Objectives Some single-centre studies have reported that MRSA carrying the staphylococcal cassette chromosome mec (SCCmec) type IV has been increasing in bloodstream infections (BSIs) in Japan. Therefore, we conducted nationwide surveillance for MRSA BSIs to investigate the extent of such change across Japan. Methods We recruited 51 Japanese hospitals from the Japanese Association for Infectious Diseases. MRSA isolates detected in two or more sets of blood cultures were collected between January and September 2019 and subjected to antimicrobial susceptibility testing. WGS was also performed to determine SCCmec and MLST types and detect drug-resistance and virulence genes. Results Two hundred and seventy MRSA isolates were collected from 45 hospitals. The major combination types were ST8 with SCCmec type IV (ST8-IV) (30.7%), ST1-IV (29.6%), ST2725-IV (9.5%), ST764-II (8.1%) and ST5-II (7.8%). However, there were regional differences among the major types. The most common types in eastern, western and northern Japan were ST1-IV, ST8-IV, and ST5-II and ST764-II, respectively. ST8-IV, ST1-IV and ST2725-IV exhibited greater susceptibility to clindamycin and minocycline than ST764-II and ST5-II, but erm(A) was detected in 93.8% and 100.0% of ST1-IV and ST2725-IV, respectively. Based on drug-resistance and virulence genes, characteristics of ST8-IV were different from those of ST1-IV and ST2725-IV. In addition, there were two major ST8-IV types with different characteristics. Conclusions This study revealed that SCCmec type IV replaced SCCmec type II in MRSA BSIs. In addition, SCCmec type IV was divided into several types with different characteristics.

Acute bacterial conjunctival infections are common, and this study identified the conjunctival bacterial community in infectious conjunctivitis cases seen at the outpatient clinic of Khanh Hoa General Hospital in Nha Trang, Vietnam from October 2016 through December 2017. Conjunctival swabs were collected and tested using conventional culture, PCR, and 16S ribosomal RNA sequencing. The study included 47 randomly selected patients. More than 98% of all DNA reads represented five bacterial phyla. Three of these phyla constituted 92% of all sequences (Firmicutes (35%), Actinobacteria (31%), and Proteobacteria (26%)). At the genus level, there were 12 common genera that constituted about 61% of all sequence reads. Seven of those genera were common (Streptococcus (10%), Cutibacterium (10%), Staphylococcus (7%), Nocardioides (7%), Corynebacterium 1 (5%), Anoxybacillus (5%), and Acinetobacter (5%)), which encompassed 49% of all reads. As for diversity analysis, there was no difference on PERMANOVA analysis (unweighted UniFrac) for sex (p = 0.087), chemosis (p = 0.064), and unclassified eyedrops (p = 0.431). There was a significant difference in cases with bilateral conjunctivitis (p = 0.017) and for using antibiotics (p = 0.020). Of the predominant phyla, Firmicutes had the highest abundance in bacterial conjunctivitis in this study. Pseudomonas as a resident commensal microbiota may have an important role in the prevention of infection.

ObjectivesSome single-center studies have reported that methicillin-resistant Staphylococcus aureus (MRSA) carrying the staphylococcal cassette chromosome mec (SCCmec) type IV has been increasing in bloodstream infections (BSIs) in Japan. Therefore, we conducted nationwide surveillance for MRSA BSI to verify that there is a change all over Japan.MethodsWe recruited 51 Japanese hospitals from the Japanese Association for Infectious Diseases. MRSA strains, which were detected in two or more sets of blood, were collected between January and September 2019. They were analyzed by antimicrobial susceptibility testing at Nagasaki University Hospital. Whole-genome sequencing was also performed to determine SCCmec typing and multilocus typing and detect drug-resistance and virulence genes.Results270 MRSA strains were collected from 45 hospitals. The major clones were ST8 with SCCmec type IV (ST8-IV) (30.7%), ST1-IV (29.6%), ST2725-IV (9.5%), ST764-II (8.1%), and ST5-II (7.8%). However, there were regional differences among the most major clones. The most common clones in western, eastern, and northern Japan were ST1-IV, ST8-IV, and ST5-II, respectively. ST8-IV, ST1-IV, and ST2725-IV exhibited lower drug resistance against clindamycin and minocycline than ST764-II and ST5-II, but erm(A) was detected in 93.8% and 100% of ST1-IV and ST2725-IV, respectively. Based on drug-resistance and virulence genes, characteristics of ST8-IV were different from those of ST1-IV and ST2725. In addition, the two major types were expected to be ST8-IV.ConclusionsThis study revealed that SCCmec type IV clones replaced SCCmec type II in MRSA BSI. In addition, three main types of SCCmec type IV clones have spread throughout Japan.

Background To determine the conjunctival bacterial community among the infectious conjunctivitis cases attending the outpatient clinic of Khanh Hoa General Hospital in Nha Trang, Vietnam from October 2016 through December 2017. Of all, 50 randomly selected samples using a computer generated random number list were included for microbiome identification. Conjunctival swabs were collected and tested using conventional culture, PCR, and 16S ribosomal RNA sequencing. Results The study included randomly selected 47 patients. More than 98% of all DNA reads represented five bacterial phyla. Three of these phyla constitute 92% of all sequences [Firmicutes (35%), Actinobacteria (31%), and Proteobacteria (26%)]. At the genus level, there were twelve common genera constituted about 61% of all the sequence reads. Seven of those genera were common [Streptococcus (10%), Cutibacterium (10%), Staphylococcus (7%), Nocardioides (7%), Corynebacterium 1 (5%), Anoxybacillus (5%), and Acinetobacter (5%)], which encompassed 49% of all reads. As for diversity analysis, there was no difference in PERMANOVA analysis (Unweighted UniFrac) for sex (P = 0.087), chemosis (P = 0.064) and unclassified eyedrops (P = 0.431). There was no difference in PERMANOVA analysis for pain (P = 0.315) and itching (P = 0.133). There was a statistical significant difference in cases with bilateral conjunctivitis (P = 0.017) and for using antibiotics (P = 0.020). Conclusion Firmicutes among the predominant phyla has the highest abundance in bacterial conjunctivitis in our study. Pseudomonas as a resident commensal microbiota has an important role for prevention of infection.