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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. [ABSTRACT FROM AUTHOR]

In 500 children aged ≤10 years after 13-valent pneumococcal conjugate vaccine (PCV)13 immunisation in different schedules, serotypes 19A-specific and 19F-specific immunoglobulin G (IgG) were predicted to persist above 0.35 µg/mL for ≥10 years in all groups, likely due to PCV13-induced memory with natural boosting from residual diseases and colonisation. Generally, serotype-specific IgG could persist above 0.35 µg/mL longer (≥5 years) in the catch-up group than in the 2+1 and 3+1 immunisation groups. 14.5% of the carriage isolates belonged to PCV13 serotypes; statistical analysis revealed that a high serum IgG level (>10.96 µg/mL) will be required to eliminate the point-prevalence nasopharyngeal carriage of serotype 19A. [ABSTRACT FROM AUTHOR]

Salmonella infection is most common in patients with infected aortic aneurysm, especially in Asia. When the aortic wall is heavily atherosclerotic, the intima is vulnerable to invasion by Salmonella, leading to the development of infected aortic aneurysm. By using THP-1 macrophage-derived foam cells to mimic atherosclerosis, we investigated the role of three Salmonella enterica serotypes -- Typhimurium, Enteritidis, and Choleraesuis -- in foam cell autophagy and inflammasome formation. Herein, we provide possible pathogenesis of Salmonella- associated infected aortic aneurysms. Three S. enterica serotypes with or without virulence plasmid were studied. Through Western blotting, we investigated cell autophagy induction and inflammasome formation in Salmonella-infected THP-1 macrophage-derived foam cells, detected CD36 expression after Salmonella infection through flow cytometry, and measured interleukin (IL)-1β, IL-12, and interferon (IFN)-α levels through enzyme-linked immunosorbent assay. At 0.5 h after infection, plasmid-bearing S. Enteritidis OU7130 induced the highest foam cell autophagy -- significantly higher than that induced by plasmid-less OU7067. However, plasmid-bearing S. Choleraesuis induced less foam cell autophagy than did its plasmid-less strain. In foam cells, plasmid-less Salmonella infection (particularly S. Choleraesuis OU7266 infection) led to higher CD36 expression than did plasmid-bearing strains infection. OU7130 and OU7266 infection induced the highest IL-1β secretion. OU7067-infected foam cells secreted the highest IL-12p35 level. Plasmid-bearing S. Typhimurium OU5045 induced a higher IFN-α level than did other Salmonella serotypes. Salmonella serotypes are correlated with foam cell autophagy and IL-1β secretion. Salmonella may affect the course of foam cells formation, or even aortic aneurysm, through autophagy. [ABSTRACT FROM AUTHOR]

Background: Norovirus (NoV) GII.4 is the most common genotype for norovirus gastroenteritis worldwide. New variants or subgenotypes are continuously emerging, thus posing a serious threat to child health. Methods: We compared retrospectively the clinical manifestations and complications of norovirus gastroenteritis in children from April, 2004 through December, 2012. NoV variants were analyzed to investigate the association of circulating viral strains with the complications. A modified disease severity score system based on Vesikari score system was devised and to evaluate disease severity. Results: Compared to the outbreak in 2004/2005 winter, significant higher incidence of complications in the later periods are: convulsive disorder (ρ < 0.001) in 2006/2007 winter gastrointestinal hemorrhage (ρ = 0.047) and severe abdominal pain or irritability (ρ = 0.033) in 2008/09/10 winter; gastrointestinal hemorrhage (ρ = 0.030), severe abdominal pain or irritability (ρ = 0.014), and prominent hyperthermia (fever >39 °C, p = 0.001) in 2011/2012 winter. GII.4 Den_Haag_2006b, GII.4 2010, GII.4 Sydney 2012, and GII.4 2012b were the predominant strains in the outbreaks after 2006. By the modified severity score system, severe norovirus disease occurred in 28.5 %, 32 %, 33.3 %, and 30. 2 % of the patients in the four periods. A longer duration of hospitalization (ρ = 0.02) were found in those with high score irrespective of the year of admission. Conclusions: Our study demonstrated NoV outbreaks in northern Taiwan caused by different GII.4 variants that were associated with specific complications and uncommon clinical presentations. A modified severity score system first proposed in this study was able to identify severe cases with a longer hospital stay in NoV-infected children. [ABSTRACT FROM AUTHOR]

The use of pneumococcal vaccine plays an important role for prevention of invasive pneumococcal disease (IPD). However, introducing the pneumococcal vaccine into the national immunization program (NIP) is complex and costly. The strategy of progressively integrating the pneumococcal conjugate vaccine (PCV) into the NIP in Taiwan provides valuable experience for policy makers. The 7-valent PCV (PCV7) was first available in Taiwan in late 2005. PCV7 was first provided free to children with underlying diseases, those in vulnerable socioeconomic status, and those with inadequate health care resources. The catch-up immunization program with the 13-valent PCV was launched in 2013 and the national pneumococcal immunization program was implemented in 2015. Children aged 2-5 years had the highest incidence of IPD among pediatric population in Taiwan. Although the incidence of IPD caused by PCV7 serotypes has declined, the overall incidence of IPD remained high in the context of PCV7 use in the private sector. A surge of IPD caused by serotype 19A occurred, accounting for 53.6% of IPD cases among children aged ≤ 5 years in 2011-2012. After the implementation of the national pneumococcal immunization program, serogroup 15 has become the leading serogroup for IPD in children. Continued surveillance is necessary to monitor the serotype epidemiology in Taiwan. [ABSTRACT FROM AUTHOR]

Background The green fluorescence protein (GFP)-associated fluorescence method and the luciferaseassociated bioluminescence method are the two major methods for IVIS imaging system to investigate the bacterial infection in animal models. The aim of this study was to evaluate the infection route of Gram-negative bacteria carrying a stable and broad range of conjugative bioluminescence plasmid pSE-Lux1 in a mouse model. Results Both encapsulated and non-encapsulated Gram-negative bacteria were used as hosts to evaluate conjugation efficiency and plasmid stability of pSE-Lux1, a recombinant of pSE34 and luxABCDE operon. The plasmid conjugation efficiencies of pSE-Lux1 ranged from 10-3 to 10-7 in various Gram-negative bacteria. Plasmid pSE-Lux1 maintained in Escherichia coli, Klebsiella pneumoniae, and Salmonella enterica serovars Choleraesues (abbreviated S. Choleraesuis) and Typhimurium (S. Typhimurium), than in Acinetobacter baumannii and Serratia marcescens, was shown to be of better stability for at least four days. To investigate systemic bacterial infections, K. pneumoniae T strain CG354 was intravenous injected and was non-pathogenic to Balb/c mice for a long-term bioluminescence monitoring for 6 days. For examining dynamic distributions of gastrointestinal tract infection, the invasion protein SipB-deficient mutant OU5045ΔsipB and OU5046ΔsipB of Salmonella enterica serovar Typhimurium constructed in this study, compared to wild-type strain OU5045 and its virulence plasmid-less strain OU5046, were of less virulence to mice. Conclusions This is the first study to evaluate the conjugative and stable bioluminescence vehicle system of pSE-Lux1 in a wide range of Gram-negative bacteria, which system can provide a useful reporter approach to trace systemic and gastrointestinal bacterial infections in a mouse model. [ABSTRACT FROM AUTHOR]

In Taiwan, despite a substantial decline of Salmonella enterica serotype Choleraesuis infections, strains resistant to ciprofloxacin and ceftriaxone persist. A self-transferable blaCMY-2-harboring IncI1 plasmid was identified in S. enterica serotypes Choleraesuis, Typhimurium, Agona, and Enteritidis and contributed to the overall increase of ceftriaxone resistance in salmonellae. [ABSTRACT FROM AUTHOR]

Salmonella enterica serotype Enteritidis infection remains a serious public health threat to humans. Salmonella Enteritidis phage type 4 (PT4) is a clone that has already caused a global pandemic for years. To investigate why PT34 becomes a subdominantly emerging phage type, molecular characterizations, including serotyping, pulsed-field gel electrophoresis (PFGE), phage typing, and plasmid profiling, were carried out on PT34. The results indicated that relative to PT4, PT34 contained an additional 32-kb DNA segment in PFGE and a 33-kb plasmid pSE34 in plasmid profiling. Southern blot hybridization showed that the DNA segment was the major part of pSE34. All of the S. Enteritidis PT34 clinical isolates possessed pSE34, while PT4 and PT21 did not. Sequencing analysis revealed that pSE34 is 32 950 bp long, with a G+C% content of 41.2%, and contains a total of 53 orfs. Transposon mutagenesis demonstrated that taxB, taxC, and the pilX operon on this plasmid participated in the process of conjugation. In virulence testing, PT34 that harbored pSE34, compared with PT4, showed no increased invasion to tissue culture cells in vitro. The presence of conjugative pSE34 in PT4 caused the conversion of phage type from PT4 to PT34, suggesting that the emergence of PT34 was a result of the introduction of the conjugative pSE34 into its common progenitor PT4. [ABSTRACT FROM AUTHOR]

The three N-terminal, tandemly arranged LysM motifs from a Bacillus subtilis cell wall hydrolase, LytE, formed a cell wall-binding module. This module, designated CWBMLytE, was demonstrated to have tight cell wall-binding capability and could recognize two classes of cell wall binding sites with fivefold difference in affinity. The lower-affinity sites were approximately three times more abundant. Fusion proteins with β-lactamase attached to either the N- or C-terminal end of CWBMLytE showed lower cell wall-binding affinity. The number of the wall-bound fusion proteins was less than that of CWBMLytE. These effects were less dramatic with CWBMLytE at the N-terminal end of the fusion. Both CWBMLytE and β-lactamase were essentially functional whether they were at the N- or C-terminal end of the fusion. In the optimal case, 1.2 × 107 molecules could be displayed per cell. As cells overproducing CWBMLytE and its fusions formed filamentous cells (with an average of nine individual cells per filamentous cell), 1.1 × 108β-lactamase molecules could be displayed per filamentous cell. Overproduced CWBMLytE and its fusions were distributed on the entire cell surface. Surface exposure and accessibility of these proteins were confirmed by immunofluorescence microscopy. [ABSTRACT FROM AUTHOR]