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Shiga toxin-producing Escherichia coli (STEC) infection can cause a broad spectrum of symptoms spanning from asymptomatic shedding to mild and bloody diarrhea (BD) and even life-threatening hemolytic-uremic syndrome (HUS). As a member of the serine protease autotransporters of Enterobacteriaceae (SPATE) family, EspP has the ability to degrade human coagulation factor V, leading to mucosal bleeding, and also plays a role in bacteria adhesion to the surface of host cells. Here, we investigated the prevalence and genetic diversity of espP among clinical STEC isolates from patients with mild diarrhea, BD, and HUS, as well as from asymptomatic individuals, and assessed the presence of espP and its subtypes in correlation to disease severity. We found that 130 out of 239 (54.4%) clinical STEC strains were espP positive, and the presence of espP was significantly associated with BD, HUS, and O157:H7 serotype. Eighteen unique espP genotypes (GTs) were identified and categorized into four espP subtypes, i.e., espP alpha (119, 91.5%), espP gamma (5, 3.8%), espP delta (4, 3.1%), and espP epsilon (2, 1.5%). espP alpha was widely distributed, especially in strains from patients with BD and HUS, and correlated with serotype O157:H7. Serogroup O26, O145, O121, and O103 strains carried espP alpha only. Ten GTs were identified in espP alpha, and espP alpha/GT2 was significantly associated with severe disease, i.e., BD and HUS. Additionally, espP was strongly linked to the presence of eae gene, and the coexistence of espP alpha and stx2/stx2a + stx2c was closely related to HUS status. To sum up, our data demonstrated a high prevalence and genetic diversity of the espP gene in clinical STEC strains in Sweden and revealed an association between the presence of espP, espP subtypes, and disease severity. espP, particularly the espP alpha subtype, was prone to be present in more virulent STEC strains, e.g., "top-six" serotypes strains., Funding Agencies|Scandinavian Society for Antimicrobial Chemotherapy Foundation

This study describes a large nosocomial outbreak of Clostridioides difficile infections (CDI) dominated by ribotype (RT) 046 in a Swedish hospital. The present study aimed to examine the pathogenicity of this RT, explore epidemiological links by whole genome sequencing (WGS), and evaluate different interventions implemented to stop the outbreak. Clinical isolates (n = 366) collected during and after the outbreak were ribotyped and 246 isolates were subjected to WGS. Medical records of patients infected with the seven most common RTs were evaluated. RT046 was spread effectively throughout the hospital and was the most common among the 44 different RTs found (114/366 isolates). Infection with RT046 was associated with higher mortality compared to other strains (20.2% to 7.8%), although there were no differences in concomitant disease, age or antibiotic treatment. To control the outbreak, several measures were successfully implemented., Funding: Academy for Health and Care, Region Jonkoping County, Sweden

Clostridioides difficile infections (CDIs) in Sweden are mostly hospital-associated (HA) with limited knowledge regarding community-associated (CA) infections. Here, we investigated the molecular epidemiology of clinical isolates of CA-CDI and HA-CDI in a Swedish county. Data and isolates (n = 156) of CDI patients (n = 122) from Jonkoping county, October 2017-March 2018, were collected and classified as CA (without previous hospital care or onset <= 2 days after admission or >12 weeks after discharge from hospital) or HA (onset >3 days after hospital admission or within 4 weeks after discharge). Molecular characterization of isolates included PCR ribotyping (n = 156 isolates) and whole genome sequencing with single nucleotide polymorphisms (SNP) analysis (n = 53 isolates). We classified 47 patients (39%) as CA-CDI and 75 (61%) as HA-CDI. Between CA-CDI and HA-CDI patients, we observed no statistically significant differences regarding gender, age, 30-day mortality or recurrence. Ribotype 005 (RR 3.1; 95% CI: 1.79-5.24) and 020 (RR 2.5; 95% CI: 1.31-4.63) were significantly associated with CA-CDI. SNP analysis identified seven clusters (0-2 SNP difference) involving 17/53 isolates of both CA-CDI and HA-CDI. Molecular epidemiology differed between CA-CDI and HA-CDI and WGS analysis suggests transmission of CDI within and between hospitals and communities.

Shiga toxin-producing Escherichia coli (STEC) are important foodborne pathogens that can cause human infections ranging from asymptomatic carriage to bloody diarrhea (BD) and fatal hemolytic uremic syndrome (HUS). However, the molecular mechanism of STEC pathogenesis is not entirely known. Here, we demonstrated a large scale of molecular epidemiology and in-depth genomic study of clinical STEC isolates utilizing clinical and epidemiological data collected in Region Jonkoping County, Sweden, over a 15-year period. Out of 184 STEC isolates recovered from distinct patients, 55 were from patients with BD, and 129 were from individuals with non-bloody stools (NBS). Five individuals developed HUS. Adults were more associated with BD. Serotypes O157:H7, O26:H11, O103:H2, O121:H19, and O104:H4 were more often associated with BD. The presence of Shiga toxin-encoding gene subtypes stx(2a), stx(2a) + stx(2c), and stx(1a) + stx(2c) was associated with BD, while stx(1)(a) was associated with milder disease. Multiplex virulence and accessory genes were correlated with BD; these genes encode toxins, adhesion, autotransporters, invasion, and secretion system. A number of antimicrobial resistance (AMR) genes, such as aminoglycoside, aminocoumarin, macrolide, and fluoroquinolone resistance genes, were prevalent among clinical STEC isolates. Whole-genome phylogeny revealed that O157 and non-O157 STEC isolates evolved from distinct lineages with a few exceptions. Isolates from BD showed more tendency to cluster closely. In conclusion, this study unravels molecular trait of clinical STEC strains and identifies genetic factors associated with severe clinical outcomes, which could contribute to management of STEC infections and disease progression if confirmed by further functional validation., Funding Agencies|Scandinavian Society for Antimicrobial Chemotherapy Foundation [SLS884041]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [81701977]

Since the late 1990s, changes in the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) were recognized with the emergence of community-associated MRSA (CA-MRSA). CA-MRSA belonging to clonal complex 152 (CC152), carrying the small staphylococcal cassette chromosome mec (SCCmec) type V and encoding the Panton-Valentine leukocidin (PVL), has been observed in Europe. The aim of this study was to investigate its origin, evolution, and dissemination. Whole-genome sequencing was performed on a global collection of 149 CC152 isolates spanning 20 years (93 methicillin-susceptible S. aureus [MSSA] and 56 MRSA isolates). Core genome phylogeny, Bayesian inference, in silico resistance analyses, and genomic characterization were applied. Phylogenetic analysis revealed two major distinct clades, one dominated by MSSA and the other populated only by MRSA. The MSSA isolates were predominately from sub-Saharan Africa, whereas MRSA was almost exclusively from Europe. The European MRSA isolates all harbored an SCCmec type V (5C2&5) element, whereas other SCCmec elements were sporadically detected in MRSA from the otherwise MSSA-dominated clade, including SCCmec types IV (2B), V (5C2), and XIII (9A). In total, 93% of the studied CC152 isolates were PVL positive. Bayesian coalescent inference suggests an emergence of the European CC152-MRSA in the 1990s, while the CC152 lineage dates back to the 1970s. The CA-MRSA CC152 clone mimics the European CC80 CA-MRSA lineage by its emergence from a PVL-positive MSSA ancestor from North Africa or Europe. The CC152 lineage has acquired SCCmec several times, but acquisition of SCCmec type V (5C2&5) seems associated with expansion of MRSA CC152 in Europe. IMPORTANCE Understanding the evolution of CA-MRSA is important in light of the increasing importance of this reservoir in the dissemination of MRSA. Here, we highlight the story of the CA-MRSA CC152 lineage using whole-genome sequencing on an international collection of CC1

Introduction: Reliable venous access is a cornerstone in delivery of cytotoxic drugs, and subcutaneous venous ports (SVPs) are commonly used. Pocket infection is a major complication that can lead to SVP removal and treatment delay. Consensus is lacking whether a suspected port infection is a contraindication to continued use. Our aim was to examine the extent of pathogen transfer into a SVP by puncturing an in vitro contaminated injection membrane and to evaluate techniques to reduce this transmission. Method: Four pathogens were applied to SVP membranes in concentrations mimicking clinical infection, and the membranes punctured with or without flow through the needle. The port was then flushed with saline, and samples from the outlet were analyzed. Results: Microorganisms were transported into the SVP when puncturing the contaminated membrane. The number of microorganisms transferred was related to the concentration of microorganisms on the membrane and varied with species. Flow through the needle during insertion reduced the number of bacteria transported through the SVP membrane. Discussion: Our results indicate that a limited number of pathogens are likely to be introduced into the SVP chamber when puncturing a contaminated membrane. The number of bacteria transferred could be reduced by applying flow during puncture.

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 andlt; 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., Funding Agencies|Futurum-the Academy for Healthcare||Jonkoping County Council||Medical Research Council of Southeast Sweden

We present a novel denaturing gradient gel electrophoresis (DGGE) method which characterizes multiclonal communities of Staphylococcus aureus. The spa PCR-based DGGE method simultaneously separates strains that differ in only one base, thereby revealing multiclonal colonization and infections., Funding Agencies|Swedish Society of Medicine||Futurum||Research Council of South-East Sweden (FORSS)

Molecular methods based on sequencing, such as spa typing, have facilitated epidemiological typing of bacterial isolates compared to the gold standard pulsed-field gel electrophoresis (PFGE), a technically more demanding method. We studied methicillin-resistant Staphylococcus aureus (MRSA) in 4 Swedish counties from 2003 through 2005, and compared spa typing and PFGE results to epidemiological data. Of 280 MRSA isolates, 91 were from sporadic cases and 189 were associated with 35 outbreaks. A total of 50 spa types and 74 PFGE patterns were detected. 60 (21%) of the MRSA isolates carried the Panton-Valentine leukocidin (PVL) genes. 12 of the PVL-positive MRSA were healthcare associated. 25 of the spa types and 31 of the PFGE patterns were associated with outbreaks. In 1 of the outbreaks we found isolates with different but closely related spa types, and in 6 of the outbreaks we observed isolates with different but related PFGE patterns. In this low-endemic setting, with outbreaks limited in time and place, we found spa typing to be a useful tool for epidemiological typing of MRSA, due to its rapidity, accessibility, ease of use, and standardized nomenclature.