Microbiological colonization of peripheral venous catheters: a prospective observational study in a Swedish county hospital.

BACKGROUND: Most peripheral venous catheters (PVCs) used in Scandinavia are fitted with an injection port, creating an open PVC system. This port is difficult to disinfect, which may lead to the introduction of micro-organisms upon use. AIM: To investigate the prevalence of microbiological colonization of the injection port and internal lumen of ported PVCs with a minimum dwell time of 48 h at sample collection. METHODS: Adult patients admitted to different medical and surgical departments and the intensive care unit were invited to participate in this prospective observational study. With the PVC in situ, the injection port and internal lumen were swabbed and cultured separately. Demographic and clinical data were collected to compare patients with colonized and non-colonized PVCs. FINDINGS: In total, 300 PVCs from 300 patients were analysed. Of these, 33 patients (11.0%) had at least one positive culture. The colonization locations were as follows: port only, 26 (8.7%); internal lumen only, 5 (1.7%); and port and internal lumen, 2 (0.7%). The colonization rate was significantly higher in the injection port than in the internal lumen (P<0.0001). A ported PVC inserted in the hand incurred a significant risk of colonization (P=0.03). The odds ratio for colonization among patients in the infectious diseases department was 0.1 (95% confidence interval 0.1-1; P<0.06) compared with patients in the medical department. CONCLUSION: This study showed that 11% of ported PVCs were colonized by micro-organisms, with the vast majority (8.7%) of colonization occurring in the injection port. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; ID NCT03351725.

Genetic makeup of Shiga toxin-producing Escherichia coli in relation to clinical symptoms and duration of shedding: a microarray analysis of isolates from Swedish children.

Shiga toxin (Stx)-producing Escherichia coli (STECs) cause non-bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome, and are the primary cause of acute renal failure in children worldwide. This study investigated the correlation of genetic makeup of STEC strains as revealed by DNA microarray to clinical symptoms and the duration of STEC shedding. All STEC isolated (n = 96) from patients <10 years of age in Jönköping County, Sweden from 2003 to 2015 were included. Isolates were characterized by DNA microarray, including almost 280 genes. Clinical data were collected through a questionnaire and by reviewing medical records. Of the 96 virulence genes (including stx) in the microarray, 62 genes were present in at least one isolate. Statistically significant differences in prevalence were observed for 21 genes when comparing patients with bloody diarrhea (BD) and with non-bloody stool (18 of 21 associated with BD). Most genes encode toxins (e.g., stx2 alleles, astA, toxB), adhesion factors (i.e. espB_O157, tir, eae), or secretion factors (e.g., espA, espF, espJ, etpD, nleA, nleB, nleC, tccP). Seven genes were associated with prolonged stx shedding; the presence of three genes (lpfA, senB, and stx1) and the absence of four genes (espB_O157, espF, astA, and intI1). We found STEC genes that might predict severe disease outcome already at diagnosis. This can be used to develop diagnostic tools for risk assessment of disease outcome. Furthermore, genes associated with the duration of stx shedding were detected, enabling a possible better prediction of length of STEC carriage after infection.

Staphylococcus aureus colonization related to severity of hand eczema.

Knowledge on Staphylococcus aureus colonization rates and epidemiology in hand eczema is limited. The aim of this study was to clarify some of these issues. Samples were collected by the "glove juice" method from the hands of 59 patients with chronic hand eczema and 24 healthy individuals. Swab samples were taken from anterior nares and throat from 43 of the 59 patients and all healthy individuals. S. aureus were spa typed and analysed by DNA-microarray-based genotyping. The extent of the eczema was evaluated by the hand eczema extent score (HEES). The colonization rate was higher on the hands of hand eczema patients (69 %) compared to healthy individuals (21 %, p < 0.001). This was also seen for bacterial density (p = 0.002). Patients with severe hand eczema (HEES ≥ 13) had a significantly higher S. aureus density on their hands compared to those with milder eczema (HEES = 1 to 12, p = 0.004). There was no difference between patients and healthy individuals regarding colonization rates in anterior nares or throat. spa typing and DNA-microarray-based genotyping indicated certain types more prone to colonize eczematous skin. Simultaneous colonization, in one individual, with S. aureus of different types, was identified in 60-85 % of the study subjects. The colonization rate and density indicate a need for effective treatment of eczema and may have an impact on infection control in healthcare.

Possible transmission of Candida albicans on an intensive care unit: genotype and temporal cluster analyses.

BACKGROUND: Nosocomial transmission of Candida spp. has not been fully explored and previous studies have shown conflicting results. AIM: To evaluate the possible nosocomial transmission of Candida spp. on an intensive care unit (ICU). METHODS: A prospective study was conducted for a period of 19 months, including all patients on our ICU with growth of Candida spp. from surveillance and directed cultures. Molecular typing with repetitive sequence-based polymerase chain reaction was used to define genotype relationships between the Candida albicans and Candida glabrata isolates. Candida isolates obtained from blood cultures taken from patients in our county outside the ICU were used as a reference. Temporal cluster analysis was performed to evaluate genotype distribution over time. FINDINGS: Seventy-seven patients with 78 ICU stays, representing 12% of all ICU stays, were found to harbour 180 isolates of Candida spp. Molecular typing revealed 27 C. albicans genotypes and 10 of C. glabrata. Possible clustering, indicated by overlapping stays of patients with indistinguishable candida genotypes, was observed on seven occasions with C. albicans and on two occasions with C. glabrata. Two C. albicans genotypes were found significantly more often in the ICU group compared with the reference group. Moreover, C. albicans genotypes isolated from more than one patient were significantly more often found in the ICU group. Temporal cluster analysis revealed a significantly increased number of pairs with indistinguishable genotypes at a 21-day interval, indicating clustering. CONCLUSION: This study indicates possible transmission of C. albicans between ICU patients based on genotyping and temporal cluster analysis.

The role of broth enrichment in Staphylococcus aureus cultivation and transmission from the throat to newborn infants: results from the Swedish hygiene intervention and transmission of S. aureus study.

Staphylococcus aureus is detected by direct plating, whereas incubation in enrichment broth prior to plating to increase the proportion of positive samples has not been fully evaluated. S. aureus throat colonization has been suggested to be more common than colonization of the anterior nares, but no data are available on the transmission of S. aureus from the throat. Swab samples were collected from the anterior nares and umbilicus from newborn infants (n = 168), anterior nares, throat, skin lesions, and vagina from parents (n = 332), and anterior nares, throat, and skin lesions from healthcare workers (n = 231) at three maternity wards. spa typing was used to elucidate the transmission routes of S. aureus. The use of enrichment broth prior to plating increased the proportion of positive samples by 46%. The prevalence of S. aureus colonization in adults was 58%. Throat colonization (47%) was significantly more common than colonization in any of the other screened sites (p < 0.001). In total, 103 out of 168 (61%) newborn infants were colonized during their hospital stay. Overall, 124 S. aureus transmissions to newborn infants were detected. Although we detected an increased risk of transmission from the nares as compared to the throat, with an odds ratio of 4.8 [95% confidence interval (CI) 1.8-12.7], we detected a transmission rate of 7 % from the throat. We show that S. aureus throat colonization is more common than colonization in any of the other sites among the parents and staff. We also show evidence of transmission from the throat.