP‐based detection from water samples. The developed assays successfully detected the five AMR gene markers from pond water within 1 h and were 100% sensitive and specific with a detection limit of 0.0625 μg/mL and 10 cfu/mL for genomic DNA and spiked bacterial cells, respectively. The integrated detection can be easily implemented in resource‐limited areas to enhance One Health AMR surveillances and improve diagnostics.