Study of post-opening stability of active ingredients in hand sanitizers.

INTRODUCTION: Hand disinfection plays an important role in infection control. Currently, hand sanitizers containing ethanol and chlorhexidine gluconate as active ingredients are widely used. Most of hand sanitizers have a defined expiration date for use. However, there was no rule about the expiration date after opening defined with the evidence. Therefore, we examined the fluctuation of active ingredients and disinfection effect after opening the bottle. METHOD: Twelve hand sanitizers from 44 to 921 days after opening set in different places in the hospital were examined and unopened hand sanitizer used as a control. Chlorhexidine gluconate and ethanol of each samples were measured by high performance liquid chromatography and gas chromatography, respectively. The correlation between the concentration of each ingredient obtained and the number of days after opening, bottle weight, storage temperature and humidity was analyzed. A time-kill test based on ASTM E2315-03 was performed to confirm the actual disinfection effect. RESULTS: It was observed that active ingredients had not been decreased up to 921 days after opening and were not affected by storage conditions after opening. In addition, a decrease of disinfection effect was not observed in any sample. CONCLUSIONS: We found that hand sanitizers do not need to be discard after a number of days have passed because the active ingredients are retained even after opening in it.

Clonality investigation of clinical Escherichia coli isolates by polymerase chain reaction-based open-reading frame typing method.

Escherichia coli (E. coli) causes urinary tract infections, pneumonia, surgical site infections, and bloodstream infections and is the important pathogen for both community-acquired and healthcare-associated infections. To investigate the clonality of E. coli is important for infection control and prevention. We aimed to investigate the clonality of clinical E. coli isolates using Cica Geneus E. coli polymerase chain reaction (PCR)-based open-reading frame typing (POT) KIT and clarify the clinical usefulness of this kit. About 124 E. coli isolates obtained from inpatients at Sapporo Medical University Hospital were used. The POT method was used to classify 124 clinical isolates into 87 POT numbers. In addition to the clonality, it was possible to obtain additional information that 20 of the 124 isolates were extended-spectrum ß-lactamase (ESBL) producing E. coli (5 isolates of CTX-M-1 group and 15 isolates of CTX-M-9 group) and 13 were sequence type (ST) 131 clone. Furthermore, when these ESBL-producing 20 isolates were compared with pulsed-field gel electrophoresis (PFGE) or multilocus sequence typing (MLST), Simpson's index of diversity was 0.968 in POT method, 0.979 in PFGE, and 0.584 in MLST. POT method had an analytical power similar to that of PFGE. In conclusion, attention should be paid to the difference in the interpretation of the results between the POT method and the PFGE, but POT method may be useful to timely monitor the spread of E. coli in medical facilities.

[Four Cases of Bacteremia Caused by Helicobacter cinaedi in the Urological Ward at About the Same Time].

Here we report the outbreak of bacteremia caused by Helicobacter cinaedi (H. cinaedi) in the urology ward. Case 1 was a man in his seventies with prostate cancer. Bacteremia caused by H. cinaedi developed 6 days after robot-assisted radical prostatectomy. Case 2 was a man in his sixties with small cell carcinoma of the prostate. Bacteremia developed at 5 days of docetaxel therapy. Case 3 was a man in his fifties with left renal pelvis carcinoma. Bacteremia developed 3 days after laparoscopic left nephroureterectomy. Case 4 was a man in his seventies with right renal pelvic carcinoma and bladder cancer. Bacteremia developed 22 days after laparoscopic right nephroureterectomy and laparoscopic radical cystectomy. Each bacteremia occurred almost simultaneously. Fortunately, all 4 cases were treated by antibiotics successfully and there were no cases of recurrence. Whole environmental inspection of the ward did not reveal H. cinaedi. However, multilocus sequence typing proved the strains in cases 3 and 4 to be the same. Therefore, cross-infection was suspected. H. cinaedi can develop to a pathogen of immunocompromised infection. This report clarified that this pathogen can cause bacteremia in the urology ward.

Pseudo-outbreak of Mycobacterium lentiflavum at a general hospital in Japan.

BACKGROUND: Mycobacterium lentiflavum is a slow-growing nontuberculous mycobacterium that is widely distributed in soil and water systems, but it is sometimes pathogenic to humans. Although cases of M. lentiflavum infections are rare, 22 isolates of M. lentiflavum were identified at a single hospital in Japan. We suspected a nosocomial outbreak; thus, we conducted transmission pattern and genotype analyses. METHODS: Cases of M. lentiflavum isolated at Kushiro City General Hospital in Japan between May 2020 and April 2021 were analyzed. The patient samples and environmental culture specimens underwent whole-genome sequencing (WGS). Additionally, we retrospectively collected clinical data from patient medical records. RESULTS: Altogether, 22 isolates of M. lentiflavum were identified from sputum and bronchoalveolar lavage samples. Clinically, the instances with M. lentiflavum isolates were considered contaminants. In the WGS analysis, 19 specimens, including 18 patient samples and 1 environmental culture from the hospital's faucet, showed genetic similarity. The frequency of M. lentiflavum isolation decreased after we prohibited the use of taps where M. lentiflavum was isolated. CONCLUSIONS: WGS analysis identified that the cause of M. lentiflavum pseudo-outbreak was the water used for patient examinations, including bronchoscopy.

Genotypes and transmission routes of noroviruses causing sporadic acute gastroenteritis among adults and children, Japan, 2015-2019.

Noroviruses (NoVs) are major causes of acute viral gastroenteritis at all ages worldwide. The molecular epidemiology of sporadic cases remains poorly understood, especially in adults. Additionally, no studies have analyzed the transmission route in sporadic acute gastroenteritis. In this study, we investigated cases of very mild sporadic NoV acute gastroenteritis in adults (medical staff) who do not visit the outpatient clinic and child outpatients. We also evaluated genotype differences between adults and children and possible transmission routes in adults during 5 years. The number of NoV positives were 58 in adults and 124 in children. In adults, the NoV positivity rate in this study was higher (64.4%) than that in previous reports of outpatients (10%) and inpatients (5%) in the United State. This finding suggested that the NoV positivity rate might be high in adults with very mild acute gastroenteritis. In adults, human-to-human transmission rates from children and food-borne transmission (raw oysters) were 21.6% (11/51) and 19.6% (10/51), respectively. Among adults, GII.2, GII.4, and GII.17 were the predominant genotypes, with rates of 32.7%, 30.9%, and 21.8%, respectively. Among children, GII.4 and GII.2 were the predominant genotypes, with rates of 45.5% and 40.6%, respectively. GII.17 was only detected in 0.8% (1/123) of children. Trends in NoV genotypes are expected to differ depending on the patient's age. Investigating sporadic cases including the patient's background (age and transmission route) may be helpful to monitor the trend of NoV strains, forecast prevalent NoV GII genotypes, and develop NoV vaccines.