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To compare the molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) isolates between an old, urban hospital and a new, rural hospital over the same time period. Methods: The molecular characteristics of 398 MRSA bloodstream isolates collected between 2007 and 2013 from two hospitals in Taiwan were analyzed retrospectively; 202 isolates were from the old hospital and 196 from the new hospital (opened in 2007). Results: The rate of resistance to multiple antibiotics was significantly higher in the old hospital (93%) than in the new hospital (81%) (p < 0.001). Genetic community-associated MRSA carrying staphylococcal cassette chromosome (SCC) type IV or V accounted for 58% of all MRSA isolates in the new hospital, significantly higher than the rate in the old hospital (p = 0.018). The rate of spa t037-SCCmec III MRSA was significantly lower in the new hospital than in the old hospital (p = 0.02). A significant decreasing trend in spa t002-SCCmec II MRSA isolates was observed in the old hospital (p = 0.006), while the proportion of spa t037-SCCmec III MRSA decreased significantly in the new hospital (41.7% to 26.1%, p = 0.022). Conclusions: The rate of multiple antibiotic resistance and the molecular characteristics of MRSA differed significantly between the old and new hospitals and changed over time.

In this study, we investigated the molecular evolution and phylodynamics of respiratory syncytial virus (RSV) over 10 consecutive seasons (2008–2017) and the genetic variability of the RSV genotypes ON1 and BA in central Taiwan. The ectodomain region of the G gene was sequenced for genotyping. The nucleotide and deduced amino acid sequences of the second hypervariable region of the G protein in RSV ON1 and BA were analyzed. A total of 132 RSV-A and 81 RSV-B isolates were obtained. Phylogenetic analysis revealed that the NA1, ON1, and BA9 genotypes were responsible for the RSV epidemics in central Taiwan in the study period. For RSV-A, the NA1 genotype predominated during the 2008–2011 seasons. The ON1 genotype was first detected in 2011 and replaced NA1 after 2012. For RSV-B, the BA9 and BA10 genotypes cocirculated from 2008 to 2010, but the BA9 genotype has predominated since 2012. Amino acid sequence alignments revealed the continuous evolution of the G gene in the ectodomain region. The predicted N-glycosylation sites were relatively conserved in the ON1 (site 237 and 318) and BA9 (site 296 and 310) genotype strains. Our results contribute to the understanding and prediction of the temporal evolution of RSV at the local level.

Background The factors to predict the progression of Mycoplasma pneumoniae infection remain inconclusive. Therefore, we investigated macrolide resistance prevalence, M. pneumoniae genotype, and clinical characteristics of childhood M. pneumoniae respiratory tract infections in Taiwan. Methods A total of 295 children hospitalized with respiratory tract infections with positive serological M. pneumoniae immunoglobulin M test results were enrolled in this 3-year prospective study. Oropharyngeal swabs were obtained for M. pneumoniae cultures and PCR tests. All M. pneumoniae specimens were further characterized by P1 typing, multilocus variable-number tandem-repeat analysis (MLVA), and macrolide resistance genotyping. The clinical characteristics and blood cytokine profiles were analyzed accordingly. Results Of 138 M. pneumoniae specimens, type I P1 was the predominant (136/138, 98.6%). MLVA type P (4-4-5-7-2) was the leading strain (42/138, 30.4%), followed by type J, U, A, and X. The overall macrolide-resistant rate was 38.4% (53/138); the resistance rate increased dramatically yearly: 10.6% in 2017, 47.5% in 2018, and 62.5% in 2019 (P &lt; .001). All macrolide-resistant M. pneumoniae (MRMP) harbored the A2063G mutation and were MLVA type 4-5-7-2 (49/53, 92.5%), especially type U and X. No significant differences in clinical symptoms, duration of hospital stay, and radiographic findings were identified among patients between MRMP and macrolide-sensitive M. pneumoniae (MSMP) groups. Patients with MRMP infection had more febrile days before and during hospitalization; higher IL-13 and IL-33 levels than patients with MSMP infection (P &lt; .005). Conclusions MRMP surged in Taiwan throughout the study period, but macrolide resistance was not a determinant factor of clinical severity.