Extraintestinal Infections Research Articles

Acacia Fiber Protects the Gut from Extended-Spectrum Beta-Lactamase (ESBL)-Producing Escherichia coli Colonization Enabled by Antibiotics.

ABSTRACTNovel approaches to combating antibiotic resistance are needed given the ever-continuing rise of antibiotic resistance and the scarce discovery of new antibiotics. Little is known about the colonization dynamics and the role of intrinsic plant-food characteristics in this process. We sought to determine whether plant fiber could alter colonization dynamics by antibiotic-resistant bacteria in the gut. We determined that ingestion of antibiotics in mice markedly enhanced gut colonization by a pathogenic extended-spectrum beta-lactamase-producing Escherichia coli strain of human origin, E. coli JJ1886 (ST131-H30Rx). Furthermore, ingestion of soluble acacia fiber before and after antibiotic exposure significantly reduced pathogenic E. coli colonization. 16S rRNA analysis and ex vivo cocultures demonstrated that fiber protected the microbiome by serving as a prebiotic, which induced native gut E. coli to inhibit pathogenic E. coli via colicin M. Fiber may be a useful prebiotic with which to administer antibiotics to protect human and livestock gut microbiomes against colonization from antibiotic-resistant, pathogenic bacteria.IMPORTANCE A One Health-based strategy—the concept that human health and animal health are interconnected with the environment—is necessary to determine the drivers of antibiotic resistance from food to the clinic. Moreover, humans can ingest antibiotic-resistant bacteria on food and asymptomatically, or “silently,” carry such bacteria in the gut long before they develop an opportunistic extraintestinal infection. Here, we determined that fiber-rich foods, in particular acacia fiber, may be a new, promising, and inexpensive prebiotic to administer with antibiotics to protect the mammalian (i.e., human and livestock) gut against such colonization by antibiotic-resistant, pathogenic bacteria.

Characterisation of Salmonella Enteritidis ST11 and ST1925 Associated with Human Intestinal and Extra-Intestinal Infections in Singapore.

Salmonella Enteritidis is a major foodborne pathogen worldwide. In this study, a total of 276 S. enteritidis isolates, collected between 2016 and 2017 from human, food and farm/slaughterhouse samples, were studied to enhance the understanding of the epidemiology of human salmonellosis in Singapore. Results showed all 276 isolates belonged either to ST1925 (70.3%) or ST11 (29.7%), with ST11 being significantly more frequent in extra-intestinal isolates and chicken isolates. Food isolates, most of which were from poultry, showed the highest prevalence of resistance (33–37%) against beta-lactams or beta-lactams/beta-lactamase inhibitor combination (ampicillin, piperacillin and ampicillin/sulbactam). The analysis showed the detection of genes associated with resistance to aminoglycoside genes (99.6%), tetracycline (55.1%), and beta-lactams (14.9%) of all isolates. Nine types of plasmids were found in 266 isolates; the most common incompatibility group profiles were IncFIB(S)-IncFII(S)-IncX1 (72.2%) and IncFIB(S)-IncFII(S) (15.8%). Most plasmid harbouring isolates from chicken (63.6%, 14/22) and from human (73.8%, 175/237) shared the same plasmid profile (IncFIB(S)-IncFII(S)-IncX1). SNP analysis showed clustering of several isolates from poultry food products and human isolates, suggesting phylogenetic relatedness among these isolates. Lastly, this study provides important epidemiological insights on the application of phenotypic and next-generation sequencing (NGS) tools for improved food safety and public health surveillance and outbreak investigation of S. enteritidis.

Genome and virulome characterization of Escherichia coli encoding multiple antimicrobial resistance genes isolated from commercial dairy operations

The aim of this study was to describe the genome sequences of 12 Escherichia coliisolates that encode antimicrobial resistance genes (ARGs) and were isolated from composite dairy animal faecal samples. The isolates were recovered between 2013 and 2014 from a larger study evaluating the presence of resistance on dairy operations in Pennsylvania, USA. The draft genomes were sequenced on an Illumina NextSeq 500 platform and were assembled using SPAdes. In total, 69 ARGs were identified, and these were categorized into 20 unique genes conferring resistance to eight classes of antimicrobials. In order of decreasing frequency of detection, these classes were aminoglycosides, tetracyclines, sulphonamides, β-lactams, phenicols, trimethoprim, fosfomycin, and macrolide-lincosamide-streptogramin B (MLS). Among the resistant isolates, 11 sequence types (ST) were identified, with ST86 detected twice. Although pathogenicity was not evaluated in vivo, multiple genomes encoded virulence factors involved in severe gastrointestinal and extraintestinal infections, including a single Shiga-toxigenic isolate. The results of this study demonstrate the presence of antimicrobial-resistant E. coli in dairy animal faeces encoding virulence factors involved in severe human infections.

"Parenteral" Diarrhea Associated With Pediatric Urinary Tract Infections: A Retrospective Chart Review.

The association of noninfectious diarrhea with extraintestinal infections such as otitis media, pneumonia, or febrile urinary tract infections (UTIs) is commonly known as parenteral diarrhea. Although this association has been described for over a century and parenteral diarrhea is mentioned in current reference literature, available evidence for this association seems to be limited. The primary research question was to determine if there is an association between UTIs and reports of diarrhea. A retrospective chart review was performed using the medical records from October 1, 2017, to March 29, 2019 at our tertiary pediatric medical center. We searched for all cases of afebrile and febrile UTIs evaluated in the pediatric emergency department or admitted directly to the hospital for treatment. All children younger than 5 years were eligible for inclusion. Exclusion criteria included children with recent urological procedures, known urinary tract disease, immune suppression, sepsis, or known gastrointestinal diseases. The medical records of each of the pediatric patients with culture-positive UTIs were reviewed for reports of concurrent diarrhea or diarrhea-like illness. In addition, using a comparative quantitative design, we performed a retrospective chart review of all children younger than 5 years with 1 of 2 noninfectious chief complaints, head trauma, and extremity fractures, presenting during the same period to assess the background rate of reported diarrhea.This research project received the approval of the University of South Alabama's Institutional Review Board. A total of 236 children with a culture-positive UTI presented to our pediatric medical center from October 1, 2017 to March 29, 2019. Reports of diarrhea were documented in the medical record for 44 of the 236 UTIs (18.6%). Escherichia coli was the predominant infectious agent in 32 of the 44 children (72.7%) with culture-positive UTIs and diarrhea. Of the 368 comparison group patients who visited the pediatric emergency department for a noninfectious complaint, diarrhea was reported in 2 patients (0.01%). Our retrospective review of pediatric patients younger than 5 years with culture-proven UTIs found an association of reported diarrhea. It is our opinion based on our single-center retrospective chart review that the current available evidence suggests an association between UTIs and extraintestinal diarrhea. Future prospective studies are recommended to confirm this association.

A rare case of extraintestinal amebiasis

BackgroundAmoebiasis is caused by the protozoan Entamoeba histolytica, which is a rare infectious disease in developed countries. If the trophozoites enter the blood, it can spread through the body, such as brain, and lungs. Cases of simultaneous infection of multiple organs are extremely rare.Case presentationHere we report a case of simultaneous infection of amoeba in pulmonary pleura, urinary system and central nervous system. Although the patient received anti amoeba treatment, the prognosis of the patient was poor.ConclusionsIn this patient, multiple extraintestinal amebic infections in the absence of clinically confirmed intestinal amebiasis or amebic liver abscess are rare and pose diagnostic challenges. The disseminated amebiasis has significantly increased the mortality. Early diagnosis and appropriate treatment may reduce the mortality of disseminated amebiasis.

Fuzzy SEIR Epidemic Model of Amoebiasis Infection in Human

Amoebiasis is a disease caused by the protozoan Entamoeba histolytica. It is often asymptomatic but may cause dysentery and invasive extraintestinal infection in humans. To gain an understanding of the disease, a fuzzy SEIR model of amoebiasis infection is presented with the fuzziness introduced in the disease transmission rate, the disease-induced death rate, and the rate of recovery from infection. The basic reproduction number ℛ 0 v is computed and used to make a comparison with the fuzzy basic reproduction number ℛ 0 f at different amounts of cysts as well as to analyse the stability of equilibrium points. Stability results indicate that the disease-free equilibrium and the endemic equilibrium are locally and globally asymptotically stable. Further, numerical simulations are carried out to illustrate the analytical results of the fuzzy model system. The result shows that whenever there is an outbreak, the disease is likely to persist in the first month and thereafter it will start to slow down to disease-free equilibrium.

Relapsing cellulitis associated with Campylobacter coli bacteremia in a Good\u2019s syndrome patient: a case report

BackgroundGood’s syndrome (GS) is characterized by immunodeficiency, and patients diagnosed with GS are susceptible to infection or even bacteremia, which is the most evident complication. Campylobacter coli (C. coli) rarely causes bacteremia or extraintestinal infection. We report herein a case with GS in which right leg cellulitis associated with C. coli bacteremia occurred three times over one and a half years.Case presentationA 41-year-old Chinese male with GS was diagnosed with C. coli infection. He presented with swelling and redness of right lower leg and developed bacteremia due to C. coli repeatedly. Bacteremia was confirmed by bacteriological examination. Adding long-term oral antibiotic treatment with amoxicillin/clavulanate potassium and gentamicin following intravenous meropenem and amikacin was very effective. The blood cultures became negative and the patient has been free from any symptoms encountered for more than one year without relapse of bacteremia.ConclusionsPatients with GS and their physicians should carefully consider the antibacterial treatment options against C. coli bacteremia. Combined anti-infective therapy involving aminoglycoside is preferred in the treatment of C. coli bacteremia in GS patients.

Elderly Patients with Moderate-To-Severe Ulcerative Colitis Are More Likely to Have Treatment Failure and Adverse Outcome

Background and Aim: The aim of this study was to compare therapeutic responses and prognosis between elderly and nonelderly ulcerative colitis (UC) patients with moderate-to-severe activity. Methods: 148 UC patients with moderate-to-severe activity hospitalized between 2000 and 2019 were enrolled consecutively, including 74 patients with the age of diagnosis over 60 years and 74 patients diagnosed less than 60 years. Patients were matched by gender, duration (±15%), disease activity, and admission time (±1 year). They were followed up until the latest medical record or December 2019. The primary outcome was UC-related colectomy or death. Results: 148 patients were followed over median 37.5 months. For steroid use, 76.8% of elderly UC patients were responsive, lower than that in adult group (85.7%). A decreased level of clinical activity index (2.0 [−1.5 to 4.00] vs. 6.0 [3.0–8.0], p < 0.001), reduction of C-reactive protein (23.9 [3.5–65.5] vs. 27.8 [9.7–58.1] mg/L), and erythrocyte sedimentation rate (9.0 [−1.3 to 30.5] vs. 15.5 [3.8–36.5] mm/h) at 4 weeks after steroid induction was less obvious in the elderly. More elderly patients manifested steroid dependence and resistance. 28.4% of elderly UC patients took colectomy, remarkably more than adult patients (12.2%), which also occurred earlier (8.0 [0.5–44.75] vs. 39.5 [12–57.38] months, p = 0.001). Aging (hazard ratio [HR] 2.868, 95% confidence interval [CI]: 1.290–6.375, p = 0.01), male, steroid resistance, and occurrence of complications were independently related to colectomy. The rate of serious infections was significantly higher in the elderly (55.4% vs. 35.1%, p = 0.013), mainly including cytomegalovirus infection, bacterial infection, and extraintestinal infection. Aging (odds ratio [OR] 2.774, 95% CI: 1.355–5.675, p = 0.015), extensive colonic involvement, steroid resistance, and biologics usage were independently associated with a high risk of concomitant infections. Conclusion: Elderly patients with moderate-to-severe UC experienced more treatment failure and increased risk of UC-related colectomy, mortality, and severe infections, predicting demand for more strict and individualized management.

Case report: post-salmonellosis abscess positive for Salmonella Oranienburg

BackgroundSalmonella gastroenteritis is a self-limited infection in immunocompetent adults. Salmonella Oranienburg is a serovar that has recently caused outbreaks of gastroenteritis traced to contact with a pet turtle. Extraintestinal focal infections (EFIs) with invasive Salmonella have been reported uncommonly, examples of which include mycotic aneurysm and spinal osteomyelitis.Case presentationThe patient is an otherwise healthy 39-year-old male with sleep apnea presenting with pain and swelling in the left anterior chest wall several months after an episode of Salmonella gastroenteritis and bacteremia which was treated successfully with intravenous (IV) antibiotics. He was found to have a costochondral joint abscess with operative cultures positive for S. Oranienburg, a serovar reported to have been associated with pet turtles and onions in recent CDC and FDA news releases. Of note, the joint abscess began development 2–3 months after his episode of Salmonella bacteremia. At the time of surgical treatment, nearly 6 months had passed since the initial episode of gastroenteritis and bacteremia.ConclusionsDelayed development of a sternocostal joint abscess after Salmonella bacteremia in an otherwise healthy adult male is an unusual presentation. The patient had two different exposures: a fast food chicken lunch and a pet turtle at home. Extraintestinal focal infections with invasive Salmonella are very uncommonly reported in healthy adult patients treated in developed countries. To our knowledge, we report this sequala for the first time.

Molecular characterization and antimicrobial resistance profile of pathogenic Escherichia coli from goats with respiratory disease in eastern China

Pathogenic Escherichia coli (E. coli) can cause a variety of intestinal and extra-intestinal infections in humans and animals. Similar with the intestinal disease, respiratory disease is also a major threat to the breeding industry of goats. But the reports on respiratory disease associated E. coli are very limited. In this study, E. coli and other pathogens were examined for the 77 submitted respiratory cases. The serotypes, virulence genes, phylogenetic group and antimicrobial resistance characteristics of the E. coli isolates were identified. The results showed that 34 cases (44.16%) were associated with E. coli and 22 cases showed mixed infections of E. coli with Mycoplasma ovipneumoniae, Mannheimia haemolytica or Pasteurella . Among the 49 E. coli isolates, O8 (32.65%), O9 (20.41%) and O89 (10.20%) were the predominant serotypes (31/49, 63.27%). 22 virulence genes were detected and the most prevalent genes were fimH (100%), yijp (100%), mat (97.96%), ompA (95.92%) ibeB (91.84%) and fyuA (77.55%). In addition, ibeA was detected in 6.12% (3/49) of the strains. Markers of extra-intestinal pathogenic E. coli (ExPEC) were also identified and 14 strains were classified as ExPECs. 14 (28.57%), 25 (51.02%), 3 (6.12%) and 7 (14.29%) strains belonged to phylogenetic group A, B1, B2 and D, respectively, and group A and B1 were the predominant ones. The E. coli strains showed high resistant (48.98%–100%) to the 14 selected antimicrobials and all of them were defined as multiple drug resistant (MDR) strains. This is the first systemically study on E. coli of goats respiratory diseases origin in eastern China. The results suggest that E. coli infection may play an important role in goat respiratory diseases and that goats are reservoir hosts of ExPECs, which needs continuous monitoring in the future.

Use of Nanopore Sequencing to Characterise the Genomic Architecture of Mobile Genetic Elements Encoding bla CTX-M-15 in Escherichia coli Causing Travellers' Diarrhoea.

Increasing levels of antimicrobial resistance (AMR) have been documented in Escherichia coli causing travellers’ diarrhoea, particularly to the third-generation cephalosporins. Diarrhoeagenic E. coli (DEC) can act as a reservoir for the exchange of AMR genes between bacteria residing in the human gut, enabling them to survive and flourish through the selective pressures of antibiotic treatments. Using Oxford Nanopore Technology (ONT), we sequenced eight isolates of DEC from four patients’ specimens who had all recently returned to the United Kingdome from Pakistan. Sequencing yielded two DEC harbouring blaCTX-M-15 per patient, all with different sequence types (ST) and belonging to five different pathotypes. The study aimed to determine whether blaCTX-M-15 was located on the chromosome or plasmid and to characterise the drug-resistant regions to better understand the mechanisms of onward transmission of AMR determinants. Patients A and C both had one isolate where blaCTX-M-15 was located on the plasmid (899037 & 623213, respectively) and one chromosomally encoded (899091 & 623214, respectively). In patient B, blaCTX-M-15 was plasmid-encoded in both DEC isolates (786605 & 7883090), whereas in patient D, blaCTX-M-15 was located on the chromosome in both DEC isolates (542093 & 542099). The two blaCTX-M-15-encoding plasmids associated with patient B were different although the blaCTX-M-15-encoding plasmid isolated from 788309 (IncFIB) exhibited high nucleotide similarity to the blaCTX-M-15-encoding plasmid isolated from 899037 (patient A). In the four isolates where blaCTX-M-15 was chromosomally encoded, two isolates (899091 & 542099) shared the same insertion site. The blaCTX-M-15 insertion site in isolate 623214 was described previously, whereas that of isolate 542093 was unique to this study. Analysis of Nanopore sequencing data enables us to characterise the genomic architecture of mobile genetic elements encoding AMR determinants. These data may contribute to a better understanding of persistence and onward transmission of AMR determinants in multidrug-resistant (MDR) E. coli causing gastrointestinal and extra-intestinal infections.

Outer membrane vesicles produced by pathogenic strains of Escherichia coli block autophagic flux and exacerbate inflammasome activation

Escherichia coli strains are responsible for a majority of human extra-intestinal infections, resulting in huge direct medical and social costs. We had previously shown that HlyF encoded by a large virulence plasmid harbored by pathogenic E. coli is not a hemolysin but a cytoplasmic enzyme leading to the overproduction of outer membrane vesicles (OMVs). Here, we showed that these specific OMVs inhibit the macroautophagic/autophagic flux by impairing the autophagosome-lysosome fusion, thus preventing the formation of acidic autolysosomes and autophagosome clearance. Furthermore, HlyF-associated OMVs were more prone to activate the non-canonical inflammasome pathway. Because autophagy and inflammation are crucial in the host’s response to infection especially during sepsis, our findings revealed an unsuspected role of OMVs in the crosstalk between bacteria and their host, highlighting the fact that these extracellular vesicles have exacerbated pathogenic properties.

Virulome and genome analyses identify associations between antimicrobial resistance genes and virulence factors in highly drug-resistant Escherichia coli isolated from veal calves.

Food animals are known reservoirs of multidrug-resistant (MDR) Escherichia coli, but information regarding the factors influencing colonization by these organisms is lacking. Here we report the genomic analysis of 66 MDR E. coli isolates from non-redundant veal calf fecal samples. Genes conferring resistance to aminoglycosides, β-lactams, sulfonamides, and tetracyclines were the most frequent antimicrobial resistance genes (ARGs) detected and included those that confer resistance to clinically significant antibiotics (blaCMY-2, blaCTX-M, mph(A), erm(B), aac(6’)Ib-cr, and qnrS1). Co-occurrence analyses indicated that multiple ARGs significantly co-occurred with each other, and with metal and biocide resistance genes (MRGs and BRGs). Genomic analysis also indicated that the MDR E. coli isolated from veal calves were highly diverse. The most frequently detected genotype was phylogroup A-ST Cplx 10. A high percentage of isolates (50%) were identified as sequence types that are the causative agents of extra-intestinal infections (ExPECs), such as ST69, ST410, ST117, ST88, ST617, ST648, ST10, ST58, and ST167, and an appreciable number of these isolates encoded virulence factors involved in the colonization and infection of the human urinary tract. There was a significant difference in the presence of multiple accessory virulence factors (VFs) between MDR and susceptible strains. VFs associated with enterohemorrhagic infections, such as stx, tir, and eae, were more likely to be harbored by antimicrobial-susceptible strains, while factors associated with extraintestinal infections such as the sit system, aerobactin, and pap fimbriae genes were more likely to be encoded in resistant strains. A comparative analysis of SNPs between strains indicated that several closely related strains were recovered from animals on different farms indicating the potential for resistant strains to circulate among farms. These results indicate that veal calves are a reservoir for a diverse group of MDR E. coli that harbor various resistance genes and virulence factors associated with human infections. Evidence of co-occurrence of ARGs with MRGs, BRGs, and iron-scavenging genes (sit and aerobactin) may lead to management strategies for reducing colonization of resistant bacteria in the calf gut.

Regulation of Escherichia coli Group 2 Capsule Gene Expression: A Mini Review and Update.

The expression of a group 2 capsule (K antigen), such as the K1 or K5 antigen, is a key virulence factor of Escherichia coli responsible for extra-intestinal infections. Capsule expression confers resistance to innate host defenses and plays a critical role in invasive disease. Capsule expression is temperature-dependent being expressed at 37°C but not at 20°C when outside the host. Group 2 capsule gene expression involves two convergent promoters PR1 and PR3, the regulation of which is critical to capsule expression. Temperature-dependent expression is controlled at transcriptional level directly by the binding of H-NS to PR1 and PR3 and indirectly through BipA with additional input from IHF and SlyA. More recently, other regulatory proteins, FNR, Fur, IHF, MprA, and LrhA, have been implicated in regulating capsule gene expression in response to other environmental stimuli and there is merging data for the growth phase-dependent regulation of the PR1 and PR3 promoters. The aim of the present Mini Review is to provide a unified update on the latest data on how the expression of group 2 capsules is regulated in response to a number of stimuli and the growth phase something that has not to date been addressed.

Extended-Spectrum Beta-Lactamase- and Carbapenemase-Producing Enterobacteriaceae Family of Bacteria from Diarrheal Stool Samples in Northwest Ethiopia.

Background Resistance among the commensal flora is a serious threat because they are highly populated ecosystems like the gut, maybe a source of extraintestinal infections. Infections due to extended-spectrum beta-lactamase (ESBL)- and carbapenemase (CPM)-producing Enterobacteriaceae family of bacteria impose a major global issue because they are usually resistant to multiple antimicrobial agents. Data on the fecal ESBL- and CPM-producing group of bacteria in developing countries including Ethiopia are limited mainly due to resource constraints. Thus, this study aimed to determine the prevalence of multidrug-resistant (MDR)-, ESBL-, and CPM-producing Enterobacteriaceae family of bacteria from diarrheal stool samples at the University Hospital, Northwest Ethiopia. Materials and Methods A hospital-based cross-sectional study was conducted involving a total of 384 study participants having gastrointestinal complaints from January to April 2019. A diarrheal stool sample was aseptically collected and inoculated on a MacConkey agar plate. After getting pure colonies, biochemical and antimicrobial susceptibility testing was done following standard microbiological techniques. ESBL production was screened using ceftazidime and cefotaxime and confirmed using a combined disk diffusion test. Carbapenemases were screened by meropenem disk and confirmed by the modified carbapenem inactivation method. Data were checked, cleaned, and entered using Epi Info version 7.1 and transferred to SPSS version 20 for analysis. Result A total of 404 Enterobacteriaceae groups of bacteria were isolated from 384 diarrheal stool samples. The overall prevalence of fecal MDR-, ESBL-, and CPM-producing group of Enterobacteriaceae was 196 (48.5%), 66 (16.3%), and 4 (1%), respectively. Of the total ESBL-producing Enterobacteriaceae, E. coli (41/66 (62.1%)) and K. pneumoniae (18/66 (27.3%)) were the most predominant isolates. One half of CPE has been observed in Citrobacter species and the rest in E. coli (25%) and P. vulgaris (25%). Conclusion and Recommendation. Finding the high rate of ESBL-producing Enterobacteriaceae and CPE requires strict infection control measures and careful selection of empirical therapy in the study area. Therefore, active surveillance with large sample size and better infection prevention control is needed.

Case-Control Study of Clostridium innocuum Infection, Taiwan.

Vancomycin-resistant Clostridium innocuum was recently identified as an etiologic agent for antibiotic-associated diarrhea in humans. We conducted a case–control study involving 152 C. innocuum-infected patients during 2014–2019 in Taiwan, using 304 cases of Clostridioides difficile infection (CDI) matched by diagnosis year, age (+2 years), and sex as controls. The baseline characteristics were similar between the 2 groups. C. innocuum–infected patients experienced more extraintestinal clostridial infection and gastrointestinal tract–related complications than did patients with CDI. The 30-day mortality rate among C. innocuum–infected patients was 14.5%, and the overall rate was 23.0%. Chronic kidney disease, solid tumor, intensive care unit admission, and shock status were 4 independent risk factors for death. C. innocuum identified from clinical specimens should be recognized as a pathogen requiring treatment, and because of its intrinsic vancomycin resistance, precise identification is necessary to guide appropriate and timely antimicrobial therapy.

Case–Control Study of Clostridium innocuum Infection, Taiwan

Abstract Vancomycin-resistant Clostridium innocuum was recently identified as an etiologic agent for antibiotic-associated diarrhea in humans. We conducted a case–control study involving 152 C. innocuum-infected patients during 2014–2019 in Taiwan, using 304 cases of Clostridioides difficile infection (CDI) matched by diagnosis year, age (+2 years), and sex as controls. The baseline characteristics were similar between the 2 groups. C. innocuum–infected patients experienced more extraintestinal clostridial infection and gastrointestinal tract–related complications than did patients with CDI. The 30-day mortality rate among C. innocuum–infected patients was 14.5%, and the overall rate was 23.0%. Chronic kidney disease, solid tumor, intensive care unit admission, and shock status were 4 independent risk factors for death. C. innocuum identified from clinical specimens should be recognized as a pathogen requiring treatment, and because of its intrinsic vancomycin resistance, precise identification is necessary to guide appropriate and timely antimicrobial therapy.

A Pain in the Neck: An Adolescent with Neck Pain.

A Pain in the Neck: An Adolescent with Neck Pain.

Population genomics of the food-borne pathogen Vibrio fluvialis reveals lineage associated pathogenicity-related genetic elements.

Vibrio fluvialis is a food-borne pathogen with epidemic potential that causes cholera-like acute gastroenteritis and sometimes extraintestinal infections in humans. However, research on its genetic diversity and pathogenicity-related genetic elements based on whole genome sequences is lacking. In this study, we collected and sequenced 130 strains of V. fluvialis from 14 provinces of China, and also determined the susceptibility of 35 of the strains to 30 different antibiotics. Combined with 52 publicly available V. fluvialis genomes, we inferred the population structure and investigated the characteristics of pathogenicity-related factors. The V. fluvialis strains exhibited high levels of homologous recombination and were assigned to two major populations, VflPop1 and VflPop2, according to the different compositions of their gene pools. VflPop2 was subdivided into groups 2.1 and 2.2. Except for VflPop2.2, which consisted only of Asian strains, the strains in VflPop1 and VflPop2.1 were distributed in the Americas, Asia and Europe. Analysis of the pathogenicity potential of V. fluvialis showed that most of the identified virulence-related genes or gene clusters showed high prevalence in V. fluvialis , except for three mobile genetic elements: pBD146, ICEVflInd1 and MGIVflInd1, which were scattered in only a few strains. A total of 21 antimicrobial resistance genes were identified in the genomes of the 182 strains analysed in this study, and 19 (90%) of them were exclusively present in VflPop2. Notably, the tetracycline resistance-related gene tet(35) was present in 150 (95%) of the strains in VflPop2, and in only one (4%) strain in VflPop1, indicating it was population-specific. In total, 91% of the 35 selected strains showed resistance to cefazolin, indicating V. fluvialis has a high resistance rate to cefazolin. Among the 15 genomes that carried the previously reported drug resistance-related plasmid pBD146, 11 (73%) showed resistance to trimethoprim-sulfamethoxazole, which we inferred was related to the presence of the dfr6 gene in the plasmid. On the basis of the population genomics analysis, the genetic diversity, population structure and distribution of pathogenicity-related factors of V. fluvialis were delineated in this study. The results will provide further clues regarding the evolution and pathogenic mechanisms of V. fluvialis , and improve our knowledge for the prevention and control of this pathogen.

Aeromonas sobria Serine Protease Degrades Several Protein Components of Tight Junctions and Assists Bacterial Translocation Across the T84 Monolayer.

Aeromonas sobria is a Gram-negative pathogen that causes food-borne illness. In immunocompromised patients and the elderly, A. sobria opportunistically leads to severe extraintestinal diseases including sepsis, peritonitis, and meningitis. If A. sobria that infects the intestinal tract causes such an extraintestinal infection, the pathogen must pass through the intestinal epithelial barrier. In our earlier study using intestinal cultured cells (T84 cells), we observed that an A. sobria strain with higher A. sobria serine protease (ASP) production caused a marked level of bacterial translocation across the T84 intestinal epithelial monolayer. Herein, we investigated the effect of ASP on tight junctions (TJs) in T84 cells. We observed that ASP acts on TJs and causes the destruction of ZO-1, ZO-2, ZO-3, and claudin-7 (i.e., some of the protein components constituting TJs), especially in the strains with high ASP productivity. Based on the present results together with those of our earlier study, we propose that ASP may cause a disruption of the barrier function of the intestinal epithelium as a whole due to the destruction of TJs (in addition to the destruction of adherens junctions) and that ASP may assist invasion of the pathogens from the intestinal epithelium into deep sites in the human body.