Mannose binding lectin plays a crucial role in innate immunity against yeast by enhanced complement activation and enhanced uptake of polymorphonuclear cells

<p>Abstract</p> <p>Background</p> <p>Mannose binding lectin (MBL) is an important host defence protein against opportunistic fungal pathogens. This carbohydrate-binding protein, an opsonin and lectin pathway activator, binds through multiple lectin domains to the repeating sugar arrays displayed on the surface of a wide range of clinically relevant microbial species. We investigated the contribution of MBL to antifungal innate immunity towards <it>C. parapsilosis in vitro</it>.</p> <p>Results</p> <p>High avidity binding was observed between MBL and <it>C. albicans </it>and <it>C. parapsilosis</it>. Addition of MBL to MBL deficient serum increased the deposition of C4 and C3b and enhanced the uptake of <it>C. albicans</it>, <it>C. parapsilosis </it>and acapsular <it>C. neoformans </it>by polymorphonuclear cells (PMNs). Compared to other microorganisms, such as <it>Escherichia coli</it>, <it>Staphylococcus aureus </it>and <it>Cryptococcus neoformans</it>, <it>C. parapsilosis </it>and <it>Candida albicans </it>were potent activators of the lectin pathway.</p> <p>Conclusion</p> <p>Our results suggest that MBL plays a crucial role in the innate immunity against infections caused by yeast by increasing uptake by PMN.</p

Dissemination of Cephalosporin Resistance Genes between Escherichia coli Strains from Farm Animals and Humans by Specific Plasmid Lineages

Third-generation cephalosporins are a class of β-lactam antibiotics that are often used for the treatment of human infections caused by Gram-negative bacteria, especially Escherichia coli. Worryingly, the incidence of human infections caused by third-generation cephalosporin-resistant E. coli is increasing worldwide. Recent studies have suggested that these E. coli strains, and their antibiotic resistance genes, can spread from food-producing animals, via the food-chain, to humans. However, these studies used traditional typing methods, which may not have provided sufficient resolution to reliably assess the relatedness of these strains. We therefore used whole-genome sequencing (WGS) to study the relatedness of cephalosporin-resistant E. coli from humans, chicken meat, poultry and pigs. One strain collection included pairs of human and poultry-associated strains that had previously been considered to be identical based on Multi-Locus Sequence Typing, plasmid typing and antibiotic resistance gene sequencing. The second collection included isolates from farmers and their pigs. WGS analysis revealed considerable heterogeneity between human and poultry-associated isolates. The most closely related pairs of strains from both sources carried 1263 Single-Nucleotide Polymorphisms (SNPs) per Mbp core genome. In contrast, epidemiologically linked strains from humans and pigs differed by only 1.8 SNPs per Mbp core genome. WGS-based plasmid reconstructions revealed three distinct plasmid lineages (IncI1- and IncK-type) that carried cephalosporin resistance genes of the Extended-Spectrum Beta-Lactamase (ESBL)- and AmpC-types. The plasmid backbones within each lineage were virtually identical and were shared by genetically unrelated human and animal isolates. Plasmid reconstructions from short-read sequencing data were validated by long-read DNA sequencing for two strains. Our findings failed to demonstrate evidence for recent clonal transmission of cephalosporin-resistant E. coli strains from poultry to humans, as has been suggested based on traditional, low-resolution typing methods. Instead, our data suggest that cephalosporin resistance genes are mainly disseminated in animals and humans via distinct plasmids

Dynamics of intestinal carriage of Extended-spectrum Beta-lactamase producing Enterobacteriaceae in the Dutch general population (2014-2016).

BACKGROUND: In the Netherlands, the prevalence of intestinal extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) carriage in community-dwelling subjects is ~5%. Little is known about the dynamics of ESBL-E carriage. METHODS: In a nationwide, population-based study (2014-2016) with 4177 community-dwelling subjects, fecal samples from 656 subjects were collected after 1 (time point [T] = 1) and 6 (T = 2) months. The growth of ESBL-E was quantified and a whole-genome sequence analysis was performed. Subjects were categorized as either an incidental, short-term, or long-term carrier or as a noncarrier. Risk factors were determined by random forest models and logistic regression. The transmissibility and duration of ESBL-E carriage was quantified using a transmission model, which also incorporated previous study data. RESULTS: Out of 656 participants, 96 were ESBL-E carriers at T = 0. Of these, 66 (10.1%) subjects were incidental carriers, 22 (3.3%) were short-term carriers, and 38 (5.8%) were long-term carriers; the remaining 530 (80.8%) were noncarriers. The risk factors for long-term carriage were travelling to Asia, swimming in a sea/ocean, and not changing the kitchen towel daily. The log-transformed colony forming units ratio at T = 0 was predictive for ESBL-E carriage at T = 1 (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.2-1.6) and T = 2 (OR, 1.2; 95% CI, 1.1-1.4). Model simulations revealed a median decolonization rate of 2.83/year, an average duration of carriage of 0.35 years, and an acquisition rate of 0.34/year. The trend of the acquisition rate during the study period was close to 0. CONCLUSIONS: The risk factors for long-term ESBL-E carriage were travel- and hygiene-related. The dynamics of ESBL-E carriage in the general Dutch population are characterized by balancing decolonization and acquisition rates

Taxonomic position, antibiotic resistance and virulence factor production by Stenotrophomonas isolates from patients with cystic fibrosis and other chronic respiratory infections

BACKGROUND: The potential pathogenic role of Stenotrophomonas maltophilia in lung disease and in particular in cystic fibrosis is unclear. To develop further understanding of the biology of this taxa, the taxonomic position, antibiotic resistance and virulence factors of S. maltophilia isolates from patients with chronic lung disease were studied. RESULTS: A total of 111 isolates recovered between 2003 and 2016 from respiratory samples from patients in five different countries were included. Based on a cut-off of 95%, analysis of average nucleotide identity by BLAST (ANIb) showed that the 111 isolates identified as S. maltophilia by Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/MS) belonged to S. maltophilia (n = 65), S. pavanii (n = 6) and 13 putative novel species (n = 40), which each included 1–5 isolates; these groupings coincided with the results of the 16S rDNA analysis, and the L1 and L2 ß-lactamase Neighbor-Joining phylogeny. Chromosomally encoded aminoglycoside resistance was identified in all S. maltophilia and S. pavani isolates, while acquired antibiotic resistance genes were present in only a few isolates. Nevertheless, phenotypic resistance levels against commonly used antibiotics, determined by standard broth microbroth dilution, were high. Although putative virulence genes were present in all isolates, the percentage of positive isolates varied. The Xps II secretion system responsible for the secretion of the StmPr1–3 proteases was mainly limited to isolates identified as S. maltophilia based on ANIb, but no correlation with phenotypic expression of protease activity was found. The RPF two-component quorum sensing system involved in virulence and antibiotic resistance expression has two main variants with one variant lacking 190 amino acids in the sensing region. CONCLUSIONS: The putative novel Stenotrophomonas species recovered from patient samples and identified by MALDI-TOF/MS as S. maltophilia, differed from S. maltophilia in resistance and virulence genes, and therefore possibly in pathogenicity. Revision of the Stenotrophomonas taxonomy is needed in order to reliably identify strains within the genus and elucidate the role of the different species in disease. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12866-022-02466-5

Population distribution of Beta-lactamase conferring resistance to third-generation cephalosporins in human clinical Enterobacteriaceae in the Netherlands.

There is a global increase in infections caused by Enterobacteriaceae with plasmid-borne β-lactamases that confer resistance to third-generation cephalosporins. The epidemiology of these bacteria is not well understood, and was, therefore, investigated in a selection of 636 clinical Enterobacteriaceae with a minimal inhibitory concentration >1 mg/L for ceftazidime/ceftriaxone from a national survey (75% E. coli, 11% E. cloacae, 11% K. pneumoniae, 2% K. oxytoca, 2% P. mirabilis). Isolates were investigated for extended-spectrum β-lactamases (ESBLs) and ampC genes using microarray, PCR, gene sequencing and molecular straintyping (Diversilab and multi-locus sequence typing (MLST)). ESBL genes were demonstrated in 512 isolates (81%); of which 446 (87%) belonged to the CTX-M family. Among 314 randomly selected and sequenced isolates, bla(CTX-M-15) was most prevalent (n = 124, 39%), followed by bla(CTX-M-1) (n = 47, 15%), bla(CTX-M-14) (n = 15, 5%), bla(SHV-12) (n = 24, 8%) and bla(TEM-52) (n = 13, 4%). Among 181 isolates with MIC ≥16 mg/L for cefoxitin plasmid encoded AmpCs were detected in 32 and 27 were of the CMY-2 group. Among 102 E. coli isolates with MIC ≥16 mg/L for cefoxitin ampC promoter mutations were identified in 29 (28%). Based on Diversilab genotyping of 608 isolates (similarity cut-off >98%) discriminatory indices of bacteria with ESBL and/or ampC genes were 0.994, 0.985 and 0.994 for E. coli, K. pneumoniae and E. cloacae, respectively. Based on similarity cut-off >95% two large clusters of E. coli were apparent (of 43 and 30 isolates) and 21 of 21 that were typed by belonged to ST131 of which 13 contained bla(CTX-M-15). Our findings demonstrate that bla(CTX-M-15) is the most prevalent ESBL and we report a larger than previously reported prevalence of ampC genes among Enterobacteriaceae responsible for resistance to third-generation cephalosporins

Sequence-Based Epidemiology of an OXA-48 Plasmid during Hospital Outbreak

A large OXA-48 outbreak in The Netherlands involved the spread of OXA-48-producing Enterobacteriaceae among at least 118 patients, suggesting horizontal transfer of this resistance gene through one or more plasmids. Elucidating transmission dynamics of resistance plasmids is hampered by the low resolution of classic typing methods. This study aimed to investigate the molecular epidemiology of plasmids carrying the OXA-48 carbapenemase using a next-generation sequencing approach. A total of 68 OXA-48-producing Enterobacteriaceae isolates collected from the hospital outbreak, as well as 22 non-outbreak-related OXA-48-producing Enterobacteriaceae isolates from The Netherlands, Libya, and Turkey were selected. Plasmids were sequenced using the Illumina MiSeq platform, and read sets were assembled and analyzed. In all plasmids, bla OXA-48 was embedded in transposon Tn1999.2 and located on a ca. 62-kb IncL/M conjugative plasmid in 14 different species. There were a maximum of 2 single nucleotide polymorphisms (SNPs) between the core sequence alignment of all plasmids. Closely related sequence variants of this plasmid were detected in nonoutbreak isolates from The Netherlands and other countries. Thirty-one of 89 OXA-48producing isolates also harbored bla CTX-M-15, which was not located on the bla OXA-48carrying plasmid. Sequencing of four plasmids harboring bla CTX-M-15 revealed extensive plasmid heterogeneity. A ca. 62-kb plasmid was responsible for the OXA-48 outbreak in a Dutch hospital. Our findings provide strong evidence for both within-host interspecies and between-host dissemination of plasmid-based OXA-48 during a nosocomial outbreak. These findings exemplify the complex epidemiology of carbapenemase-producing Enterobacteriaceae (CPE)

Prevalence, risk factors and genetic characterisation of extended-spectrum beta-lactamase and carbapenemase-producing Enterobacteriaceae (ESBL-E and CPE) : a community-based cross-sectional study, the Netherlands, 2014 to 2016

Background The epidemiology of carriage of extended-spectrum beta-lactamase-producing (ESBL-E) and carbapenemase-producing Enterobacteriaceae (CPE) in the general population is unknown.AimIn this observational study, the prevalence and risk factors for intestinal ESBL-E and CPE carriage in the Dutch general population were determined. ESBL-E were characterised.  Methods From 2014 to 2016, ca 2,000 residents were invited monthly to complete a questionnaire and provide a faecal sample, which was tested for ESBL-E. The first 1,758 samples were also tested for CPE. Risk factors for ESBL-E carriage were identified by multivariable logistic regression analysis. ESBL-E isolates underwent whole genome sequencing.  Results Of 47,957 individuals invited, 4,177 (8.7%) completed the questionnaire and provided a faecal sample. ESBL-E were detected in 186 (4.5%) individuals, resulting in an adjusted prevalence of 5.0% (95% confidence interval (CI):3.4-6.6%). Risk factors were: born outside the Netherlands (odds ratio (OR): 1.99; 95% CI: 1.16-4.54), eating in restaurants > 20 times/year (OR: 1.70; 95% CI: 1.04-2.76), antibiotic use < 6 months ago (OR: 2.05; 95% CI: 1.05-4.03), swimming in sea/ocean < 12 months ago (OR: 1.63; 95% CI: 1.11-2.39), travelling to Africa (OR: 3.03; 95% CI: 1.23-7.46) or Asia (OR: 2.00; 95% CI: 1.02-3.90) < 12 months ago, and not changing kitchen towels daily (OR: 2.19; 95% CI: 1.24-3.87). The last had the largest population attributable risk (PAR) (47.5%). Eighty-four of 189 (44.4%) ESBL-E isolates carried blaCTX-M-15. Escherichia coli isolates belonged to 70 different sequence types (ST)s, of which ST131 (42/178 isolates; 23.6%) was most prevalent. Associations were observed between IncFIA plasmids and ST131 and blaCTX-M-27, and between IncI1 and ST88 and blaCTX-M-1. No CPE were detected.  Conclusions The prevalence of ESBL-E carriage in the Netherlands' community-dwelling population is 5.0%. Identified risk factors were mostly travelling (particularly to Asia and Africa) and kitchen hygiene. CPE were not detected

Dynamics of Intestinal Carriage of Extended-Spectrum Beta-lactamase–Producing Enterobacteriaceae in the Dutch General Population, 2014–2016

BACKGROUND: In the Netherlands, the prevalence of intestinal extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) carriage in community-dwelling subjects is ~5%. Little is known about the dynamics of ESBL-E carriage. METHODS: In a nationwide, population-based study (2014-2016) with 4177 community-dwelling subjects, fecal samples from 656 subjects were collected after 1 (time point [T] = 1) and 6 (T = 2) months. The growth of ESBL-E was quantified and a whole-genome sequence analysis was performed. Subjects were categorized as either an incidental, short-term, or long-term carrier or as a noncarrier. Risk factors were determined by random forest models and logistic regression. The transmissibility and duration of ESBL-E carriage was quantified using a transmission model, which also incorporated previous study data. RESULTS: Out of 656 participants, 96 were ESBL-E carriers at T = 0. Of these, 66 (10.1%) subjects were incidental carriers, 22 (3.3%) were short-term carriers, and 38 (5.8%) were long-term carriers; the remaining 530 (80.8%) were noncarriers. The risk factors for long-term carriage were travelling to Asia, swimming in a sea/ocean, and not changing the kitchen towel daily. The log-transformed colony forming units ratio at T = 0 was predictive for ESBL-E carriage at T = 1 (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.2-1.6) and T = 2 (OR, 1.2; 95% CI, 1.1-1.4). Model simulations revealed a median decolonization rate of 2.83/year, an average duration of carriage of 0.35 years, and an acquisition rate of 0.34/year. The trend of the acquisition rate during the study period was close to 0. CONCLUSIONS: The risk factors for long-term ESBL-E carriage were travel- and hygiene-related. The dynamics of ESBL-E carriage in the general Dutch population are characterized by balancing decolonization and acquisition rates