Antiviral effect of candies containing persimmon-derived tannin against SARS-CoV-2 delta strain

Inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the mouth has the potential to reduce the spread of coronavirus disease 2019 (COVID-19) because the virus is readily transmitted by dispersed saliva. Persimmon-derived tannin has strong antioxidant and antimicrobial activity owing to its strong adhesiveness to proteins, and it also exhibited antiviral effects against non-variant and alpha variant SARS-CoV-2 in our previous study. In this report, we first demonstrated the antiviral effects of persimmon-derived tannin against the delta variant of SARS-CoV-2 in vitro via the plaque assay method. We then examined the effects of candy containing persimmon-derived tannin. Our plaque assay results show that saliva samples provided by healthy volunteers while they were eating tannin-containing candy remarkably suppressed the virus titers of the SARS-CoV-2 delta variant. In addition, we found that the SARS-CoV-2 viral load in saliva from patients with COVID-19 that was collected immediately after they had eaten the tannin-containing candy was below the level of detection by PCR for SARS-CoV-2. These data suggest that adding persimmon-derived tannin to candy and holding such candy in the mouth is an effective method by which to inactivate the SARS-CoV-2 in saliva, and the application of this approach has potential for inhibiting the transmission of COVID-19.

Transition of antibody titers after the SARS-CoV-2 mRNA vaccine in Japanese healthcare workers

Since February 2021, health care workers in Japan have been preferentially vaccinated with a messenger RNA vaccine (BNT162b2/Pfizer) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While many studies have confirmed that this vaccine is highly effective in reducing hospitalizations and deaths from coronavirus disease 2019 (COVID-19), antibody titers tend to decline at 3 months, leading to a risk of breakthrough infections. Thus, information is needed to support decision making regarding the third vaccination. In this study, we investigated transition of the anti-SARS-CoV-2 receptor-binding domain (RBD) IgG and neutralizing antibody titers of 41 vaccinated Japanese healthcare workers. Samples were collected seven times starting 1 week before vaccination until 6 months post-vaccination. Anti-SARS-CoV-2 RBD IgG levels peaked at 7 days after the booster, then declined over time and decreased to <10% at 6 months after the booster. Workers with low anti-SARS-CoV-2 RBD IgG levels also had low neutralizing antibody titers. These data support the active use of boosters for healthcare workers, especially for those with low anti-SARS-CoV-2 RBD IgG levels.

A Novel Mismatched PCR-Restriction Fragment Length Polymorphism Assay for Rapid Detection of gyrA and parC Mutations Associated With Fluoroquinolone Resistance in Acinetobacter baumannii

BACKGROUND: Mutations in the quinolone resistance-determining regions (QRDRs) of Acinetobacter baumannii DNA gyrase (gyrA) and topoisomerase IV (parC) are linked to fluoroquinolone (FQ) resistance. We developed a mismatched PCR-restriction fragment length polymorphism (RFLP) assay to detect mutations in the gyrA and parC QRDRs associated with FQ resistance in A. baumannii. METHODS: Based on the conserved sequences of A. baumannii gyrA and parC, two primer sets were designed for mismatched PCR-RFLP to detect mutations in gyrA (codons 83 and 87) and parC (codons 80 and 84) by introducing an artificial restriction enzyme cleavage site into the PCR products. This assay was evaluated using 58 A. baumannii strains and 37 other Acinetobacter strains that have been identified by RNA polymerase β-subunit gene sequence analysis.

First Two Cases of Infected Aortic Aneurysm Caused by Non-Vaccine Streptococcus pneumoniae Serotype 23A

No abstract available.

Polymicrobial Anaerobic Bacteremia Caused by Butyricimonas virosa and Brachyspira pilosicoli in a Patient with Peritonitis following Intestinal Perforation

No abstract available.

Rapid Identification of bla(IMP-1) and bla(IMP-6) by Multiplex Amplification Refractory Mutation System PCR

No abstract available.

Epidemiological Study of Erythromycin-Resistant Streptococcus pyogenes From Korea and Japan by emm Genotyping and Multilocus Sequence Typing

BACKGROUND: We determined the epidemiological characteristics of erythromycin (EM)-resistant Streptococcus pyogenes (group A streptococci, GAS) strains isolated from Korea and Japan, using emm genotyping and multilocus sequence typing (MLST). METHODS: Clinical isolates of GAS had been collected from 1992 to 2012 in Korea and from 2004 to 2009 in Japan. EM resistance was determined by the microdilution method, and resistance genotypes were assessed by PCR. The emm genotyping and MLST were performed by DNA sequencing. RESULTS: The emm genotypes and sequence types (STs) were concordant in 143 (85.1%) of 168 EM-resistant GAS strains from Korea. ST36/emm12 (35.1%), ST52/emm28 (22.6%), and ST49/emm75 (16.1%) were the most common types. Most of the ST36 (93.9%) and ST52 (95.8%) strains harbored erm(B), whereas strains ST49, ST42, and ST15 contained mef(A). The concordance between emm genotypes and STs was 41 (93.2%) among 44 EM-resistant GAS strains from Japan. ST36/emm12 (34.1%), ST49/emm75 (18.2%), and ST28/emm1 (15.9%) were the major types. ST36 isolates harbored either erm(B) (56.3%) or mef(A) (37.5%), whereas isolates ST28, ST49, and ST38 carried only mef(A). The proportion of erm(B) and mef(A) was 66.1% and 33.3% in Korea and 22.7% and 68.2% in Japan, respectively. CONCLUSIONS: The common STs in Korea and Japan were ST36 and ST49, whereas ST52 was present only in Korea and ST28 only in Japan. Genotype erm(B) was predominant in Korea, whereas mef(A) was frequent in Japan. There were differences between Korea and Japan regarding the frequencies of emm genotypes, STs, and EM resistance genes among the EM-resistant GAS.

Why do antimicrobial agents become ineffectual?

Antibiotic resistance has evolved over the past 50 years from a merely microbiological curiosity to a serious medical problem in hospitals all over the world. Resistance has been reported in almost all species of gram-positive and -negative bacteria to various classes of antibiotics including recently developed ones. Bacteria acquire resistance by reducing permeability and intracellular accumulation, by alteration of targets of antibiotic action, and by enzymatic modification of antibiotics. Inappropriate use of an antibiotic selects resistant strains much more frequently. Once resistant bacteria has emerged, the resistance can be transferred to other bacteria by various mechanisms, resulting in multiresistant strains. MRSA is one of the typical multiresistant nosocomial pathogens. A study of the PFGE pattern of endonuclease-digested chromosomal DNA showed that MRSA of a few clones were disseminated among newborns in the NICU of a Japanese hospital. In this regard, it is important to choose appropriate antibiotics and then after some time, to change to other classes to reduce the selection of resistant strains. Since the development of epoch-making new antibiotics is not expected in the near future, it has become very important to use existing antibiotics prudently based on mechanisms of antibiotic action and bacterial resistance. Control of nosocomial infection is also very important to reduce further spread of resistant bacteria.