Background: Pseudomonas aeruginosa outer membrane protein OprH has been hypothesized to confer antibiotic resistance by interaction with LPS. Results: The structure of OprH was solved and LPS interaction was demonstrated by solution NMR supported by pulldown and biochemical assays. Conclusion: OprH forms a ␤-barrel in membrane and interacts with LPS in vivo and in vitro. Significance: Structure and lipid interactions may help understand antibiotic resistance.

Salmonella Typhimurium isolate D23580 represents a recently identified ST313 lineage of invasive non-typhoidal Salmonellae (iNTS). One of the differences between this lineage and other non-iNTS S. Typhimurium isolates is the presence of prophage BTP1. This prophage encodes a gtrC gene, implicated in O-antigen modification. GtrCBTP1 is essential for maintaining O-antigen length in isolate D23580, since a gtrBTP1 mutant yields a short O-antigen. This phenotype can be complemented by gtrCBTP1 or very closely related gtrC genes. The short O-antigen of the gtrBTP1 mutant was also compensated by deletion of the BTP1 phage tailspike gene in the D23580 chromosome. This tailspike protein has a putative endorhamnosidase domain and thus may mediate O-antigen cleavage. Expression of the gtrCBTP1 gene is, in contrast to expression of many other gtr operons, not subject to phase variation and transcriptional analysis suggests that gtrC is produced under a variety of conditions. Additionally, GtrCBTP1 expression is necessary and sufficient to provide protection against BTP1 phage infection of an otherwise susceptible strain. These data are consistent with a model in which GtrCBTP1 mediates modification of the BTP1 phage O-antigen receptor in lysogenic D23580, and thereby prevents superinfection by itself and other phage that uses the same O-antigen co-receptor.

BackgroundCryptosporidium infection causes gastrointestinal disease and has a worldwide distribution. The highest burden is in developing countries.ObjectivesWe sought to conduct a systematic review and meta-analysis to identify Cryptosporidium risk factors in Low and Middle Income countries (LMICs).MethodsMedline Ovid and Scopus databases were searched with no restriction on year or language of publication. All references were screened independently in duplicate and were included if they presented data on at least 3 risk factors. Meta-analyses using random effects models were used to calculate overall estimates for each exposure.ResultsThe most frequently reported risk factors in the 15 included studies were overcrowding, household diarrhoea, poor quality drinking water, animal contact, open defecation/ lack of toilet and breastfeeding. The combined odds ratio for animal contact was 1.98 (95%CI: 1.11–3.54) based on 11 studies and for diarrhoea in the household 1.98 (95%CI: 1.13–3.49) based on 4 studies. Open defecation was associated with a pooled odds ratio of 1.82 (95%CI: 1.19–2.8) based on 5 studies. Poor drinking water quality was not associated with a significant Cryptosporidium risk, odds ratio 1.06 (95%CI: 0.77–1.47). Breastfeeding was protective with pooled odds ratio 0.4 (95%CI: 0.13–1.22), which was not statistically significant.ConclusionsBased on the included studies, crowded living conditions, animal contact and open defecation are responsible for the majority of Cryptosporidium cases in LMICs. Future studies investigating Cryptosporidium risk factors should have a good study design and duration, include appropriate number of cases, select suitable controls, investigate multiple relevant risk factors, fully report data and perform multivariate analysis.

Out of potential sources for STEC exposure, undercooked meat and contact with animals and their environment were the most frequently found transmission routes. Decreasing the chances of acquiring the bacteria by these methods would additionally cut down on the other major transmission route, person-to-person spread.