Search PubMed⌕ Search

PubMed · 10817647

'Infectious web'.

Abstract

The current web summary highlights internet sites describing the growing problem of Staphylococcus aureus antibiotic resistance, the epidemiology and prevention of malaria, biochemical and genetic aspects of lipopolysaccharide action, and the history and treatment of hepatitis C infections.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2000. 'Infectious web'.. https://pubmed.ncbi.nlm.nih.gov/10817647/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Dual-species interactions with intestinal bacteria drive multi-drug resistance in Campylobacter.

OBJECTIVES: Multidrug-resistant (MDR) Campylobacter infections are an increasing clinical concern, as rising fluoroquinolone (FQ) resistance leaves macrolides as the primary treatment option. We investigated multidrug resistance in clinical Campylobacter samples from Germany. METHODS: We analyzed 6980 clinical isolates (2010-2022), performing phenotypic susceptibility testing and sequencing on 2912 genomes. Cultures showing multidrug resistance were studied using scanning electron microscopy (SEM). RESULTS: We found that 453 (6%) Campylobacter samples were resistant to both FQ and macrolides. Two of the C. jejuni samples were resistant to antibiotics from ten different classes. Genome analysis revealed that these samples, despite being derived from single colonies, contained >10% Enterococcus DNA reads. SEM confirmed the presence of coccoid bacteria interspersed with spiral-shaped Campylobacter. Additional culture-based purification resulted in pure C. jejuni isolates that retained FQR but lost macrolide resistance. The presence of MDR Enterococcus spp. in the mixed samples protected C. jejuni from above-MIC (minimum inhibitory concentration) concentrations of several ribosome-targeting antimicrobials whereas pure Campylobacter were susceptible. CONCLUSIONS: The impact of microbial interactions on resistance phenotypes is poorly understood. We show that close interactions with highly resistant intestinal bacteria can induce multidrug resistance phenotypes in Campylobacter. These findings highlight that microbial context shapes antibiotic resistance and may influence treatment outcomes.

Campylobacter jejuni↗

Identification and molecular characterisation of CmeB, a Campylobacter jejuni multidrug efflux pump.

A multidrug efflux pump gene (cmeB) was identified from the published Campylobacter jejuni genome sequence. Secondary structural analysis showed that the gene encoded a protein belonging to the resistance nodulation cell division (RND) family of efflux transporters. The gene was inactivated by insertional mutagenesis. Compared with the wild-type strain (NCTC 11168), the resultant knockout strain (NCTC 11168-cmeB::kan(r)) displayed increased susceptibility to a range of antibiotics including beta-lactams, fluoroquinolones, macrolides, chloramphenicol, tetracycline, ethidium bromide, the dye acridine orange and the detergent sodium dodecyl sulfate. Accumulation of ciprofloxacin was increased in the knockout mutant, but carbonyl cyanide m-chlorophenyl hydrazone, a proton motive force inhibitor, had less effect upon ciprofloxacin accumulation in the knockout mutant compared with NCTC 11168. These data show that the identified gene encodes an RND-type multi-substrate efflux transporter, which contributes to intrinsic resistance to a range of structurally unrelated compounds in C. jejuni. This efflux pump has been named CmeB (for Campylobacter multidrug efflux).

Campylobacter jejuni↗

Campylobacter DNA is present in circulating myelomonocytic cells of healthy persons and in persons with Guillain-Barré syndrome.

Campylobacter jejuni is the prime cause of foodborne bacterial gastroenteritis. An important complication of C. jejuni enteritis is Guillain-Barré syndrome (GBS), an immune-mediated disorder of the peripheral nerve. The presence of C. jejuni DNA in peripheral blood mononuclear cells (PBMC) of patients with GBS, patients with C. jejuni enteritis, and healthy subjects was studied. Two target genes, the flagellin and the ceuE genes, were used for polymerase chain reaction (PCR) identification of Campylobacter species in DNA extracted from PBMC. Approximately 30% of the healthy subjects and 50% of the patients with GBS had PBMC containing C. jejuni DNA as verified by Southern blot analysis or sequencing of the PCR products. Cell sorting revealed that Campylobacter DNA was present in CD14(+) and CD33(+) populations, indicating that cells from the myelomonocytic lineage are the Campylobacter DNA-carrying cells. These findings show that Campylobacter DNA is present in blood cells of healthy humans, although viable bacteria could not be demonstrated.

Campylobacter jejuni↗