Dissemination of meticillin-resistant Staphylococcus aureus sequence type 8 (USA300) in Taiwan.

BACKGROUND: In Taiwan, sequence type (ST) 239 and ST59 were two major clones among meticillin-resistant Staphylococcus aureus (MRSA) clinical isolates in the past two decades. USA300 (ST8) prevailed in the Americas but not in outside areas. Recently USA300 (ST8) emerged and was increasingly identified in Taiwan; we thus conducted an island-wide study to explore the role of USA300 among MRSA isolates. METHODS: One hundred MRSA bloodstream isolates identified in 2020 from each of the six participating hospitals in Taiwan were collected and characterized. The first 10 ST8 isolates from each hospital were further analysed by whole-genome sequencing. RESULTS: Of the 590 confirmed MRSA isolates, a total of 22 pulsotypes and 21 STs were identified. The strain of pulsotype AI/ST8 was the most common lineage identified, accounting for 187 isolates (31.7%) and dominating in five of six hospitals, followed by pulsotype A/ST239 (14.7%), pulsotype C/ST59 (13.9%) and pulsotype D/ST59 (9.2%). Of the 187 pulsotype AI/ST8 isolates, 184 isolates were characterized as USA300 and clustered in three major sub-pulsotypes, accounting for 78%. Ninety per cent of the 60 ST8 isolates for whole-genome sequencing were clustered in three major clades. CONCLUSIONS: In 2020, USA300 became the most common clone of MRSA in Taiwan, accounting for >30% of MRSA bloodstream isolates island wide. Most of USA300 isolates circulating in Taiwan might have been imported on multiple occasions and evolved into at least three successful local clades. MRSA USA300 has successfully established its role in Taiwan, an area outside of the Americas.

Polycystic ovary syndrome with hyperandrogenism as a risk factor for non-obese non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is known to be associated with polycystic ovary syndrome (PCOS). However, most studies investigated the prevalence of NAFLD in obese PCOS patients. AIM: To compare the prevalence of non-obese NAFLD in women with or without PCOS, and to assess an independent association between PCOS and NAFLD in a non-obese Asian cohort. METHODS: This was a case-control study using a prospective PCOS cohort. After subjects with other potential causes of chronic liver disease were excluded, 275 non-obese women with PCOS and 892 non-obese controls were enrolled. NAFLD was determined by hepatic ultrasonography. Main outcomes were the prevalence of NAFLD on hepatic ultrasonography between non-obese women with or without PCOS, and an independent association between non-obese NAFLD and PCOS. RESULTS: Non-obese women with PCOS had a significantly higher prevalence of NAFLD than those without PCOS (5.5% vs. 2.8%, P = 0.027). PCOS was associated with non-obese NAFLD (odds ratio: 2.62, 95% confidence intervals: 1.25-5.48) after adjustment for age and body mass index (BMI). In women with PCOS, the level of androgenicity represented by free testosterone or free androgen index was associated with NAFLD after adjustment for age, BMI, lipid profile, insulin resistance or glycaemic status. CONCLUSIONS: Non-obese NAFLD is more prevalent in women with polycystic ovary syndrome than in those without. In non-obese patients with polycystic ovary syndrome, hyperandrogenemia may be an independent risk factor for non-obese NAFLD.

Association study of anti-Mullerian hormone and anti-Mullerian hormone type II receptor polymorphisms with idiopathic primary ovarian insufficiency.

STUDY QUESTION: Are the genetic polymorphisms of the anti-Müllerian hormone (AMH) and anti-Müllerian hormone type II receptor (AMHR2) genes associated with idiopathic primary ovarian insufficiency (POI) in a Korean population? SUMMARY ANSWER: The distribution of the AMH and the AMHR2 polymorphisms in a Korean POI population was not significantly different from controls. WHAT IS KNOWN ALREADY: AMH plays an important role in regulating both the primordial follicle recruitment and the cyclic selection of the antral follicles. The AMHR2 -482A>G polymorphism was associated with an earlier menopause and nulliparous women with the GG genotype had a 2.6 years earlier onset of menopause compared with the AA genotype women. Therefore, genetic variants in the AMH signal transduction pathway might affect the ovarian function of women. STUDY DESIGN, SIZE, DURATION: Case-control study. The subjects consisted of 211 idiopathic POI patients and 233 post-menopausal controls. PARTICIPANTS/MATERIALS, SETTING, METHODS: The frequency of the AMH Ile(49)Ser and AMHR2 -482A>G polymorphisms was analyzed in 211 patients with idiopathic POI and in 233 post-menopausal controls, and we also analyzed clinical characteristics, such as age at the time of POI and LH, FSH as well as estradiol levels according to the specific genotype. Genotyping for the AMH Ile(49)Ser and the AMHR2 -482A>G polymorphisms was performed by a minor groove binder primer/probe Taqman assay. MAIN RESULTS AND THE ROLE OF CHANCE: The genotype distributions and allele frequencies for the AMH Ile(49)Ser and the AMHR2 -482A>G polymorphisms were similar between the POI patients and the controls. Within POI population, the AMH Ile(49)Ser and the AMHR2 -482A>G polymorphisms were not associated with age at the time of POI and LH, FSH as well as estradiol levels. Haplotype analysis also showed no significant difference between groups. LIMITATIONS, REASONS FOR CAUTION: Study is limited to a Korean population. WIDER IMPLICATIONS OF THE FINDINGS: Our findings suggest that genetic variants in the AMH signal transduction pathway may not influence the susceptibility of idiopathic POI. This is the first report on the association between the AMH and AMHR2 polymorphisms and idiopathic POI. STUDY FUNDING/COMPETING INTEREST(S): No conflict of interest exists. This study was supported by a grant of Seoul National University Hospital Research Fund (04-2011-0870). TRIAL REGISTRATION NUMBER: N/A.

Atherogenic changes in low-density lipoprotein particle profiles were not observed in non-obese women with polycystic ovary syndrome.

STUDY QUESTION: Is a preponderance of small dense low-density lipoprotein-cholesterol (LDL-C) observed in non-obese women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: Non-obese Korean women with PCOS have no quantitative or qualitative changes in LDL-C profiles. WHAT IS KNOWN ALREADY: Small dense LDL particles (sd-LDL) are more atherogenic than large buoyant ones and are strongly associated with coronary artery disease independent of other risk factors. Many investigators have found an increased proportion of atherogenic sd-LDL or a decreased mean LDL particle size in women with PCOS, but all of these studies have been based primarily on obese or overweight women with PCOS. STUDY DESIGN, SIZE, DURATION: This was a case-control study evaluating complete lipid and lipoprotein profiles in 64 PCOS patients and 64 age- and BMI-matched controls. All women with PCOS in our study population were not obese. To determine the differences in the LDL particle profiles between PCOS phenotypes, the patients with PCOS were divided into two subgroups according to the presence of clinical or biochemical hyperandrogenism. PARTICIPANTS/MATERIALS, SETTING, METHODS: Using the Rotterdam criteria, we recruited 64 women (18-40 years) with PCOS who were attending a tertiary university hospital. A total of 64 premenopausal control women were matched with patients based on exact age and BMI (± 1.0 kg/m(2)). All the participants fell within the non-obese range of the BMI (<25 kg/m(2)) according to the definition of obesity for Asians. The LDL subfraction was analyzed by 3% polyacrylamide gel tube electrophoresis. Seven LDL subclasses were quantified and LDL subclasses 3-7 were small LDL subfractions. LDL subfraction scores were calculated based on the following weighted scoring system developed by the manufacturer: scores of <5.5 were categorized as phenotype A (large, buoyant LDLs), and those >5.5 were categorized as non-A phenotype (sd-LDLs). The system also determined the mean LDL particle size diameter. MAIN RESULTS AND THE ROLE OF CHANCE: There were no differences in the absolute level of LDL-C, mean LDL diameter or percentage of atherogenic sd-LDLs between PCOS patients and controls or between hyperandrogenic and non-hyperandrogenic PCOS subgroups. Also, none of the subjects showed a non-A LDL phenotype. The most notable finding of our study was the difference in the lipoprotein (a) levels and prevalence of its elevation in PCOS patients versus controls (P = 0.002 and P = 0.004, respectively), and between PCOS subgroups (P = 0.030 and P = 0.047, respectively). LIMITATIONS, REASONS FOR CAUTION: Inclusion of only non-obese subjects, small sample size and lack of information on other potential confounding factors, such as differences in diet and/or exercise patterns. WIDER IMPLICATIONS OF THE FINDINGS: Although our findings suggest that non-obese women with PCOS have no significant quantitative or qualitative changes in LDL-C profile, data on obese Korean women with PCOS could offer complementary findings about the possible relationship between the magnitude of obesity and LDL phenotype. Further investigations are needed to determine whether a change in lipoprotein (a) in non-obese women with PCOS is also found in other ethnic groups. STUDY FUNDING/COMPETING INTEREST(S): No conflict of interest exists. This study was supported by a grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (A100624). TRIAL REGISTRATION NUMBER: N/A.

Association of the interferon-γ gene (CA)n repeat polymorphism with endometriosis.

OBJECTIVE: To investigate whether the interferon-γ (IFN-γ) gene (CA)(n) repeat polymorphism is associated with susceptibility to endometriosis. DESIGN: Case-control study. SETTING: University Department of Obstetrics and Gynaecology. POPULATION: Women with (n = 622) and without (n = 442) endometriosis. METHODS: Genotyping was performed by fluorescent polymerase chain reaction (PCR) and gene-scan analysis. MAIN OUTCOME MEASURES: Genotype distribution and allele frequency of the dinucleotide (CA)(n) repeat polymorphism in the IFN-γ gene. RESULTS: Seven alleles (12-18 repeats) of the IFN-γ gene (CA)(n) repeat polymorphism were found. In both patients with endometriosis and controls the most common allele was composed of 13 repeats, followed by an allele of 15 repeats, and then by an allele of 12 repeats. Patients with endometriosis had a significantly higher incidence of genotypes with alleles composed of fewer repeats (12-13 repeats), compared with the controls (92.0 versus 84.4%, respectively, P < 001). CONCLUSIONS: Our results suggest that the (CA)(n) repeat polymorphism in the IFN-γ gene may be associated with a risk of endometriosis in the South Korean population.

Noradrenergic neurotransmission at PVN in locus ceruleus-induced baroreflex suppression in rats.

We investigated the role of ascending noradrenergic projections from the locus ceruleus (LC) to the paraventricular nucleus (PVN) of the hypothalamus in LC-induced suppression of the baroreceptor reflex (BRR) response in adult Sprague-Dawley rats maintained under pentobarbital anesthesia. On the basis of in vivo microdialysis and high-performance liquid chromatography-electrochemical detection, microinjection of L-glutamate (5 nmol) into the LC resulted in a site-specific increase in norepinephrine (NE) concentration in the dialysate collected from the parvocellular subnucleus of the PVN. The temporal course of this increase in extracellular NE concentration in the PVN coincided with the time course of inhibition elicited by the LC on the BRR response. Microinfusion of NE (10, 50, or 100 nM) into the parvocellular subnucleus of the PVN by reverse microdialysis also promoted a parallel increase in NE at the PVN and a reduction in the BRR response. Inhibition of the BRR response induced by microinjection into the PVN of the alpha 1-adrenoceptor agonist phenylephrine (10 nmol) or chemical activation of the LC was reversed by bilateral PVN microinjection of prazosin (100 pmol). However, local application to the PVN of the alpha 2- or beta-adrenoceptor agonist guanabenz (10 nmol) or isoproterenol (10 nmol) was ineffective. Our results suggest that NE released from the LC-PVN noradrenergic projection may participate in LC-induced suppression of the BRR response by activating the alpha 1-adrenoceptors at the parvocellular subnucleus of the PVN.