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.

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.

Aldose reductase gene is associated with diabetic macroangiopathy in Japanese Type 2 diabetic patients

AIMS

The aldose reductase (AR) gene, a rate-limiting enzyme of the polyol pathway, has been investigated as a candidate gene in determining susceptibility to diabetic microangiopathy. However, the association of the AR gene with diabetic macroangiopathy has not been investigated. Therefore, the present study was conducted to determine whether genetic variations of AR may determine susceptibility to diabetic macroangiopathy.

METHODS

There were 378 Type 2 diabetic patients enrolled in this study. A single nucleotide polymorphism in the promoter region (C-106T) was genotyped and the AR protein content of erythrocytes measured by ELISA.

RESULTS

There were no significant differences in genotypic or allelic distribution in patients with or without ischaemic heart diseases, but there was a significant increase in the frequency of the CT + TT genotype and T allele in patients with stroke (P = 0.019 and P = 0.012). The erythrocyte AR protein content was increased in patients with the CT and TT genotype compared with those with the CC genotype. After adjustment for age, duration of diabetes, body mass index, systolic blood pressure, HbA1c, and serum creatinine, triglycerides, and total cholesterol in multivariate logistic-regression models, the association between this AR genotype and stroke remained significant.

CONCLUSIONS

Our results suggest that the CT or TT genotype of the AR gene might be a genetic marker of susceptibility to stroke in Type 2 diabetic patients. This observation might contribute to the development of strategies for the prevention of stroke in Type 2 diabetic patients.

Human proinsulin C-peptide prevents proliferation of rat aortic smooth muscle cells cultured in high-glucose conditions

AIMS/HYPOTHESIS

Proinsulin C-peptide is involved in several biological activities. However, the role of C-peptide in vascular smooth muscle cells is unclear. We therefore investigated its effects, in vascular smooth muscle cells in high-glucose conditions.

METHODS

Rat aortic smooth muscle cells were cultured with 5.5 or 20 mmol/l glucose with or without C-peptide (1 to 100 nmol/l) for 3 weeks. Proliferation activities, the protein expression of platelet-derived growth factor (PDGF)-beta receptor, the phosphorylation of p42/p44 mitogen-activated protein (MAP) kinases, and glucose uptake were measured.

RESULTS

The proliferation activities increased approximately three-fold under high-glucose conditions (p<0.05). C-peptide suppressed hyperproliferation activities that were induced by high glucose. This happened in a dose-dependent manner from 1 to 100 nmol/l of C-peptide. C-peptide (10 and 100 nmol/l) inhibited the increased protein expression of PDGF-beta receptor and the phosphorylation of p42/p44 MAP kinases that had been induced by high glucose (p<0.05). Furthermore, 100 nmol/l of C-peptide augmented the impaired glucose uptake in the high-glucose conditions.

CONCLUSIONS/INTERPRETATION

These observations suggest that C-peptide could prevent diabetic macroangiopathy by inhibiting smooth muscle cell growth and ameliorating glucose utilisation in smooth muscle cells. C-peptide may thus be a novel agent for treating diabetic macroangiopathy in patients with type 1 and type 2 diabetes.

Relationship of androgens to muscle size and bone mineral density in women with polycystic ovary syndrome

OBJECTIVE

To investigate the relationship of androgens to regional muscle size and bone mineral density (BMD) in women with polycystic ovary syndrome (PCOS).

METHODS

Seventy-one amenorrheic and right-side dominant women with PCOS (mean age +/- standard deviation 28.1 +/- 6.7 years) were enrolled. Baseline characteristics included age, height, weight, and body mass index (BMI). Regional BMD and lean mass were measured by whole-body scanning with dual-energy x-ray absorptiometry. Serum levels of testosterone, dehydroepiandrosterone sulfate (DHEAS), and androstenedione were measured by radioimmunoassay. Correlations between regional BMD and variables were investigated using a Pearson correlation test and multiple regression analysis.

RESULTS

Serum testosterone levels correlated significantly with lean mass of the left arm, right arm, trunk, left leg, and right leg (r =.34, P <.05 to r =.50, P <.01). Regional lean mass correlated significantly with respective regional BMD (r =.30, P <.05 to r =.68, P <.001). These relationships remained significant after adjusting for age, height, and weight. Serum testosterone levels were not correlated with BMD of the bilateral arms and lumbar spine. Although serum testosterone levels correlated with leg BMD (r =.34, P <.05 to r =.45, P <.01), significance did not persist after adjusting for respective regional lean mass.

CONCLUSION

Testosterone influences regional BMD through increasing regional muscle mass in women with polycystic ovary syndrome.

Waist to hip circumference ratio as a significant predictor of preeclampsia, irrespective of overall adiposity

OBJECTIVE

To investigate whether abnormal body fat distribution is a significant predictor of the development of preeclampsia, irrespective of overall adiposity.

METHODS

Twenty-six women with preeclampsia and 198 control women were enrolled. Waist to hip circumference ratio (WHR), body weight (BW), and body mass index (BMI, wt/ht2) were measured early in pregnancy (< 9 weeks of gestational age). Age, height, parity, tobacco usage, education period, gestational duration, and weight gain during pregnancy were also recorded for each subject.

RESULTS

WHR, BMI, and BW early in pregnancy were significantly higher in the preeclampsia group (p < 0.0001). WHR, BMI, and BW positively correlated with the development of preeclampsia on univariate regression analysis (Standardized regression coefficient = 0.410, 0.387, and 0.363, respectively, p < 0.0001). On stepwise multiple regression analysis, WHR still correlated with the development of preeclampsia irrespective of BMI and BW. When the WHR predictive of the development of preeclampsia was set at 0.9, the sensitivity was 46.2% (12/26), which was significantly better than that of 25 of BMI (19.2%, 5/26; p < 0.05).

CONCLUSION

Higher WHR is a significant predictor of the development of preeclampsia. This relation is irrespective of overall adiposity.

[Epidemiological studies on drug-resistance patterns, coagulase types, and MRSA-phage types of MRSA isolates during 1990-1994]

We examined drug-resistance patterns, coagulase types, and MRSA-phage types of 125 MRSA strains isolated from clinical specimens during the period of January 1990 and December 1994. No vancomycin-resistant strain was isolated. Twenty one antibiotics were divided into three classes, low-intermediate- and high-isolation-frequency class, based on isolation frequencies of resistant strains. Minocycline, chloramphenicol, streptomycin, and imipenem were found to be included in low-isolation-frequency class (16.8-40%). In intermediate-isolation-frequency class (45.6-62.9%), cefmetazole, amikacin, gentamicin, and tetracycline were included. Oxacillin, ampicillin, piperacillin, ceftizoxime, cefoperazone, cefazolin, erythromycin, oleandomycin, kitasamycin, clindamycin, kanamycin, tobramycin, and ofloxacin belonged to high-isolation-frequency class (97.6-100%). MIC90s of vancomycin and minocycline (1.56 and 25 micrograms/ml) were lower than that of other 13 drugs. Comparing medical ward with dental ward, imipenem-, gentamicin-, and minocycline-resistant strains at medical ward, chloramphenicol- and streptomycin-resistant strains at dental ward were isolated dominantly on each ward, MRSA isolates were classified to 39 types by drug-resistance patterns. The isolation frequencies of coagulase type II and type IV strains were 65.6% and 29.6%, respectively. At dental ward, the isolation frequency of coagulase type IV strains was higher than that of coagulase type II strains during 1990-1992. However, coagulase type II strains were isolated considerably more than type IV strains during 1993-1994. By MRSA-phage typing, MRSA isolates were grouped into 18 MRSA-phage types. One hundred and twenty five MRSA isolates were divided into 56 types by using drug-resistance patterns, coagulase typing, and MRSA-phage typing. It was considered that such classification in combination of three methods is useful to make decision of epidemic by the same MRSA strain.

[Drug susceptibility of clinically isolated Helicobacter pylori]

Between January 1995 and March 1997, 78 Helicobacter pylori strains were isolated from patients with gastritis and gastric ulcer and their drug-susceptibilities to 8 antimicrobial agents and 3 anti-ulcer drugs were determined. Imipenem was the most active agent and its MICs to all the strains tested were lower than 0.013 microgram/ml. Amoxicillin, cefaclor and minocycline were active against H. pylori with MIC90s of 0.05 microgram/ml, 0.78 microgram/ml and 0.39 microgram/ml, respectively, and no resistant strains against these drugs were isolated. However, resistant strains to clarithromycin (isolation frequency: 9%), erythromycin (13%), ofloxacin (8%) and metronidazole (13%) were isolated. Triple, double and single resistant strains to above 4 antimicrobial agents were noted. No quadruple resistant strain was isolated. Frequencies of those resistance patterns were 14.3% (triple), 28.6% (double), and 57.1% (single), respectively. Seven erythromycin-resistant strains were shown to be cross-resistant to clarithromycin but 3 erythromycin-resistant strains were susceptible to clarithromycin. It seems likely that this phenomenon is caused by the fact that clarithromycin is more active to H. pylori than erythromycin. The MIC90 value of lansoprazole was lower than those of omeprazole and famotidine.

[Serotypes and drug susceptibility of Pseudomonas aeruginosa isolated from clinical specimens]

Between January, 1982 and December, 1994, 236 Pseudomonas aeruginosa strains were isolated from clinical specimens at our division, and were tested for serotypes and drug-susceptibilities to 15 antibiotics. Serotype G strains were isolated at the highest frequency (32.6%), and followed by strains of serotype B (15.7%), A (11.9%), E (9.3%), I (7.2%), F and M (5.5%), non-typable (5.1%), D (3.4%), H (2.1%), C and K (0.8%). We examined the changes of isolation frequencies of different serotypes annually. Isolation frequencies of serotypes E and F showed tendency to decrease, whereas serotype I has been isolated increasingly year by year. MIC90's of the 15 antibiotics were as follows, tosufloxacin: 0.78 microgram/ml, biapenem (BIPM) and ofloxacin (OFLX): 3.13 micrograms/ml, imipenem (IPM), ceftazidime, cefozopran, cefsulodin and gentamicin: 6.25 micrograms/ml, aztreonam and amikacin: 12.5 micrograms/ml, piperacillin, cefoperazone and minocycline (MINO): 25 micrograms/ml, fosfomycin: > 100 micrograms/ml and chloramphenicol: > 200 micrograms/ml. MIC90'S of IPM, BIPM, MINO and OFLX increased 4-fold from stage I (1982-1987) through stage III (1992-1994) and the isolation frequency of drug-resistant strains increased year by year. In other words, antibiotic resistant strains appeared increasing with time. No relationship between serotypes and drug-resistance were observed.

Presence of beta-citryl-L-glutamic acid in the lens: its possible role in the differentiation of lens epithelial cells into fiber cells

The beta-CG concentration in the chicken brain was high during embryonic development and decreased rapidly to a lower level close to hatching, while the concentration in the eyeball which was also high during the embryonic life retained a fairly high level after hatching. The distribution of beta-CG in the bovine eye was determined. About 95% of total beta-CG content in the whole eye was localized in the lens. However, the distribution of beta-CG in the eye varied depending on species. beta-CG was exclusively localized in the lens in the eyes of fish and mammals, but distributed in both lens and retina in frogs. The molecule was localized in the retina rather than the lens in the chicken eye, although the concentrations was extremely low compared to those in the mammalian, amphibian and fish eyes. It was found that beta-CG is present ubiquitously in the lens or retina in various species. The distribution of beta-CG in the bovine lens was determined in the three cortex regions and nucleus. beta-CG was present at the highest concentration in the equatorial cortex, at a moderate concentration in the posterior and anterior cortex, and at the lowest concentration in the nucleus. Similar distribution patterns were also found in the rabbit and rat lens. When embryonic chick lens epithelial cells were cultured in the presence of fetal calf serum, the cells elongated, differentiated into fiber cells and formed lentoid bodies. The cells of lentoid bodies were stained strongly by the anti-beta-CG antibody, while cells around the structures were not. In addition, the beta-CG content in the lenses from the galactose cataractous rat decreased to about 20-30% of that in the normal lens. These findings suggest that beta-CG may play a role in the differentiation of epithelial cells into fiber cells.

[Two cases of diffuse panbronchiolitis receiving long-term erythromycin (EM) therapy with acute exacerbation due to EM-resistant pneumococcus]

The first case was a 73-year-old woman with chief complaints of fever, cough, purulent sputum and dyspnea. EM therapy was begun in December 1983 due to a diagnosis of diffuse panbronchiolitis (DPB). Subsequently, P. aeruginosa was persistently detected, while in February 1991 at the time of an acute exacerbation of the DPB P. aeruginosa and S. pneumoniae were detected by TTA. The second case was a 65-year-old man with chief complaints of fever, cough and purulent sputum. DPB was diagnosed and EM therapy was begun in December 1985. In January 1991, pneumonia developed, at the time when S. pneumoniae was detected by TTA. In both cases, rapid disappearance of S. pneumoniae from the sputum and alleviation of symptoms were obtained with carbapenem antibiotic administration. Both strains were resistant to EM, Tetracycline (TC), Minocycline (MINO) and Clindamycin (CLDM). Particularly, S. pneumoniae of case 2 showed low sensitivity to Ampicillin (ABPC), Cefotiam (CTM) and Cefoxitin (CFX) as well. These cases showed acute exacerbations due to EM-resistant pneumococcus during long-term therapy with EM, and are of interest in that they may shed light on the relation between long-term EM therapy and the emergence of resistant pneumococcus.

Pantoea punctata sp. nov., Pantoea citrea sp. nov., and Pantoea terrea sp. nov. isolated from fruit and soil samples

A total of 37 bacterial strains with the general characteristics of the family Enterobacteriaceae were isolated from fruit and soil samples in Japan as producers of 2,5-diketo-D-gluconic acid from D-glucose. These organisms were phenotypically most closely related to the genus Pantoea (F. Gavini, J. Mergaert, A. Beji, C. Mielearek, D. Izard, K. Kersters, and J. De Ley, Int. J. Syst. Bacteriol. 39:337-345, 1989) and were divided into three phenotypic groups. We selected nine representative strains from the three groups for an examination of DNA relatedness, as determined by the S1 nuclease method at 60 degrees C. Strain SHS 2003T (T = type strain) exhibited 30 to 41 and 28 to 33% DNA relatedness to the strains belonging to the strain SHS 2006T group (strains SHS 2004, SHS 2005, SHS 2006T, and SHS 2007) and to the strains belonging to the strain SHS 2008T group (strains SHS 2008T, SHS 2009, SHS 2010, and SHS 2011), respectively. Strain SHS 2006T exhibited 38 to 46% DNA relatedness to the strains belonging to the strain SHS 2008T group. The levels of DNA relatedness within the strain SHS 2006T group and within the strain SHS 2008T group were more than 85 and 71%, respectively. Strain SHS 2003T, SHS 2006T, and SHS 2008T DNAs exhibited less than 18% binding to Pantoea dispersa ATCC 14589T and Pantoea agglomerans ATCC 27155T DNAs.(ABSTRACT TRUNCATED AT 250 WORDS)

Design of temperature-sensitive penicillinase repressors by replacement of Pro in predicted beta-turn structures

Pro residues in predicted beta-turn structures were substituted with other amino acids to obtain temperature-sensitive penicillinase repressors (PenI). A mutant repressor (P70L; Pro-70 is substituted with Leu) was inactive at 48 degrees C and penP gene expression was derepressed (1,200 U/OD660 [optical density at 660 nm] ), although the mutant was still active at 30 degrees C (27 U). The heat induction ratio (penicillinase activity at 48 degrees C compared with that at 30 degrees C) of the mutant was 98 times higher than that of the wild type (i.e., 44 versus 0.45). This result indicated that the side chain of the Leu residue in P70L destroyed the proper folding of the repressor protein at the elevated temperature, whereas the Pro residue of the wild-type repressor stabilized this predicted beta-turn structure even at 48 degrees C. When the Pro residue was replaced by amino acid residues with smaller side chains (i.e., Gly and Ala), these mutant repressors were less temperature sensitive than P70L. These data suggest that the presence of the Pro residue in the beta-turn structure could be one of the key factors in stabilizing protein structure at elevated temperatures.

Drug resistance in Streptococcus pyogenes isolated in Japan

Drug resistance of Streptococcus pyogenes strains isolated during 1974 and 1975 in various districts in Japan were surveyed and compared with an earlier survey of 1970 to 1973. Of 1,021 strains, tetracycline-, macrolide antibiotic-, lincomycin-, and chloramphenicol-resistant strains were demonstrated at frequencies of 80.3, 62.3, 60.8, and 57.9%, respectively. Distinct group resistances to penicillin and aminoglycoside antibiotics could not be identified among the strains examined. It was characteristic that quadruple and triple resistances were manifested among the strains resistant to macrolide antibiotics, lincomycin, tetracycline, and chloramphenicol, and they were confined to the T-type 12. The emergence of multiply resistant streptococcal strains was due mostly to the rapid increase in isolation frequency of macrolide antibiotic- or macrolide antibiotics-lincomycin-resistant strains.

Artificial elimination of drug resistance from group A beta-hemolytic streptococci

Ten strains of beta-hemolytic streptococci were tested for elimination of resistance to macrolide antibiotics, tetracycline, and chloramphenicol. Six of the strains lost resistance after cultivation at 41 C or addition of acriflavine (0.2 mug/ml). These results suggest that determinants governing resistance to these antibiotics are located on extrachromosomal genetic elements (plasmids) that are widely distributed in streptococci.

In vitro and in vivo activity of penicillinase inhibitor KA-107 against Staphylococcus aureus FS-1277

The activities of penicillinase inhibitor, KA-107 extracted from culture filtrates of Streptomyces gedanensis ATCC 4880, were studied by using penicillin-resistant S. aureus FS-1277 and by means of in vitro and in vivo tests.