Performance assessment of ASTA MicroIDSys, a new matrix assisted laser desorption ionization-time of flight mass spectrometry system, for identification of viridans group streptococci.

The performance of the ASTA MicroIDSys system (ASTA), a new matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) system, was evaluated for the identification of viridans group streptococci (VGS) and compared with the results obtained with the Bruker Biotyper system (Bruker Daltonics). A total of 106 Streptococcus reference strains belonging to 24 species from the bacterial strain bank was analyzed using the two MALDI-TOF MS systems. Of the 106 reference strains tested, ASTA MicroIDSys and Bruker Biotyper correctly identified 84.9% and 81.1% at the species level, 100% and 97.2% at the group level and 100% and 98.1% at the genus level, respectively. The difference between the two systems was not statistically significant (P = 0.289). Out of 24 species, 13 species were accurately identified to the species level with 100% accurate identification rates with both systems. The accurate identification rates at the species level of ASTA MicroIDSys and Bruker Biotyper were 100% and 87.5% for the S. anginosus group; 78.4% and 73.5% for the S. mitis group; 91.7% and 91.7% for the S. mutans group; and 100% and 100% for the S. salivarius group, respectively. The ASTA MicroIDSys showed an identification performance equivalent to that of the Bruker Biotyper for VGS. Therefore, it would be useful for the identification of VGS strains in clinical microbiology laboratories.

Geographical structure of endosymbiotic bacteria hosted by Bathymodiolus mussels at eastern Pacific hydrothermal vents.

BACKGROUND: Chemolithoautotrophic primary production sustains dense invertebrate communities at deep-sea hydrothermal vents and hydrocarbon seeps. Symbiotic bacteria that oxidize dissolved sulfur, methane, and hydrogen gases nourish bathymodiolin mussels that thrive in these environments worldwide. The mussel symbionts are newly acquired in each generation via infection by free-living forms. This study examined geographical subdivision of the thiotrophic endosymbionts hosted by Bathymodiolus mussels living along the eastern Pacific hydrothermal vents. High-throughput sequencing data of 16S ribosomal RNA encoding gene and fragments of six protein-coding genes of symbionts were examined in the samples collected from nine vent localities at the East Pacific Rise, Galápagos Rift, and Pacific-Antarctic Ridge. RESULTS: Both of the parapatric sister-species, B. thermophilus and B. antarcticus, hosted the same numerically dominant phylotype of thiotrophic Gammaproteobacteria. However, sequences from six protein-coding genes revealed highly divergent symbiont lineages living north and south of the Easter Microplate and hosted by these two Bathymodiolus mussel species. High heterogeneity of symbiont haplotypes among host individuals sampled from the same location suggested that stochasticity associated with initial infections was amplified as symbionts proliferated within the host individuals. The mussel species presently contact one another and hybridize along the Easter Microplate, but the northern and southern symbionts appear to be completely isolated. Vicariance associated with orogeny of the Easter Microplate region, 2.5-5.3 million years ago, may have initiated isolation of the symbiont and host populations. Estimates of synonymous substitution rates for the protein-coding bacterial genes examined in this study were 0.77-1.62%/nucleotide/million years. CONCLUSIONS: Our present study reports the most comprehensive population genetic analyses of the chemosynthetic endosymbiotic bacteria based on high-throughput genetic data and extensive geographical sampling to date, and demonstrates the role of the geographical features, the Easter Microplate and geographical distance, in the intraspecific divergence of this bacterial species along the mid-ocean ridge axes in the eastern Pacific. Altogether, our results provide insights into extrinsic and intrinsic factors affecting the dispersal and evolution of chemosynthetic symbiotic partners in the hydrothermal vents along the eastern Pacific Ocean.

Tenosynovitis caused by Scedosporium apiospermum infection misdiagnosed as an Alternaria species: a case report.

BACKGROUND: Scedosporium apiospermum, which can usually be isolated from soil, polluted stream water and decaying vegetation, is increasingly recognized as an opportunistic dematiaceous fungus. The mortality rate of infection in immunocompromised hosts is over 50%. S. apiospermum is commonly responsible for dermal and epidermal infections (i.e., mycetoma) after traumatic penetration. CASE PRESENTATION: A 73-year-old woman was admitted to our hospital complaining of painful swelling and tenderness on the dorsum of the proximal left wrist and hand. The symptoms had persisted for approximately 2 months. A physical examination revealed a 4 x 3 cm, poorly defined, erythematous papule, which was fluctuant, with pustules and crusts on the dorsum of the left hand. CONCLUSIONS: We report a very rare case of tenosynovitis caused by S. apiospermum infection. We identified the infectious agent via molecular DNA sequencing. The infectious agent was initially misidentified as an Alternaria species by microscopic examination with lactophenol cotton blue (LPCB) staining. The infection was successfully treated with debridement and adjuvant fluconazole therapy.

Population subdivision of hydrothermal vent polychaete Alvinella pompejana across equatorial and Easter Microplate boundaries.

BACKGROUND: The Equator and Easter Microplate regions of the eastern Pacific Ocean exhibit geomorphological and hydrological features that create barriers to dispersal for a number of animals associated with deep-sea hydrothermal vent habitats. This study examined effects of these boundaries on geographical subdivision of the vent polychaete Alvinella pompejana. DNA sequences from one mitochondrial and eleven nuclear genes were examined in samples collected from ten vent localities that comprise the species' known range from 23°N latitude on the East Pacific Rise to 38°S latitude on the Pacific Antarctic Ridge. RESULTS: Multi-locus genotypes inferred from these sequences clustered the individual worms into three metapopulation segments - the northern East Pacific Rise (NEPR), southern East Pacific Rise (SEPR), and northeastern Pacific Antarctic Ridge (PAR) - separated by the Equator and Easter Microplate boundaries. Genetic diversity estimators were negatively correlated with tectonic spreading rates. Application of the isolation-with-migration (IMa2) model provided information about divergence times and demographic parameters. The PAR and NEPR metapopulation segments were estimated to have split roughly 4.20 million years ago (Mya) (2.42-33.42 Mya, 95 % highest posterior density, (HPD)), followed by splitting of the SEPR and NEPR segments about 0.79 Mya (0.07-6.67 Mya, 95 % HPD). Estimates of gene flow between the neighboring regions were mostly low (2 Nm < 1). Estimates of effective population size decreased with southern latitudes: NEPR > SEPR > PAR. CONCLUSIONS: Highly effective dispersal capabilities allow A. pompejana to overcome the temporal instability and intermittent distribution of active hydrothermal vents in the eastern Pacific Ocean. Consequently, the species exhibits very high levels of genetic diversity compared with many co-distributed vent annelids and mollusks. Nonetheless, its levels of genetic diversity in partially isolated populations are inversely correlated with tectonic spreading rates. As for many other vent taxa, this pioneering colonizer is similarly affected by local rates of habitat turnover and by major dispersal filters associated with the Equator and the Easter Microplate region.

Accuracy of Conventional PCR Targeting the 16S rRNA Gene with the Ot-16sRF1 and Ot-16sRR1 Primers for Diagnosis of Scrub Typhus: a Case-Control Study.

We retrospectively evaluated the accuracy of conventional PCR targeting the 16S rRNA gene (16S C-PCR) using the Ot-16sRF1/Ot-16sRR1 primers for diagnosing scrub typhus. The diagnosis of Orientia tsutsugamushi infection by 16S C-PCR presented an increased sensitivity of 87.0% and specificity of 100% compared with those obtained with other targets and is thus a simple and clinically useful method with good diagnostic accuracy.

First report of iliacus abscess caused by Salmonella enterica serovar Othmarschen.

The non-typhoidal bacterium Salmonella enterica subspecies enterica serovar Othmarschen (Salmonella Othmarschen) is a rare human pathogen. Abscess formation due to non-typhoidal Salmonella infections is a very rare complication in this antibiotic era. We report the first case of iliacus abscess after a short period of gastroenteritis which was caused by non-typhoidal Salmonella enterica belonging to group C1, serovar Othmarschen in a patient without any underlying conditions. A young female presented in our hospital complaining of pain in right hip joint area. She gave a history of watery diarrhea 3 days before the onset of pain. On examination the patient was ill-looking and there was tenderness in the right hip joint area. S. enterica was identified using 16S rRNA gene amplification by PCR and serotyped to be serovar Othmarschen from the pus sample of iliacus abscess. This is the first reported case of iliacus abscess due to Salmonella serover Othmarschen infection. Our case suggests that S. enterica serovar Othmarschen can cause severe focal infections associated with gastroenteritis. The literature on the rare association of Salmonella enterica and abscess formation is reviewed.

Evaluation of four methods of assigning species and genus to medically important bacteria using 16S rRNA gene sequence analysis.

The four methods for assigning bacterial species are the Clinical and Laboratory Standards Institute (CLSI), modified CLSI (mCLSI), phylogenetic analysis (PA) and closest match (CM) methods, these are used to identify the genus and species using 16S rRNA gene sequence results. In this study, the results of identification by these four methods of 37 aerobic reference strains, 30 anaerobic reference strains, 15 Acinetobacter reference strains and 167 Acinetobacter clinical strains were compared. The rates of accurate identification to the species level using the CLSI, mCLSI, PA and CM methods were as follows: 24.3, 86.5, 86.5 and 89.2%, respectively, for the 37 aerobic reference strains; 73.3%, 96.7%, 90.0% and 93.3%, respectively, for the 30 anaerobic reference strains; 40.0%, 93.3%, 100% and 93.3%, respectively, for the 15 Acinetobacter reference strains; and 53.9%, 90.4%, 95.8% and 90.4%, respectively, for the 167 Acinetobacter clinical strains. The rates of accurate identification to the genus level using the CLSI, mCLSI, PA, and CM methods were as follows: 91.9%, 91.9%, 94.6% and 91.9%, respectively, for the 37 aerobic reference strains; 100%, 100%, 100% and 100%, respectively, for all of the 30 anaerobic reference strains, 15 Acinetobacter reference strains and the 167 Acinetobacter clinical strains. The mCLSI is the most practical and pragmatic method for identification of species based on 16S rRNA sequences for hospital, research or industry laboratories because it performs well and involves a simple procedure.

8p11 myeloproliferative syndrome with t(1;8)(q25;p11.2): a case report and review of the literature.

8p11 myeloproliferative syndrome (EMS) is a rare disease characterized by myeloproliferative neoplasm (MPN) associated with eosinophilia and T or B lymphoblastic lymphoma/leukemia. EMS is defined by molecular disruption of the FGFR1 gene at the 8p11-12 chromosome locus, and various partner genes are associated with FGFR1 gene translocation or insertion. The different partner-FGFR1 fusion genes are associated with slightly different disease phenotypes. The present patient showed T lymphoblastic lymphoma in a cervical lymph node, involvement of malignant lymphoma in the skin, and MPN bone marrow morphology with peripheral monocytosis. Chromosome analysis of the patient showed t(1;8)(q25;p11.2). To our knowledge, only 2 cases of EMS with translocation of t(1;8)(q25;p11.2) have been previously reported. Including this case, all 3 cases with EMS with t(1;8)(q25;p11.2) showed MPN bone marrow morphology and peripheral monocytosis. These findings support that t(1;8)(q25;p11.2) is associated with peripheral monocytosis in EMS patients. Of the 2 cases of EMS with t(1;8)(q25;p11.2) which were previously reported, FGFR1 rearrangement was not confirmed in 1 case. Similarly, FGFR1 rearrangement in the present case was not detected by fluorescence in situ hybridization or reverse transcription-polymerase chain reaction. Further study is needed to identify other techniques that could be used to demonstrate FGFR1 rearrangement.

Exoskeletal trade-off between claws and carapace in deep-sea hydrothermal vent decapod crustaceans.

Limitations on energetic resources create evolutionary trade-offs, prompting us to investigate if investment in claw strength remains consistent across crustaceans living in diverse habitats. Decapod crustaceans living in deep-sea hydrothermal vents are ideal for this study due to their extreme environment. In this study, we investigated whether decapods (blind crab Austinograea sp. and the squat lobster Munidopsis lauensis) living in deep-sea hydrothermal vents prioritize investing in strong claws compared to the carapace, like coastal decapods. We analyzed exoskeleton morphology, mechanical properties, structures, and elemental composition in both the carapace and claws of four Decapoda species (two each from Brachyura and Anomura infraorders) in vent and coastal habitats. Coastal decapods had approximately 4 to 9 times more teeth on their claw cutting edge than the vent species. Further, only the coastal species exhibited higher firmness in their claws than in their carapaces. Each infraorder controlled exoskeletal hardness differently: Brachyura changed the stacking height of the Bouligand structure, while Anomura regulated magnesium content in the exoskeleton. The vent decapods may prioritize strengthening their carapace over developing robust claws, allocating resources to adapt to the harsh conditions of deep-sea hydrothermal vents. This choice might enhance their survival in the extreme environment, where carapace strength is crucial for protecting internal organs from environmental factors, rather than relying on the powerful claws seen in coastal decapods for a competitive advantage.

Establishment of Korean Pediatric Reference Intervals for Estradiol using Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry.

BACKGROUND: Ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) is a reliable and accurate method for measuring steroid hormone levels. There is an increasing need for sensitive and precise methods to measure estradiol in pediatric patients. Here, we established reference intervals for estradiol in healthy children using a UHPLC-MS/MS-based method for the first time in South Korea. METHODS: Serum estradiol was measured using a Sciex Triple QuadTM 6500 + UHPLC-MS/MS (Sciex, Framingham, MA, USA). Reference intervals for estradiol were established according to the CLSI document EP28-A3c:2008. The reference intervals were validated using serum samples from 634 pediatric patients, including neonates, children, and adolescents. Among them, 389 specimens were used in analysis of the specimen acceptance time. Statistical analysis was performed using MedCalc (MedCalc, Ostend, Belgium) and Analyse-it (Analyse-it Software Ltd., Leeds, United Kingdom) software. RESULTS: Reference intervals for boys (n = 297) were <16.6, <7.3, <19.0, <30.5, 7.6-96.5, and 10.6-134.4 pmol/L among those aged <1, 1-5, 6-9, 10-11, 12-14, and 15-17 years, respectively. Reference intervals for girls (n = 337) were <114.7, <24.2, <34.8, 8.0-177.0, 10.4-480.5, and 9.1-486.7 pmol/L among those aged <1, 1-5, 6-9, 10-11, 12-14, and 15-17 years, respectively. Overall, there was no effect of specimen acceptance time on estradiol measurements in boys or girls, except for that in the group aged 10-11 years. CONCLUSIONS: The reference intervals for healthy children were validated using a UHPLC-MS/MS-based method. The highly analytical sensitive UHPLC-MS/MS method may be useful for estradiol determination in pediatric patients.

Detection of amphotericin B resistance in Candida haemulonii and closely related species by use of the Etest, Vitek-2 yeast susceptibility system, and CLSI and EUCAST broth microdilution methods.

The emerging fungal pathogens Candida haemulonii and Candida pseudohaemulonii often show high-level resistance to amphotericin B (AMB). We compared the utilities of five antifungal susceptibility testing methods, i.e., the Etest using Mueller-Hinton agar supplemented with glucose and methylene blue (Etest-MH), the Etest using RPMI agar supplemented with glucose (Etest-RPG), the Vitek-2 yeast susceptibility system, and the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution methods, for the detection of AMB-resistant isolates of C. haemulonii and closely related species. Thirty-eight clinical isolates (8 C. haemulonii, 10 C. pseudohaemulonii, and 20 Candida auris isolates) were analyzed. Of the 18 C. haemulonii and C. pseudohaemulonii isolates, 18, 15, 18, 10, and 9 exhibited AMB MICs of >1 µg/ml by the Etest-MH, Etest-RPG, Vitek-2, CLSI, and EUCAST methods, respectively. All 20 C. auris isolates showed AMB MICs of ≤1 µg/ml by all five methods. Of the methods, the Etest-MH generated the broadest distribution of AMB MICs for all 38 isolates and showed the best discrimination between the C. haemulonii and C. pseudohaemulonii isolates (4 to 32 µg/ml) and those of C. auris (0.125 to 0.5 µg/ml). Taking the Etest-MH as the reference method, the essential agreements (within two dilutions) for the Etest-RPG, Vitek-2, CLSI, and EUCAST methods were 84, 92, 55, and 55%, respectively; the categorical agreements were 92, 92, 79, and 76%, respectively. This study provides the first data on the efficacy of the Etest-MH and its excellent agreement with Vitek-2 for discriminating AMB-resistant from AMB-susceptible isolates of these Candida species.

A regulatory hydrogenase gene cluster observed in the thioautotrophic symbiont of Bathymodiolus mussel in the East Pacific Rise.

The mytilid mussel Bathymodiolus thermophilus lives in the deep-sea hydrothermal vent regions due to its relationship with chemosynthetic symbiotic bacteria. It is well established that symbionts reside in the gill bacteriocytes of the mussel and can utilize hydrogen sulfide, methane, and hydrogen from the surrounding environment. However, it is observed that some mussel symbionts either possess or lack genes for hydrogen metabolism within the single-ribotype population and host mussel species level. Here, we found a hydrogenase cluster consisting of additional H2-sensing hydrogenase subunits in a complete genome of B. thermophilus symbiont sampled from an individual mussel from the East Pacific Rise (EPR9N). Also, we found methylated regions sparsely distributed throughout the EPR9N genome, mainly in the transposase regions and densely present in the rRNA gene regions. CRISPR diversity analysis confirmed that this genome originated from a single symbiont strain. Furthermore, from the comparative analysis, we observed variation in genome size, gene content, and genome re-arrangements across individual hosts suggesting multiple symbiont strains can associate with B. thermophilus. The ability to acquire locally adaptive various symbiotic strains may serve as an effective mechanism for successfully colonizing different chemosynthetic environments across the global oceans by host mussels.

Adjuvant antimicrobial activity and resensitization efficacy of geraniol in combination with antibiotics on Acinetobacter baumannii clinical isolates.

Adjuvant use of geraniol, a plant essential oil component, is known to increase the efficacy of antibiotics by acting as a potent inhibitor of efflux mechanisms. In this study, we assessed the effect of a geraniol-antibiotic combination in 21 Acinetobacter baumannii clinical isolates consisting of high efflux (HE) and low efflux (LE) activity groups. We determined the MIC for geraniol and the four antibiotics and evaluated the adjuvant antimicrobial activity and resensitization efficacy of adjuvant geraniol. Geraniol-antibiotic combinations significantly reduced the MIC of all four antibiotics (P < 0.0001), and the fold change in MIC decreased by 4 to >256-fold for tigecycline, >16 to >4,096-fold for ceftazidime, 1 to >4,096-fold for cefepime, and >2 to >4096-fold for ciprofloxacin. Importantly, geraniol showed adjuvant antimicrobial activity and resensitization efficacy when used in combination with antibiotics in 21 A. baumannii clinical isolates. However, there was no statistically significant difference between the HE and LE groups. Low concentrations (0.125% and 0.0625%) of geraniol showed no cytotoxic or hemolytic activity. Our study shows that geraniol, acting as an antibiotic adjuvant, is a good candidate for in vivo studies of combination therapy for the treatment of MDR/XDR A. baumannii infections.

Accuracy of ASTA MicroIDSys, a new matrix-assisted laser desorption/ionization time-of-flight mass spectrometry system, for the identification of Korean reference and clinical bacterial and yeast strains.

This study compared the accuracy of a new MALDI-TOF mass spectrometry system, ASTA MicroIDSys system, with that of MALDI Biotyper system for the identification of reference and clinical bacterial and yeast strains. The identification accuracy of the 2 systems was compared using a total of 406 strains comprising 142 aerobic and 180 anaerobic bacterial strains and 84 yeast strains. The genus and species identification rates were 98.0% and 89.4% using MicroIDSys and 96.1% and 89.4% using Biotyper, respectively. The species identification rates of MicroIDSys and Biotyper for aerobic bacteria were 93.0% and 97.2%, respectively, and those for anaerobic bacteria were 85.6% and 81.7%, respectively. The accuracy of yeast identification at the species level was 91.7% using MicroIDSys and 92.9% using Biotyper. These findings indicate that MicroIDSys could be useful for the accurate identification of bacteria and yeast in clinical microbiology laboratories.

Interspecies dissemination of the bla gene encoding PER-1 extended-spectrum ß-lactamase.

PER-1 extended-spectrum ß-lactamase-producing Gram-negative bacilli are resistant to oxyimino-cephalosporins. However, the bla(PER-1) gene has never been reported in Klebsiella pneumoniae. Here, we studied interspecies dissemination of the bla(PER-1) gene by horizontal transfer of Tn1213 among Acinetobacter baumannii, Pseudomonas aeruginosa, and K. pneumoniae. In a K. pneumoniae clinical isolate, the bla(PER-1) gene was located on a 150-kbp incompatibility group A/C plasmid.

Chromosome-encoded AmpC and CTX-M extended-spectrum ß-lactamases in clinical isolates of Proteus mirabilis from Korea.

Among 222 Proteus mirabilis clinical isolates collected from 17 hospitals in Korea in 2008, 28 (12.6%) and 8 (3.6%) isolates exhibited extended-spectrum ß-lactamase (ESBL) and AmpC phenotypes, respectively. The most common type of ESBL gene identified by PCR and sequencing experiments was bla(CTX-M-14a) (n = 12). The bla(CTX-M-90) (n = 4), bla(CTX-M-15) (n = 3), bla(CTX-M-12) (n = 3), bla(CTX-M-2) (n = 2), bla(CTX-M-14b) (n = 1), bla(TEM-52) (n = 5), and bla(SHV-12) (n = 1) genes were also detected. Eight isolates carried an AmpC ß-lactamase gene, such as bla(CMY-2) (n = 6) or bla(DHA-1) (n = 2). All bla genes encoding CTX-M-1- and CTX-M-9-type enzymes and all bla(CMY-2) genes were preceded by ISEcp1-like elements. The bla(CTX-M-2) gene found in two isolates was located on a complex class 1 integron. The bla(DHA-1) gene was preceded by a transcriptional regulator gene and was followed by phage shock protein genes. The bla(CTX-M) genes were located on the chromosome in 21 isolates. A plasmid location for the bla(CTX-M) gene was found in only four isolates: the bla(CTX-M-14a) gene was located on ∼150-kbp IncA/C plasmids in three isolates and on a ∼50-kbp IncN plasmid in one isolate. The bla(TEM-52) gene was located on ∼50-kbp IncN plasmids in all five isolates. The AmpC ß-lactamase genes were located on the chromosome in seven of eight isolates; one isolate carried the bla(CMY-2) gene on a ∼150-kbp IncA/C plasmid. Our results show that a chromosomal location of CTX-M ESBL and AmpC ß-lactamase genes in P. mirabilis is no longer an unusual phenomenon in hospital environments.

Relationships between Relative Expression of RND Efflux Pump Genes, H33342 Efflux Activity, Biofilm-Forming Activity, and Antimicrobial Resistance in Acinetobacter baumannii Clinical Isolates.

Various mechanisms underlying antimicrobial resistance in Acinetobacter baumannii have been reported. However, the relationships between efflux pump activity, biofilm formation, and antimicrobial resistance in A. baumannii is controversial. In this study, we investigated the relative expression of RND efflux pump genes, H33342 efflux activity, and biofilm-forming activity in 120 A. baumannii clinical isolates, examined their potential relationships with each other, and statistically analyzed their effects on antibiotic resistance. High adeB expression and high H33342 efflux activity were correlated with low biofilm-forming activity. High adeB expression was significantly correlated with resistance to tigecycline and cefotaxime, but not with the multidrug resistance (MDR) phenotype. Importantly, only high adeJ expression was significantly correlated with the MDR phenotype and was correlated with resistance to various antibiotics. However, we found no significant correlation between adeJ expression and biofilm-forming activity. Furthermore, adeG expression was not correlated with antibiotic resistance and biofilm-forming activity. The results of multivariate analysis showed that adeB overexpression and high H33342 efflux activity were related to biofilm-forming activity, and only adeJ overexpression was significantly associated with the MDR phenotype, highlighting the importance of adeJ overexpression.

Enterobacter nimipressuralis as a cause of pseudobacteremia.

BACKGROUND: The clinical significance of the Enterobacter nimipressuralis as human pathogens remains unclear. CASE PRESENTATIONS: The microbiologic culture monitoring system of sterile body fluids revealed on an episode of Enterobacter cloacae and Enterobacter amnigenus in blood culture results on the same day; the antibiotic sensitivity and MIC were nearly the same for both species. First patient was a healthy woman with postmenopausal syndrome, while second patient with herpes zoster. Both patients had febrile sensations without signs of bacteremia. E. amnigenus was also cultured from the unused package of salined cotton in the container through epidemiologic investigation. The cultured Enterobacter species were all identified as E. nimipressuralis through hsp60 gene sequencing and infrequent-restriction-site PCR (IRS-PCR). CONCLUSION: When an unusual microorganisms such as E. nimipressuralis is isolated from blood of a patient with no clinical signs of sepsis, a pseudobacteremia should be suspected. When the antibiogram and MIC test results of bacterial cultures from two or more patients are nearly the same, although the species involved may appear different, it may be necessary to prove that they are the same species through molecular methods. The microbiologic cultures monitoring system will probably help to detect pseudobacteremia and other pseudo infections through reliable and fast identification.

Dataset supporting description of the new mussel species of genus Gigantidas (Bivalvia: Mytilidae) and metagenomic data of bacterial community in the host mussel gill tissue.

This article contains supplementary data from the research paper entitled "A newly discovered Gigantidas bivalve mussel from the Onnuri Vent Field on the northern Central Indian Ridge" [1], describes a new mussel species within the subfamily Bathymodiolinae named Gigantidas vrijenhoeki. Data are comprised of two parts: 1) shell image and molecular analyses of G. vrijenhoeki and 2) metagenomic community analyses of gill-associated symbiotic bacteria on G. vrijenhoeki. G. vrijenhoeki data were obtained from type specimens described in Jang et al. 2020 [1]. The molecular analysis was conducted by calculating genetic distance at intra- and inter-specific level within genus Gigantidas based on the sequence data of two mitochondrial genes (COI and ND4). The metagenomic dataset of gill-associated symbionts were generated by Illumina Miseq sequencing of the V3-V4 region of 16S rRNA from 12 specimens of G. vrijenhoeki collected from the same vent site, Onnuri Vent Field.

Serotype Distribution and Antimicrobial Resistance of Invasive and Noninvasive Streptococcus pneumoniae Isolates in Korea between 2014 and 2016.

BACKGROUND: Several factors contribute to differences in Streptococcus pneumoniae serotype distribution. We investigated the serotype distribution and antimicrobial resistance of S. pneumoniae isolated between 2014 and 2016 in Korea. METHODS: We collected a total of 1,855 S. pneumoniae isolates from 44 hospitals between May 2014 and May 2016, and analyzed the serotypes by sequential multiplex PCR. We investigated the distribution of each serotype by patient age, source of the clinical specimen, and antimicrobial resistance pattern. RESULTS: The most common serotypes were 11A (10.1%), followed by 19A (8.8%), 3 (8.5%), 34 (8.1%), 23A (7.3%), and 35B (6.2%). The major invasive serotypes were 3 (12.6%), 19A (7.8%), 34 (7.8%), 10A (6.8%), and 11A (6.8%). Serotypes 10A, 15B, 19A, and 12F were more common in patients ≤5 years old, while serotype 3 was more common in patients ≥65 years old compared with the other age groups. The coverage rates of pneumococcal conjugate vaccine (PCV)7, PCV10, PCV13, and pneumococcal polysaccharide vaccine 23 were 11.8%, 12.12%, 33.3%, and 53.6%, respectively. Of the 1,855 isolates, 857 (46.2%) were multi-drug resistant (MDR), with serotypes 11A and 19A predominant among the MDR strains. The resistance rates against penicillin, cefotaxime, and levofloxacin were 22.8%, 12.5%, and 9.4%, respectively. CONCLUSIONS: There were significant changes in the major S. pneumoniae serotypes in the community. Non-PCV13 serotypes increased in patients ≤5 years old following the introduction of national immunization programs with the 10- and 13-polyvalent vaccines.