The number of patients with severe invasive group-G streptococcal (Streptococcus dysgalactiae subsp. equisimilis) infections has been increasing in Japan. The emm genotypes and SmaI-digested pulsed-field gel electrophoresis DNA profiles were variable among the strains isolated, suggesting there has not been clonal expansion of a specific subpopulation of strains. However, all strains carried scpA, ska, slo and sag genes, some of which may be involved in the pathogenesis of the disease.

To clarify the relationship between the epidemics of severe invasive group A streptococcal infections (streptococcal Toxic Shock-Like Syndrome: TSLS) and common group A streptococcal infections in Japan, we examined the T serotypes of S. pyogenes strains (group A streptococci) isolated from clinical specimens of the streptococcal infections (17999 cases) in the period 1990-5, including the severe infections (TSLS) (29 cases) in the period 1992-5. Characteristic points of the analyses were: (1) dominant serotypes of the infections in these periods were T12, T4, T1, T28 and TB3264, which were consistently isolated; (2) isolates of T3 rapidly increased through 1990 to 1994 while T6 decreased in the period 1990-3; (3) when Japanese area was divided into three parts, T3 serotype tended to spread out from the north-eastern to the south-western area; (4) strains of T3 and T1 serotypes were dominant in the TSLS. Dominant-serotype strains of streptococcal infections did not always induce severe infections and dominance of T3 serotype in the TSLS seemed to be correlated with the increase of T3 in streptococcal infections. These results may indicate that certain clones of S. pyogenes are involved in the pathogenesis of the TSLS.

We surveyed T serotypes and emm genotypes of Streptococcus pyogenes isolates from streptococcal toxic shock-like syndrome (TSLS) patients. T1 (emm1) remained dominant through 1992 to 2000, but the dominant T3 (emm3.1) strains from 1992 to 1995 disappeared during 1996-2000. Strains of several emm genotypes emerged during 1996-2000, indicating alterations in the prevalent strains causing TSLS.Streptococcus pyogenes (group A streptococcus) is one of the most common human pathogens. It causes a wide array of infections, the most frequent of which is acute pharyngitis (strep throat). Many streptococcal virulence factors involved in these symptoms have been reported, including pyrogenic exotoxins (SpeA, SpeB and SpeC) and M protein. M protein, which is an important virulence factor of S. pyogenes, protects S. pyogenes from phagocytosis by polymorphonuclear leukocytes [1,2]. More than 90 of M protein serotypes have been identified, and a molecular approach to identification of emm (M protein) genes has also been documented. For example, emm1, emm2 and emm3 genes encode the M1, M2 and M3 proteins, respectively. In addition, the emm3.1 and emm22.2 belong to the emm3 and emm22 alleles, respectively (http ://www.cdc.gov/ncidod/biotech/strep/ emmtypes.html).T serotypes of S. pyogenes have also been important markers in the epidemiological investigation of S. pyogenes infections and more than 25 different T serotypes have been described [3,4]. The combination of T serotype and emm genotype allows the identification of strain diversity [5].From the late 1980s, streptococcal TSLS caused by S. pyogenes became a serious problem in both

Background Pneumocystis jirovecii pneumonia (PCP)-related risk factors among patients with solid tumors are not completely defined. Thus, we aimed to characterize PCP cases with underlying solid tumors, to highlight the factors contributing to its development besides the prolonged use of moderate-to-high dose corticosteroids. Methods We retrospectively reviewed the medical records of patients with solid tumors diagnosed with PCP between 2006 and 2018 at a cancer center in Tokyo, Japan. Demographic and clinical data were collected, which included malignancy types, total lymphocyte count, coexisting pulmonary disease, chemotherapy, radiation therapy, corticosteroid use, and PCP-attributable mortality. Results Twenty cases of PCP with solid tumors were documented in 151,718 patients and 788,914 patient-years. Lung cancer (n = 6, 30%) was the most common underlying tumor, followed by breast cancer (n = 3, 15%). Only six (30%) patients were taking a dosage of ≥20 mg prednisone equivalents daily for ≥4 weeks from the onset of PCP. Among the remaining 14 patients, seven (50%) had coexisting pulmonary diseases, 10 (71%) had received chemotherapy within 90 days prior to PCP diagnosis, seven (50%) had undergone chest radiation therapy before PCP diagnosis, seven (50%) had received only intermittent corticosteroids, and one (7%) received no corticosteroids. Mortality attributable to PCP was 40%. Conclusions More than half of the patients were not taking a dosage of ≥20 mg prednisone equivalents daily for ≥4 weeks. Multiple other factors (e.g., lymphocytopenia, radiation to chest) may have potentially contributed to PCP in patients with solid tumors in a composite manner. We need to establish a method for estimating the likelihood of PCP taking multiple factors into account in this patient population.

Previous studies have suggested that peripheral venous catheter is a significant source of gram-negative bacteraemia in patients with malignancy. We aimed to identify risk factors and develop a clinical prediction rule for the involvement of gram-negative organisms in peripheral venous catheter-associated bloodstream infections (PVC-BSIs) among patients with malignancy. Methods This retrospective cohort study was conducted at a 700-bed cancer hospital in Japan. Consecutive patients diagnosed with PVC-BSI based on clinical and microbiological criteria were included in this study. Based on clinical and microbiological characteristics of PVC-BSIs in cancer patients, a logistic regression model for predicting gram-negative organisms as causative organisms in PVC-BSIs was then developed. Results Of the 99 patients included in our cohort, 60 patients (60.6%) had gram-negative PVC-BSIs. The median age of patients with PVC-BSIs was 67 years (interquartile range [IQR], 59-74 years), and the median Pitt bactearemia score was 1 (IQR, 0-3). The median duration of catherization was 5 days (IQR, 4-7 days) and 70 patients (70.7%) received peripheral parenteral nutrition that contained amino acids. On multivariable analysis, age �65 years (odds ratio [OR], 3.07; 95% confidence interval [CI], 1.10-8.62), showering (OR, 3.15; 95% CI,