Microbiology and Immunology

Wed, 09/23/2020 - 22:08
Brucellosis is a major zoonotic disease, and Brucella melitensis is the species most often associated with human infection. Vaccination is the most efficient tool for controlling animal brucellosis, with a consequent decrease of incidence of human infections. Commercially available live attenuated vaccines provide some degree of protection but retain residual pathogenicity to human and animals....
Wed, 09/16/2020 - 22:08
An important toxin‐antitoxin (TA) system hok/sok, encoded by R1 plasmid of Escherichia coli, is involved in post segregation killing of cells that have lost the plasmid. The lethal properties of hok protein have been utilized for the environmental containment of microbes and the development of potential vaccine candidates. We aim to demonstrate the potent anti‐microbial property of 19 amino acid...
Thu, 09/10/2020 - 22:08
Hepatitis C is a liver disease caused by the hepatitis C virus (HCV). The treatment of HCV infection has become more complicated due to various genotypes and subtypes of HCV. Treatment of HCV has made significant advances with direct‐acting antivirals. However, for the choice of medicine or the combination of drugs for hepatitis C, it is imperative to detect and discriminate the crucial HCV...
Thu, 09/10/2020 - 22:08
Shiga‐toxigenic Escherichia coli (STEC) is a major bacterium responsible for disease resulting from foodborne infection, including bloody diarrhea and hemolytic uremic syndrome (HUS). STEC produces important virulence factors such as Shiga toxin (Stx) 1 and/or 2. In the STEC family, some Locus for Enterocyte Effacement (LEE)‐negative STEC produce two different types of cytotoxins, Stx2 and...
Mon, 08/17/2020 - 22:08
Salmonella enterica serovar Typhimurium (S. Typhimurium, STM) is a leading cause of non‐typhoidal salmonellosis (NTS) worldwide. The pathogenesis of NTS has been studied extensively using a streptomycin‐pretreated mouse colitis model with the limited numbers of laboratory S. Typhimurium strains. However, the pathogenicity of the clinically isolated S. Typhimurium (STMC) strains endemic in...
Thu, 08/13/2020 - 22:08
Antigen‐specific CD8+ T‐lymphocytes (cytotoxic T‐lymphocytes: CTL), as well as CD4+ T‐lymphocytes (helper T‐lymphocytes: Th), simultaneously play an important role in elimination of intracellular bacteria such as Mycobacterium tuberculosis and Listeria monocytogenes. Administration of T‐cell epitope short peptide needs large numbers of peptides for effective vaccination due to its easily...
Fri, 08/07/2020 - 22:08
To clarify the persistence of extended‐spectrum β‐lactamase (ESBL) producers, 13 plasmids from two broiler farms were analyzed. On the farm not using antimicrobials, one plasmid from Klebsiella pneumoniae isolated from a day‐old chick was similar to that from Escherichia coli isolated a year later, with the deletion of two transposons. On the farm using antimicrobials, most circulating plasmids (...
Thu, 08/06/2020 - 22:08
The use of non‐human animal models for infection experiments is important for investigating the infectious processes of human pathogenic bacteria at the molecular level. Mammals, such as mice and rabbits, are also utilized as animal infection models, but large numbers of animals are needed for these experiments, which is costly, and fraught with ethical issues. Various non‐mammalian animal...
Wed, 07/01/2020 - 22:07
Vibrio vulnificus is a foodborne pathogen causing septicemia with high mortality rate. In this study, we explored how Escherichia coli, one of the commensal bacteria in human gastrointestinal tract, can interact with V. vulnificus. Our study showed that, the amount of biofilm produced by V. vulnificus was reduced in the presence of E. coli ATCC 35218, although the growth of V. vulnificus L‐180...
Sun, 04/19/2020 - 03:21
Botulinum neurotoxin (BoNT) is the causative agent of botulism in humans and animals. Only BoNT serotype A subtype 1 (BoNT/A1) is clinically used because of its high potency and long duration of action. BoNT/A1 and BoNT/A subtype 2 (BoNT/A2) have high degree of amino acid sequence similarity in light chain (LC) (96%), whereas their N‐and C‐terminal heavy chain (HN and HC) differ by 13%. LC acts...
Thu, 04/02/2020 - 03:15
TOLL‐interacting protein (Tollip) is a critical regulator of TLRs (toll‐like receptors) signaling pathway. It is predominantly associated with TLR2 and TLR4 during the acute inflammatory conditions and inhibits the TLR‐mediated NF‐κB activation by suppressing the auto‐phosphorylation of interleukin‐1 receptor associated kinase (IRAK1) and its kinase activity. This article describes about the...
Tue, 03/31/2020 - 03:17
ABSTRACTS Non‐O1/non‐O139 nontoxigenic Vibrio cholerae associated with cholera‐like diarrhea has been reported in Kolkata, India. However, the property involved in the pathogenicity of these strains has remained unclear. We examined the character of 25 non‐O1/non‐O139 nontoxigenic V. cholerae isolated during 8 years from 2007 to 2014 in Kolkata. Determination of serogroup showed that the...
Mon, 03/23/2020 - 03:18
Papillomatous digital dermatitis (PDD) is a foot disease causing lameness in dairy cattle. It is regarded as a polymicrobial infection, although its etiology is not fully understood. PDD is treated by the topical or systemic administration of antibiotics such as lincomycin (LCM); however, the milk of the cows cannot be marketed during the treatment and withdrawal period due to the residual...
Wed, 02/19/2020 - 03:19
In the 1980s, I found that the chromosomal β‐lactamase of Klebsiella pneumoniae LEN‐1 showed a very high similarity to the R‐plasmid‐mediated penicillinase TEM‐1 on amino acid sequence level, and this strongly suggested the TEM‐1 originated from the chromosomal penicillinases of K. pneumoniae or related bacteria. Moreover, the chromosomal K1 β‐lactamase (KOXY) of Klebsiella oxytoca was found to...
Fri, 02/14/2020 - 03:15
ABSTRACT Hepatitis A Virus (HAV) has begun to spread globally among men who have sex with men (MSM). Hepatitis E Virus (HEV) also may be transmitted through sexual contact among MSM. To assess the current status of these viruses among MSM in Japan, the seroprevalence of both viruses using 503 plasma samples collected between 2009 and 2018 from HIV‐positive male donors who were presumed to be...
Wed, 01/15/2020 - 03:15
Avian influenza viruses (AIVs) recognize sialic acid linked α2,3 to galactose (SAα2,3Gal) glycans as receptors. In this study, the interactions between hemagglutinins (HAs) of AIVs and sulfated SAα2,3Gal glycans were analyzed in order to clarify the molecular basis of interspecies transmission of AIVs from ducks to chickens. It was revealed that E190V and N192D substitutions of the HA increased...
Fri, 12/20/2019 - 03:16
Vibrio parahaemolyticus is a leading cause of seafood‐borne bacterial gastroenteritis in humans. Since its discovery in 1950, this bacterium has been isolated in widespread outbreaks and in sporadic cases of gastroenteritis worldwide. Although the exotoxin, thermostable direct hemolysin (TDH), had been the focus of extensive research on the pathogenicity of V. parahaemolyticus, the whole‐genome...
Thu, 12/12/2019 - 03:17
Multidrug efflux pumps play an important role in bacterial multidrug resistance by actively excreting antibiotics. The ABC‐type drug efflux pump MacAB was originally recorded as a macrolide‐specific pump. MacAB is also known to be required for the virulence of Salmonella enterica serovar Typhimurium following oral infection in mice. Here, we performed a screening of inhibitors of Salmonella MacAB...
Fri, 10/11/2019 - 03:19
ABSTRACT We conducted a serological survey to detect antibodies against influenza A virus (IAV) in Japanese wild boars in Kagoshima prefecture, Japan, between 2014 and 2017. Sero‐prevalence against a pandemic‐like swine H1N1 (H1N1pdm) virus was identified in 27.1% of specimens, and 1.7% were positive for both swine H1N2 and H3N2 viruses, indicating that wild boars could play an important role in...
Mon, 09/23/2019 - 03:15
Kenya is endemic for cholera with different waves of outbreaks having been documented since 1971. In recent years, new variants of Vibrio cholerae O1 have emerged and have replaced most of the traditional El Tor biotype globally. These strains also appear to have increased virulence, and it is important to describe and document their phenotypic and genotypic traits. This study characterized 146 V...