Isolation and characterization of Staphylococcus argenteus strains from retail foods and slaughterhouses in Japan.

Staphylococcus argenteus has been recently established as a novel species of Staphylococcus aureus complex. It is known to cause various human diseases, such as skin and soft-tissue infections, sepsis, and staphylococcal food poisoning, although the source of infection has not been clearly described. In food poisoning cases, the source of bacterial contamination in food is unknown. This study examined the prevalence of S. argenteus among retail fresh food and poultry slaughterhouses in Japan. Among 642 food samples examined, successful isolation of S. argenteus was achieved in 21 of 151 (13.9%) chicken samples. No isolations from pork, beef, fish, or vegetables in retail markets were confirmed. Multiple-locus sequence typing revealed that the 21 isolates were classified into four sequence types (ST) that were divided into 14 subtypes using spa-typing. All food isolates were susceptible to methicillin and did not show positivity for the Panton-Valentine leukocidin gene. When bacteria were isolated from two poultry slaughterhouses in the same region, 14 S. argenteus strains were successfully isolated from only one slaughterhouse. Thirteen of 14 strains were isolated from a poultry carcass and slaughterhouse environments during a certain sampling period and were all classified as ST5961 with identical spa-type. Also, the number of single nucleotide variants (SNVs) detected on the core genomes of the same 13 strains were between 0 and 17, suggesting a long-term inhabitation of an S. argenteus strain inside the facility. Furthermore, one isolate from chicken meat was also genetically linked with the same lineage of slaughterhouse isolates, with ≤15 SNVs being detected. Additionally, one slaughterhouse isolate from chiller water and three chicken isolates were classified into the same cluster by phylogenetic analysis, although the number of pairwise SNVs ranged from 62 to 128. To the best of the authors' knowledge, this is the first study that demonstrated S. argenteus in a food processing facility and the possible bacterial contamination on food during food processing.

Foodborne Outbreak of Group G Streptococcal Pharyngitis in a School Dormitory in Osaka, Japan.

In September 2016, 140 patients with primary symptoms of sore throat and fever were identified in a school dormitory in Osaka, Japan. Epidemiological and laboratory investigations determined that these symptomatic conditions were from a foodborne outbreak of group G streptococcus (GGS), with GGS being isolated from samples from patients, cooks, and foods. The strain of GGS was identified as Streptococcus dysgalactiae subsp. equisimilis of two emm types (stG652.0 and stC36.0). The causative food, a broccoli salad, was contaminated with the two types of S. dysgalactiae subsp. equisimilis, totaling 1.3 × 104 CFU/g. Pulsed-field gel electrophoresis (PFGE) of samples from patients, cooks, and foods produced similar band patterns among samples with the same emm type. This result suggested the possibility of exposure from the contaminated food. The average onset time was 44.9 h and the prevalence rate was 62%. This is the first report to identify the causative food of a foodborne outbreak by Streptococcus dysgalactiae subsp. equisimilis.

Influence of amino-acid polymorphism in the core protein on progression of liver disease in patients infected with hepatitis C virus genotype 1b.

The substitution of amino acid (aa) 70 of arginine for glutamine and/or that of aa91 of leucine for methionine in the core protein in patients infected with hepatitis C virus (HCV) genotype 1b is associated with a poor response to pegylated interferon and ribavirin. Factors influencing these substitutions were sought in 1,097 patients infected with HCV-1b who had not received antiviral treatment. HCV variants with Arg70 and Leu91 (wild-type) decreased, while those with Gln70 and/or Met91 (mutant types) increased with age (P < 0.001). Of the 1,097 patients, 464 (42.3%) were infected with the Gln70 variant and the remaining 633 patients with the Arg70 variant. The proportion of patients with the Gln70 variant increased with the severity of liver disease (P < 0.001), elevated gamma-glutamyl transpeptidase (gamma-GTP) levels (P < 0.001) and a decrease in platelet count (P = 0.008). In univariate analysis patients with hepatocellular carcinoma, elevated aspartate aminotransferase (AST > or = 58 IU/L) and gamma-GTP (> or =61 IU/L), and decreased albumin levels (<3.9 g/dl) were more frequent in the patients with the Gln70 variant than the Arg70 variant (P = 0.003, 0.005, <0.001, and 0.031, respectively). In multivariate analysis HCC (odds ratio 1.829 [95% confidence interval 1.147-2.917]) and gamma-GTP > or =61 IU/L (1.647 [1.268-2.139]) increased the risk for the Gln70 variant. In conclusion, the substitution of amino aa70 of Arg for Gln in patients infected with HCV-1b increases with age, and it is associated with severe liver disease accompanied by elevated AST and gamma-GTP levels, as well as the development of hepatocellular carcinoma.

Correlation of YMDD mutation and breakthrough hepatitis with hepatitis B virus DNA and serum ALT during lamivudine treatment.

AIM: Continuous lamivudine treatment is associated with high frequency of drug resistance. We analyzed the incidence of tyrosine-methionine-aspartate-aspartate (YMDD) motif mutant and breakthrough hepatitis (BTH) in hepatitis B virus (HBV) DNA positive patients receiving lamivudine for > 1 year and correlated it with HBV DNA and alanine aminotransferase (ALT) levels to evaluate if these measurements can provide a practical option for monitoring patients in clinical practice and define early switch from lamivudine therapy. METHODS: Of the 929 patients receiving lamivudine for > 1 year, 359 patients who maintained an ALT level of /= 3 years. RESULTS: The incidence of YMDD motif in patients receiving lamivudine for < 3 years was 27% in patients with ALT

Sustained virological response in a patient with chronic hepatitis C treated by monotherapy with the NS3-4A protease inhibitor telaprevir.

Here, we describe for the first time a case of sustained virological response (SVR) achieved in a patient with chronic hepatitis C (CH-C) by monotherapy with a NS3-4A protease inhibitor, telaprevir, without interferon therapy. A 59-year-old treatment-naïve Japanese man was enrolled in a phase II trial of telaprevir by repeat oral administration at a dose of 750mg every 8h for 24 weeks. At the start of treatment, he exhibited a low-level viremia with genotype 1b of the hepatitis C virus (HCV). After the first week of treatment with telaprevir, serum HCV RNA was undetectable, and negativity remained until the end of treatment. Moreover, he was evaluated as having a SVR after the post-treatment 24-week follow-up program. Two characteristics may explain the strong antiviral activity of telaprevir in the present case. First, although pre-treatment PCR-direct sequencing and cloning for the N-terminal in the NS3 region showed a protease inhibitor-resistant variant (T54A) in 1 of 32 independent clones, the T54A substitution has only a low-level resistance to protease inhibitors and his viral load was low. Second, when compared to a consequence sequence of 35 treatment-naïve patients with HCV genotype 1b, R130K and Q195K substitutions were unique to the present case. Although it is presently unknown whether the R130K and Q195K substitutions are related to SVR, this case suggests that long-term telaprevir monotherapy may be effective in CH-C patients with genotype 1 and a low viral load.

Acute onset antenatal fetal neurological injury suspected prenatally based on abnormalities in antenatal testing: a case report.

This report discusses the case of a fetus with previously normal findings of cardiotocograph that experienced an acute neurologic insult antenatally. The fetus presented with abnormalities of its heart rate tracing and its movement patterns on ultrasound. Following delivery, the infant was diagnosed with hypoxic ischemic encephalopathy by DWI in the first 24 h after birth, despite having a normal postnatal brain ultrasound.

Rapid loss of hepatitis C virus genotype 1b from serum in patients receiving a triple treatment with telaprevir (MP-424), pegylated interferon and ribavirin for 12 weeks.

AIM: To evaluate the efficacy and safety of the triple treatment with telaprevir (MP-424), pegylated interferon (PEG-IFN) and ribavirin during 12 weeks on-treatment. METHODS: The triple treatment was given to 20 patients with chronic hepatitis C who had been infected with hepatitis C virus (HCV)-1b in high viral load (median: 6.8 log IU/mL [range: 5.5-7.2]), with a median age of 54 years (range: 36-65 years). They were followed for early dynamics of HCV RNA in serum during 12 weeks and side-effects. RESULTS: HCV RNA levels decreased by 4.8 logs by 7 days and 5.5 logs by 14 days. HCV RNA disappeared in 50% (10/20) at 2 weeks, 79% (15/19) at 4 weeks, 88% (14/16) at 6 weeks, 94% (15/16) at 8 weeks and 100% (13/13) at 12 weeks. HCV RNA disappeared equally frequently in 10 treatment-naive patients, six non-responders to IFN monotherapy and four non-responders to PEG-IFN and ribavirin. It was no different in the patients with and without amino acid substitutions reducing the response to IFN. The treatment was withdrawn in seven (35%) patients, mostly due to reduced hemoglobin of less than 8.5 g/dL, of whom six (86%) remained clear of HCV RNA at 12 weeks. CONCLUSION: HCV RNA was lost from serum rapidly and universally in patients infected with HCV-1b in high viral loads by the triple treatment. Because an early loss of HCV RNA correlates with high rates of sustained virological response (SVR), it would increase SVR substantially, and merit the patients who have not responded to previous therapies.

Development of hepatocellular carcinoma in elderly patients with chronic hepatitis C with or without elevated aspartate and alanine aminotransferase levels.

OBJECTIVE: Hepatocellular carcinoma (HCC) in the elderly infected with hepatitis C virus (HCV) is expected to increase globally within the next two decades. The purpose of the study was to define the natural history of elderly patients with chronic hepatitis C needs in order to prevent HCC from arising in these patients. MATERIAL AND METHODS: Treatment-naive patients aged >or=65 years with platelet counts >120 x 10(3)/mm(3) were classified as 120 with aspartate and alanine aminotransferase (ASAT and ALAT) levels or=41 (group B) and followed-up for 3 years or longer without antiviral treatment. RESULTS: Cirrhosis and HCC developed more frequently in group B than in group A (p<0.001 for both). In particular, of the patients aged 65-69 years at entry, cirrhosis and HCC developed more frequently in group B than in group A (p<0.001 and p=0.001, respectively). Liver-related causes of death were more common in group B than in group A (20/34 (59%) versus 1/9 (11%), p=0.021). HCC developed more frequently in men than in women (p=0.033). CONCLUSIONS: In elderly patients with chronic hepatitis C, cirrhosis and HCC develop more frequently in those with elevated transaminase levels than in those without elevated transaminase levels. Therefore, transaminase levels need to be suppressed below

Change of hepatitis B virus genotypes in acute and chronic infections in Japan.

During 35 years from 1971 to 2005, 153 patients with acute and 4,277 with chronic HBV infection visited the Toranomon Hospital in Tokyo, Japan. They were grouped into seven 5-year periods, and HBV genotypes/subgenotypes were determined. Patients with acute HBV infection were younger (P = 0.046), predominantly male (P = 0.004), possessed higher alanine aminotransferase levels (P < 0.001), positive more frequently for HBeAg (P < 0.001), and had lower HBV DNA loads (P = 0.014) than those with chronic infection. Sexual transmission was more frequent in patients with acute than chronic HBV infection (67% vs. 3%, P < 0.001). The number of patients with acute infection increased throughout 1971-2005. Patients with chronic infection increased since 1971, peaked in 1986-1990 and then decreased. The number of patients increased since 1990-2000 again, however, reflecting recent boost of acute HBV infection. The distribution of HBV genotypes was considerably different between patients with acute and chronic infections (A, B, and C: 28.6%, 10.3%, and 59.5% vs. 3.0%, 12.3%, and 84.5%, respectively, P < 0.001). Since 1991, genotype A foreign to Japan started to increase sharply in patients with acute infection, and gradually in those with chronic infection. There was a trend for the foreign subgenotype B2/Ba to increase recently (P < 0.05). Despite immunoprophylaxis of high-risk babies born to carrier mothers with hepatitis B e antigen, implemented nationally since 1986, acute and chronic infections with HBV have been increasing in Japan. Based on genotypes/subgenotypes changing with time, the resurgence of hepatitis B could be attributed to infections, with foreign HBV genotypes/subgenotypes, spreading swiftly by sexual contact.

Low risk of adefovir resistance in lamivudine-resistant chronic hepatitis B patients treated with adefovir plus lamivudine combination therapy: two-year follow-up.

BACKGROUND/AIMS: We studied the long-term efficacy (median follow-up of 28 months) of adefovir (ADV) in combination with lamivudine (LAM) in 132 LAM-resistant Japanese patients with chronic genotype C-dominant hepatitis B virus (HBV) infection. METHODS: The viral response (undetectable HBV-DNA by PCR assay) and the predictor of viral response were evaluated. The emergence of ADV-resistant mutants was investigated during the combination therapy. RESULTS: The cumulative probability of viral response was 69% at 12 months, and 81% at 24 months. Multivariate analysis identified baseline HBe antigen status (P=0.0001), aspartate aminotransferase level (AST) (P=0.001) and HBV-DNA level (P=0.002) as determinants of viral response to treatment. At the beginning of ADV therapy, substitutions at rtA181 (rtA181T and rtA181S) were identified in 3 patients (2.3%). In the remaining 129 patients, the rtM204 mutants were identified at baseline, and two (1.6%) of the 129 patients developed new ADV-resistant mutants; one was rtA181S and another was rtA181T plus rtN236T mutation. CONCLUSIONS: Adefovir and lamivudine combination therapy effectively suppressed viral replication and maintained the efficacy well in LAM-resistant patients with chronic HBV infection. Genotypic analysis indicated that the emergence of ADV-resistant mutants is rare, at least over a period of 2 years, in patients with combination therapy.

Loss of hepatitis B surface antigen from the serum of patients with chronic hepatitis treated with lamivudine.

Although loss of hepatitis B e antigen (HBeAg) from the serum is sought by treatment with lamivudine, clearance of hepatitis B surface antigen (HBsAg) is the eventual goal of any antiviral therapy. In a single hepatology center in the Metropolitan Tokyo, 486 patients with chronic hepatitis B were followed up for longer than 3 years after they started treatment with lamivudine. HBsAg disappeared from the serum in 17 (3.5%). Age >or=50 years and low HBsAg levels (hemagglutination titer or=50 years at the start of lamivudine was the only factor predicting the loss of HBsAg (hazard ratio: 2.96 [95% confidence interval: 1.14-7.68], P = 0.028). By the method of Kaplan-Meier performed on the 486 patients, the loss of HBsAg was estimated to occur in 3% and 13% of patients, respectively, who had received lamivudine therapy for 5 and 10 years. These results indicate that loss of HBsAg occurs in a minority (3.5%) of patients with chronic hepatitis B who receive lamivudine therapy and more frequently in those with lower HBsAg titers and older ages at the start of treatment.

Response to long-term lamivudine treatment in patients infected with hepatitis B virus genotypes A, B, and C.

Response to lamivudine treatment longer than 1 year was compared in 15 patients persistently infected with hepatitis B virus (HBV) genotype A, 38 with genotype B, and 449 with genotype C. Patients with genotype A were younger (median age 37 [range 24-49] vs. 47 [24-67] or 44 [18-73], P = 0.015), possessed hepatitis B e antigen (HBeAg) more frequently (73% vs. 21% or 56%, P < 0.001) and HBV DNA in higher levels (8.6 [6.1-8.7] vs. 6.5 [<3.7-8.7] or 6.5 [<3.7-8.7] log genome equivalents (LGE)/ml, P = 0.024) than those with genotype B or C. During lamivudine, YMDD mutants (89% vs. 53% or 42%, P = 0.0001) and breakthrough hepatitis developed more often (47% vs. 21% or 29%, P = 0.023) in patients with genotype A than B or C. YMDD mutants elicited more frequently in patients with genotype A than B or C who were positive (82% [9/11] vs. 25% [2/8] or 48% [117/245], P = 0.037) or negative for HBeAg (75% [3/4] vs. 30% [9/30] or 33% [68/204], P = 0.003). HBeAg (hazard ratio 2.1 [95% confidence interval 1.53-2.92], P < 0.001) and genotype A (2.78 [1.08-7.12], P = 0.034) enhanced the emergence of YMDD mutants by the Cox proportional hazard model. The risk for breakthrough hepatitis was increased by the baseline alanine aminotransferase level <500 IU/L (2.56 [1.82-5.50], P = 0.018), HBeAg (2.11 [1.40-3.16], P < 0.001), cirrhosis (1.92 [1.24-2.97], P = 0.004) and HBV DNA > or =8.0 LGE/ml (1.57 [1.04-2.36], P = 0.03); it was influenced by genotypes only in patients with HBeAg. In conclusion, HBV genotypes help in predicting response to long-term lamivudine treatment and development of YMDD mutants in patients with chronic hepatitis B.