The hospital environment constitutes a reservoir of opportunistic pathogens responsible for healthcare-associated infections (HCAI) such as
(
).
persistence within technological niches, the ...increasing emergence of epidemic high-risk clones in HCAI, the epidemiological link between plumbing strains and clinical strains, make it a major nosocomial pathogen. Therefore, understanding the mechanisms of
adaptation to hospital water systems would be useful in preventing HCAI. This review deciphers how copper resistance contributes to
adaptation and persistence in a hospital environment, especially within copper water systems, and ultimately to its success as a causative agent of HCAI. Numerous factors are involved in copper homeostasis in
, among which active efflux conferring copper tolerance, and copper-binding proteins regulating the copper compartmentalization between periplasm and cytoplasm. The functional harmony of copper homeostasis is regulated by several transcriptional regulators. The genomic island GI-7 appeared as especially responsible for the copper resistance in
. Mechanisms of copper and antibiotic cross-resistance and co-resistance are also identified, with potential co-regulation processes between them. Finally, copper resistance of
confers selective advantages in colonizing and persisting in hospital environments but also appears as an asset at the host/pathogen interface that helps in HCAI occurrence.
Human skin associated microbiota are increasingly described by culture-independent methods that showed an unexpected diversity with variation correlated with several pathologies. A role of microbiota ...disequilibrium in infection occurrence is hypothesized, particularly in surgical site infections. We study the diversities of operative site microbiota and its dynamics during surgical pathway of patients undergoing coronary-artery by-pass graft (CABG). Pre-, per-, and post-operative samples were collected from 25 patients: skin before the surgery, superficially and deeply during the intervention, and healing tissues. Bacterial diversity was assessed by DNA fingerprint using 16S rRNA gene PCR and Temporal Temperature Gel Electrophoresis (TTGE). The diversity of Operational Taxonomic Units (OTUs) at the surgical site was analyzed according to the stage of surgery. From all patients and samples, we identified 147 different OTUs belonging to the 6 phyla Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, Cyanobacteria, and Fusobacteria. High variations were observed among patients but common themes can be observed. The Firmicutes dominated quantitatively but were largely encompassed by the Proteobacteria regarding the OTUs diversity. The genera Propionibacterium and Staphylococcus predominated on the preoperative skin, whereas very diverse Proteobacteria appeared selected in peri-operative samples. The resilience in scar skin was partial with depletion in Actinobacteria and Firmicutes and increase of Gram-negative bacteria. Finally, the thoracic operative site presents an unexpected bacterial diversity, which is partially common to skin microbiota but presents particular dynamics. We described a complex bacterial community that gathers pathobionts and bacteria deemed to be environmental, opportunistic pathogens and non-pathogenic bacteria. These data stress to consider surgical microbiota as a "pathobiome" rather than a reservoir of individual potential pathogens.
The naturally acquired microbiota of
can influence vector's susceptibility to
and its capacity to transmit them. Microbiota modification is a new challenge to limit disease transmission but it still ...needs advanced knowledges on bacterial community in
, especially in wild and infected specimens from diverse origin and species. Bacterial culture and 16S rRNA gene-PCR associated to Temporal Temperature Gradient Electrophoresis (TTGE) were applied to explore the bacterial diversity in the abdomen of 100 wild specimens (eight
species) collected in the Binh Phuoc Province, Vietnam. Culture and PCR-TTGE were complementary. The bacterial richness of the mosquito collection encompassed 105 genera belonging to seven phyla, mostly
,
, and
.
,
, and
in
were the most prevalent genera. However,
represented by 57 genera was the most diversified phylum in
microbiota. The high overall of
-associated bacteria is confirmed with, to our knowledge, 51 genera described for the first time in
microbiota. However, the diversity per specimen was low with average diversity index and the average Shannon-Wiener score (H) of 4.843 and 5.569, respectively. The most represented bacterial genera were present in <30% of the specimens. Consequently, the core microbiota share by
from Binh Phuoc was very narrow, suggesting that
microbiota was greatly influenced by local environments. The repertory of bacterial genera in two specimens of
and
naturally infected by
was also described as preliminary results. Finally, this study completed the repertory of bacteria associated to wild
.
associated-bacteria appeared specimen-dependent rather than mosquitoe species- or group-dependent. Their origin and the existence of
-specific bacterial taxa are discussed.
Ochrobactrum intermedium is considered as an emerging human environmental opportunistic pathogen with mild virulence. The distribution of isolates and sequences described in literature and databases ...showed frequent association with human beings and polluted environments. As population structures are related to bacterial lifestyles, we investigated by multi-locus approach the genetic structure of a population of 65 isolates representative of the known natural distribution of O. intermedium. The population was further surveyed for genome dynamics using pulsed-field gel electrophoresis and genomics. The population displayed a clonal epidemic structure with events of recombination that occurred mainly in clonal complexes. Concerning biogeography, clones were shared by human and environments and were both cosmopolitan and local. The main cosmopolitan clone was genetically and genomically stable, and grouped isolates that all harbored an atypical insertion in the rrs. Ubiquitism and stability of this major clone suggested a clonal succes in a particular niche. Events of genomic reduction were detected in the population and the deleted genomic content was described for one isolate. O. intermedium displayed allopatric characters associated to a tendancy of genome reduction suggesting a specialization process. Considering its relatedness with Brucella, this specialization might be a commitment toward pathogenic life-style that could be driven by technological selective pressure related medical and industrial technologies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Placement of a central venous catheter (CVC) in the brachiocephalic vein (BCV) via the ultrasound (US)-guided supraclavicular approach was recently described in children. We aimed to determine the ...CVC maintenance-related complications at this site compared to the others (i.e., the femoral, the subclavian, and the jugular). We performed a retrospective data collection of prospectively registered data on CVC in young children hospitalized in a pediatric intensive care unit (PICU) during a 4-year period (May 2011 to May 2015). The primary outcome was a composite of central line-associated bloodstream infection (CLABSI) and deep-vein thrombosis (CLAT) according to the CVC site. Two hundred and twenty-five children, with respective age and weight of 7.1 (1.3–40.1) months and 7.7 (3.6–16) kg, required 257 CVCs, including 147 (57.2%) inserted in the BCV. The risk of the primary outcome was lower in the BCV than in the other sites (5.4 vs 16.4%; OR: 0.29; 95% CI: 0.12–0.70;
p
= 0.006). CLABSI incidence density rate (2.8 vs 8.96 per 1000 catheter days,
p
< 0.001) and CLAT incidence rate (2.7 vs 10%,
p
= 0.016) were also lower at this site.
Conclusion
: BCV catheterization via the US-guided supraclavicular approach may decrease CVC maintenance-related complications in children hospitalized in a PICU.
What is Known:
• Placement of a central venous catheter (CVC) in children is associated with mechanical risks during insertion, and with infectious and thrombotic complications during its maintenance.
• Ultrasound (US)-guided supraclavicular catheterization of the brachiocephalic vein (BCV) is feasible in infants and children.
What is New:
• This observational study suggested that BCV catheterization
via
the US-guided supraclavicular approach was associated with a lower risk of CVC insertion and maintenance-related complications, compared with the other catheterization sites.
In the context of the COVID-19 pandemic, wearing a face mask has become usual and ubiquitous, in both hospitals and community. However, the general public is consuming surgical or filtering facepiece ...(FFP) masks irrespective of their specificity, leading to a global supply shortage for the most exposed persons, who are healthcare workers. This underlines the urgent need to clarify the indications of the different categories of mask, in order to rationalize their use. This article specifies the French position for the rational use of respiratory protective equipment for healthcare workers.
Integrative and conjugative elements (ICEs) are widespread autonomous mobile DNA elements, containing the genes necessary for their excision, conjugative transfer, and insertion into a new host cell. ...ICEs can carry additional genes that are non-essential for their transfer but can confer adaptive phenotypes to the host. Our aim here was to better characterize the presence, distribution, and variation of ICEs related to the well-described ICEclc among Pseudomonas aeruginosa clinical isolates within a geographically restrained environment to understand the factors contributing to their evolution. We examined a total of 181 P. aeruginosa genome sequences obtained from patient or hospital environment isolates, most of which were obtained from a single hospital during 20 years of sampling. More than 90% of the isolates carried one or more ICEclc-like elements, with different degrees of conservation to the known ICEclc lifestyle and transfer genes. ICE clones closely matched their host clonal phylogeny, but not exclusively, indicating that both clonal evolution and ICE horizontal transfer are occurring in the hospital environment. ICEs from this singular hospital environment were mainly associated to three clone types found worldwide, suggesting an enrichment of local clones. Variable gene regions among the clinical P. aeruginosa ICEclc-type elements were notably enriched for heavy metal resistance genes, toxin-anti-toxin systems, potential efflux systems and multidrug resistance proteins, a metalloprotease and for a variety of regulatory systems, but not for specific recognizable antibiotic-resistance cassettes. Clonal persistence suggests adaptive benefits of these functional categories, and micro-patterns of gene gain and loss indicate ongoing ICE evolution within the P. aeruginosa hosts.IMPORTANCEMicrobial populations swiftly adapt to changing environments through horizontal gene transfer. While the mechanisms of gene transfer are well known, the impact of environmental conditions on the selection of transferred gene functions remains less clear. We investigated ICEs, specifically the ICEclc-type, in Pseudomonas aeruginosa clinical isolates. Our findings revealed co-evolution between ICEs and their hosts, with ICE transfers occurring within strains. Gene functions carried by ICEs are positively selected, including potential virulence factors and heavy metal resistance. Comparison to publicly available P. aeruginosa genomes unveiled widespread antibiotic-resistance determinants within ICEclc clades. Thus, the ubiquitous ICEclc family significantly contributes to P. aeruginosa’s adaptation and fitness in diverse environments.
To assess the residual risk of waterborne contamination by Pseudomonas aeruginosa from a water network colonized by a single genotype sequence type (ST) 299 despite the presence of antimicrobial ...filters in a medical intensive care unit (ICU).
During the first 19-month period since the ICU opened, contamination of the water network was assessed monthly by collecting water upstream of the filters. Downstream water was also sampled to assess the efficiency of the filters. P. aeruginosa isolates from patients were collected and compared with the waterborne ST299 P. aeruginosa by multiplex-rep polymerase chain reaction (PCR), pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing. Cross-transmission events by other genotypes of P. aeruginosa were also assessed.
Overall, 1.3% of 449 samples of filtered water were positive for P. aeruginosa in inoculum, varying between 1 and 104 colony-forming units/100 mL according to the tap. All P. aeruginosa hydric isolates belonged to ST299 and displayed fewer than two single nucleotide polymorphisms (SNPs). Among 278 clinical isolates from 122 patients, 10 isolates in five patients showed identical profiles to the hydric ST299 clone on both multiplex-rep PCR and PFGE, and differed by an average of fewer than five SNPs, confirming the water network reservoir as the source of contamination by P. aeruginosa for 4.09% of patients. Cross-transmission events by other genotypes of P. aeruginosa were responsible for the contamination of 1.75% of patients.
Antimicrobial filters are not sufficient to protect patients from waterborne pathogens when the water network is highly contaminated. A microbiological survey of filtered water may be needed in units hosting patients at risk of P. aeruginosa infections, even when all water points-of-use are fitted with filters.
•Pseudomonas aeruginosa urinary tract infections occurred after cystoscopies.•The investigation identified a damaged cystoscope contaminated by P. aeruginosa acting as a relay object.•This outbreak ...urges us not to trivialize urinary tract infections occurring after cystoscopy.•Patients should be advised to signal the occurrence of urologic symptoms after urologic exploration.
The investigation of an outbreak of Pseudomonas aeruginosa urinary tract infections after ambulatory cystoscopies identified a damaged cystoscope contaminated by P aeruginosa and acting as a relay object. This outbreak urges us not to trivialize urinary tract infections occurring after an elective cystoscopy. Patients should be advised to signal the occurrence of urologic symptoms after urologic exploration.
In the context of a 3-month extended-spectrum beta-lactamase-producing
Klebsiella pneumonia
(ESBL-KP) outbreak in a neonatal care center (NCC), hygiene practices and hospital environment were ...investigated. ESBL-KP strains isolated from patients and environment were compared by molecular typing. The density of incidence of multi-drug-resistant bacteria (MDRB) was calculated from January 2014 to September 2016. The 3-month ESBL-KP outbreak involved 19 patients. Clinical strains from the 19 patients displayed the same molecular profile between them, and with a strain isolated from an incubator after cleaning. Furthermore, 52.4% of incubator mattresses were positive for diverse pathogens. Hygiene practices were acceptable except for external practitioners and parents. In addition to classical infection control (IC) measures, the replacement of mattresses and the improvement of incubators disinfection stopped the outbreak. The protocol of disinfection was revised and microbiological control was implemented. A significant decrease of MDRB incidence was concomitant (
p
value = 0.03219) but 3 months later, MDRB incidence increased again.
Conclusion
: This investigation highlighted incubators and mattresses as critical materials associated to infectious risk in NCC. NCC and IC teams should implement efficient protocol for incubators disinfection and monitoring.
What is Known:
•
Environment in neonatal intensive care units is often suspected as reservoir for Enterobacteriaceae outbreaks but is scarcely investigated
.
•
Incubators and mattresses offer wet and warm conditions suitable for pathogens multiplication
,
but microbiological survey is not performed routinely for assessing bacterial contamination
.
What is New:
•
Incubators and mattresses serve as reservoir for pathogens and relay in outbreak
.
•
An infection control protocol associating efficient disinfection and microbiology analysis is proposed
.
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