Characterization of Staphylococcus aureus Isolated from Non-Native Patients with Skin and Soft Tissue Infections in Shanghai

Background

Staphylococcus aureus is one predominant cause of skin and soft-tissue infections (SSTIs), but little information exists regarding the characterization of S. aureus from non-native patients with SSTIs in China.

Methods

In this study, we enrolled 52 non-native patients with S. aureus SSTIs, and 65 native control patients with S. aureus SSTIs in Shanghai. 52 and 65 S. aureus isolates were collected from both groups, respectively. S. aureus isolates were characterized by antimicrobial susceptibility testing, toxin gene detection, and molecular typing with sequence type, spa type, agr group and SCCmec type.

Results

Methicillin-resistant S. aureus (MRSA) was detected in 8 non-native patients and 14 native patients with SSTIs. Overall, antimicrobial susceptibilities of S. aureus isolated from non-native patients were found higher than those from native patients. CC59 (ST338 and ST59) was found in a total of 14 isolates (4 from non-native patients; 10 from native patients), 9 of which were carrying lukS/F-PV (3 from non-native patients; 6 from native patients). ST7 was found in 12 isolates and all 12 isolates were found in native patients. The livestock-associated clone ST398 was found in 11 isolates (6 from non-native patients; 5 from native patients), and 5 ST398 lukS/F-PV-positive methicillin-susceptible S. aureus (MSSA) were all discovered among non-native patients. The molecular epidemiology of S. aureus isolated from non-native patients was quite different from those from native patients. lukS/F-PV was more frequent in isolates originating from non-native patients with SSTIs compared to native patients (31 vs. 7, P <0.0001).

Conclusions

CC59 was the most common clonal complex among patients with SSTIs in Shanghai. The other most common sequence types were ST7 and Livestock ST398. The molecular epidemiology of S. aureus isolated from non-native patients was quite different from those from native patients. S. aureus isolated from non-native patients was more likely to carry lukS/F-PV.     

Dactylogyrids (Monogenoidea: Polyonchoinea) parasitising the gills of snappers (Perciformes: Lutjanidae): Species of Euryhaliotrema Kritsky & Boeger, 2002 from the golden snapper Lutjanus johnii (Bloch) off northern Australia, with a redescription of Euryhaliotrema johni (Tripathi, 1959) and descriptions of two new species

Three species of Euryhaliotrema Kritsky & Boeger, 2002 (Monogenoidea: Dactylogyridae) were collected from the gills of four golden snapper Lutjanus johnii (Bloch) (Lutjanidae) from the marine and brackish waters off Darwin, Northern Territory, Australia. Type-specimens of Ancyrocephalus johni Tripathi, 1959 apparently have not survived and the possibility existed that the species was based on specimens representing more than one species. Euryhaliotrema johni (Tripathi, 1959) (sensu Young, 1968) was redescribed and determined to most likely represent A. johni, originally described from the River Hooghly, Diamond Harbour, India. Two new species were described. Euryhaliotrema longibaculoides n. sp. was most similar to Euryhaliotrema longibaculum (Zhukov, 1976) Kritsky & Boeger, 2002 from Lutjanus spp. from the western Atlantic Ocean. It differed from E. longibaculum by having a male copulatory organ (MCO) with an elongate comparatively delicate shaft and a bulbous base (MCO U- or J-shaped with funnel-shaped base in E. longibaculum). Based on the comparative morphology of the haptoral sclerites, Euryhaliotrema lisae n. sp. was most similar to Euryhaliotrema cryptophallus Kritsky & Yang, 2012 from the gills of the mangrove red snapper Lutjanus argentimaculatus (Forsskål) from the South China Sea. Euryhaliotrema lisae differed from E. cryptophallus by having a copulatory complex with an obvious weakly sclerotised J-shaped MCO (MCO cryptic, delicate, and with a shaft comprising about one counterclockwise ring in E. cryptophallus).     

Niche separation of species of entomopathogenic fungi within the genera Metarhizium and Beauveria in different cropping systems in Mexico

Entomopathogenic fungi from the genera Beauveria and Metarhizium, were isolated from soil using the Galleria mellonella baiting method, and from infected white grub larvae from a diversity of cropping systems in Puebla and Guanajuato, Mexico. Isolates were identified to species level using Bloc and Elongation Factor 1-α sequence information. Although widespread, Beauveria bassiana (41 isolates) was only isolated from soil and not from infected white grubs. In contrast, Beauveria pseudobassiana (six isolates) was predominantly isolated from white grub larvae (only one isolate from soil). Haplotype analysis of B. bassiana Bloc sequences identified 25 haplotypes indicating substantial genetic diversity; neither geographical origin nor crop type explained this genetic variation. Metarhizium brunneum (three isolates) and Metarhizium robertsii (17 isolates) were also only isolated from soil, while Metarhizium anisopliae (six isolates) and Metarhizium pingshaense (four isolates) were only isolated from white grub larvae. M. anisopliae was only found infecting Paranomala species while M. pingshaense was only found infecting Phyllophaga species. Species diversity in Metarhizium was influenced by crop type. Our results showed that entomopathogenic fungi species could co-exist in the same soil ecosystem but in separate niches. The potential ecological roles of these species are discussed.     

Stereochemistry of 2-aminopimelic acid and related amino acids in three species of asplenium

We previously reported two free D-amino acids, D-2-aminopimelic acid (D-APA) and trans-3,4-dehydro-D-2-aminopimelic acid (D-Δ-APA), from Asplenium unilaterale. In the present work we isolated 4-hydroxy-2-aminopimelic acid (OH-APA) from the same plant and determined it to be the α-L-form. We also investigated the configurations of these amino acids isolated from A. prolongatum and A. wilfordii which are morphologically distinct from A. unilaterale. In A. prolongatum, APA was the D- and OH-APA was the L-isomer. In contrast, APA from A. wilfordii was partially racemized and the degree of racemization was significantly different in plant material collected in July and November, L:D = 3:2 and 3:7, respectively. In A. wilfordii OH-APA was almost pure L- and Δ-APA was mostly the D-isomer.     

Determination of growth-limiting nutrients for red species of Oscillatoria and two ‘oligotrophic’ diatoms

Laboratory batch experiments with dilute phytoplankton communities were carried out to determine growth-limiting nutrients and the degree of growth limitation for Asterionella formosa, Hass., Tabellaria fenestrata (Lyngb.) Kütz. and red species of Oscillatoria under specific temperature and light conditions. Water samples from five Norwegian lakes with average epilimnetic total phosphorus concentrations ranging from 5 to 30 µg P per 1 were investigated. Both enrichment and transplant experiments were carried out. In samples from the most oligotrophic lakes (Lake Randsfjorden and Lake Tyrifjorden) phosphorus was found to be the growth-limiting nutrient. In samples from Lake Mjøsa silicate was also growth-limiting for the diatoms, while nitrogen could be limiting for both asterionella and Oscillatoria from Lake Steinsfjorden. Phosphorus was often the only limiting nutrient determined for Oscillatoria in Lake Gjersjøen (the most eutrophic of the lakes). In samples from this lake, however, Asterionella was also growth-limited directly or indirectly as a result of high (pH > 9). This was also found for Asterionella and Tabellaria from lake Mjøsa by means of transplant experiments. Oscillatoria from Lake Gjersjøen could not grow in filtered water from Lake Mjøsa but obtained maximum growth rate after addition of phosphate and chelated iron in combination.     

Stereoselectivity of the interactions of thioglucoside glucohydrolase and epithiospecifier protein from various sources

(S)-2-Hydroxy-3-butenylglucosinolate (epi-progoitrin) was converted to erythro- and threo-1-cyamo-2-hydroxy-3,4-epithiobutanes by combinations of thioglucoside glucohydrolase and epithiospecifier protein (ESP) from various sources. In all combinations studied the erythro/threo product ratio was about 1.4, except when the thioglucoside glucohydrolase was from Sinapis alba L. and the ESP from Brassica campestris in which case the ratio was about 1.8.     

Comparison of Leishmania killicki (syn. L. tropica) and Leishmania tropica Population Structure in Maghreb by Microsatellite Typing

Leishmania (L.) killicki (syn. L. tropica), which causes cutaneous leishmaniasis in Maghreb, was recently described in this region and identified as a subpopulation of L. tropica. The present genetic analysis was conducted to explore the spatio-temporal distribution of L. killicki (syn. L. tropica) and its transmission dynamics. To better understand the evolution of this parasite, its population structure was then compared with that of L. tropica populations from Morocco. In total 198 samples including 85 L. killicki (syn. L. tropica) (from Tunisia, Algeria and Libya) and 113 L. tropica specimens (all from Morocco) were tested. Theses samples were composed of 168 Leishmania strains isolated from human skin lesions, 27 DNA samples from human skin lesion biopsies, two DNA samples from Ctenodactylus gundi bone marrow and one DNA sample from a Phlebotomus sergenti female. The sample was analyzed by using MultiLocus Enzyme Electrophoresis (MLEE) and MultiLocus Microsatellite Typing (MLMT) approaches. Analysis of the MLMT data support the hypothesis that L. killicki (syn. L. tropica) belongs to the L. tropica complex, despite its strong genetic differentiation, and that it emerged from this taxon by a founder effect. Moreover, it revealed a strong structuring in L. killicki (syn. L. tropica) between Tunisia and Algeria and within the different Tunisian regions, suggesting low dispersion of L. killicki (syn. L. tropica) in space and time. Comparison of the L. tropica (exclusively from Morocco) and L. killicki (syn. L. tropica) population structures revealed distinct genetic organizations, reflecting different epidemiological cycles.     

Diversity of cold-active protease-producing bacteria from arctic terrestrial and marine environments revealed by enrichment culture

A new approach for enrichment culture was applied to obtain cold-active protease-producing bacteria for marine and terrestrial samples from Svalbard, Norway. The method was developed for the enrichment of bacteria by long-term incubation at low temperatures in semi-solid agar medium containing meat pieces as the main source of carbon and energy. ZoBell and 0.1× nutrient broth were added for marine and terrestrial microorganisms, respectively, to supply basal elements for growth. One to three types of colonies were observed from each enrichment culture, indicating that specific bacterial species were enriched during the experimental conditions. Among 89 bacterial isolates, protease activity was observed from 48 isolates in the screening media containing skim milk. Good growth was observed at 4°C and 10°C while none of the isolates could grow at 37°C. At low temperatures, enzyme activity was equal to or higher than activity at higher temperatures. Bacterial isolates were included in the genera Pseudoalteromonas (33 isolates), Arthrobacter (24 isolates), Pseudomonas (16 isolates), Psychrobacter (6 isolates), Sphingobacterium (6 isolates), Flavobacterium (2 isolates), Sporosarcina (1 isolate), and Stenotrophomonas (1 isolate). Protease activity was observed from Pseudoalteromonas (33 isolates), Pseudomonas (10 isolates), Arthrobacter (4 isolates), and Flavobacterium (1 isolate).     

Poly(3-Hydroxybutyrate) Degradation in Ralstonia eutropha H16 Is Mediated Stereoselectively to (S)-3-Hydroxybutyryl Coenzyme A (CoA) via Crotonyl-CoA

Degradation of poly(3-hydroxybutyrate) (PHB) by the thiolytic activity of the PHB depolymerase PhaZ1 from Ralstonia eutropha H16 was analyzed in the presence of different phasins. An Escherichia coli strain was constructed that harbored the genes for PHB synthesis (phaCAB), the phasin PhaP1, and the PHB depolymerase PhaZ1. PHB was isolated in the native form (nPHB) from this recombinant E. coli strain, and the in vitro degradation of the polyester was examined. Degradation resulted in the formation of the expected 3-hydroxybutyryl coenzyme A (3HB-CoA) and in the formation of a second product, which occurred in significantly higher concentrations than 3HB-CoA. This second product was identified by liquid chromatography mass spectrometry (LC-MS) as crotonyl-CoA. Replacement of PhaP1 by PhaP2 or PhaP4 resulted in a lower degradation rate, whereas the absence of the phasins prevented the degradation of nPHB by the PHB depolymerase PhaZ1 almost completely. In addition, the in vitro degradation of nPHB granules isolated from R. eutropha H16 (wild type) and from the R. eutropha ΔphaP1 and ΔphaP1-4 deletion mutants was examined. In contrast to the results obtained with nPHB granules isolated from E. coli, degradation of nPHB granules isolated from the wild type of R. eutropha yielded high concentrations of 3HB-CoA and low concentrations of crotonyl-CoA. The degradation of nPHB granules isolated from the ΔphaP1 and ΔphaP1-4 deletion mutants of R. eutropha was significantly reduced in comparison to that of nPHB granules isolated from wild-type R. eutropha. Stereochemical analyses of 3HB-CoA revealed that the (R) stereoisomer was collected after degradation of granules isolated from E. coli, whereas the (S) stereoisomer was collected after degradation of granules isolated from R. eutropha. Based on these results, a newly observed mechanism in the degradation pathway for PHB in R. eutropha is proposed which is connected by crotonyl-CoA to the β-oxidation cycle. According to this model, the NADPH-dependent synthesis of PHB with (R)-3HB-CoA as the intermediate and the PHB degradation yielding (S)-3HB-CoA, which is further converted in an NAD-dependent reaction, are separated.     

Prevalence and Genetic Diversity of Campylobacter spp. in Environmental Water Samples from a 100-Square-Kilometer Predominantly Dairy Farming Area

Water samples were taken systematically from a 100-km² area of mainly dairy farmland in northwestern England and examined for Campylobacter spp. Pulsed-field gel electrophoresis-restriction fragment length polymorphism (PFGE-RFLP) and flaA strain typing of Campylobacter jejuni and Campylobacter coli isolates were done. Data on the water source and the adjacent environment were recorded and examined as explanatory variables. Campylobacter spp. were isolated from 40.5% (n = 119) of the water samples tested. C. jejuni was isolated from 14.3%, C. coli was isolated from 18.5%, and Campylobacter lari was isolated from 4.2% of the samples. Campylobacter hyointestinalis was not isolated from any water source. The difference in prevalence between water types (trough, running, and standing) was significant (P = 0.001). C. jejuni was the species most commonly isolated from trough-water and running-water sources, while C. coli was the most frequently isolated from standing water (P < 0.001). No association was found between the presence of Escherichia coli and that of Campylobacter spp. The final multivariable logistic regression model for Campylobacter spp. included the following variables: water source, soil type, aspect, and amount of cattle fecal material in the environment (fecal pat count). Strain typing demonstrated a diverse population of C. jejuni and the presence of a common C. coli flaA type that was widely distributed throughout the area. Most of the isolates within the common flaA type were discriminated by PFGE-RFLP. These findings suggest a possible role for environmental water in the epidemiology of Campylobacter spp. in a farming environment.     

Predominance of vanA Genotype among Vancomycin-Resistant Enterococcus Isolates from Poultry and Swine in Costa Rica

The use of avoparcin as a growth promoter is considered to have selected for vancomycin-resistant enterococci (VRE). In Costa Rica, the use of avoparcin for poultry and swine was intensive until the product was withdrawn from the market in 2000. We evaluated the presence of VRE in poultry, swine, and cattle fecal samples obtained during 1998 and 1999. A total of 185 VRE isolates were recovered from 116 out of 893 samples. Enterococcus faecium was the most frequently isolated species (50.8%), being predominant among poultry (71.6%) and swine (37.7%) isolates, but it was not recovered from the bovine samples. The second-most-frequently-isolated species from poultry and swine, respectively, were E. durans (23.2%) and E. faecalis (21.7%). E. casseliflavus was the only species obtained from bovine samples, but it was not found among the avian isolates. An evident predominance of the vanA determinant among vancomycin-resistant enterococcal species from poultry and swine, but not from cattle, was observed and was similar to the situation in European countries before avoparcin was forbidden. The diversity of the vanA determinant in the isolates was assessed by detection of the IS1251 insertion in the vanSH intergenic region and of the IS1476 insertion in the vanXY intergenic region. However, in none of the 154 vanA⁺ isolates recovered in this study were those insertions detected.     

Cloning and nucleotide sequence of the urea amidolyase gene from Candida utilis

Urea amidolyase (EC 3.5.1.45) is an important multi-functional enzyme for the degradation of urea. The urea amidolyase gene from Candida utilis CA(u)-37 (DUR1,2^c) was cloned by plaque hybridization, and the nucleotide sequences of DUR1, 2^c and its flanking regions were determined. DUR1, 2^c was found to be composed of 5,490 base pairs and 1,830 amino acid residues. Using Edman degradation of the purified enzyme, it was revealed that the amino-terminal residue (methionine) was processed for maturation. A TATA-box like sequence was found 112 bases upstream from the translation start site (ATG). The site of the poly (A) tail was found 54 bases downstream from the translation stop site (TGA), since cDNA of DUR1, 2^c was synthesized from mRNA and sequenced. The nucleotide sequences of the urea amidolyase gene from Saccharomyces cerevisiae and DUR1, 2^c were very similar to each other (65.3%), as were the deduced amino acid sequences (67.2%). The molecular weight of DUR1, 2^c was calculated to be 200,700. This value corresponded to the result obtained from SDS-polyacrylamide gel electrophoresis of the purified enzyme. The enzyme functions in a dimeric form. Three important regions were found in the amino acid sequence of urea amidolyase through the homology search. It was predicted that each region was equivalent to the active site of allophanate hydrolase, that of urea carboxylase, and the biotin-binding site. This was verified by deletion analysis of the DUR1, 2^c gene in S. cerevisiae. The function of the upstream region of the C. utilis gene is also discussed.     

Steroid metabolism in granulosa and theca interna cells from preovulatory follicles of domestic hen (Gallus domesticus)

The capability of granulosa and theca interna cells, from preovulatory follicles of the domestic hen, to metabolize steroid precursors was evaluated. Granulosa and theca interna cells were isolated from ovarian preovulatory follicles at three different developmental stages: F1, F3 and F5. Tritiated pregnenolone (P5), progesterone (P4), dehydroepiandrosterone (DHEA), androstenedione (A4) and testosterone (T) were employed as precursors and their metabolic products were evaluated. The major metabolite of P5 by granulosa cells was P4, but we also observed low amounts of 5β-pregnandione. DHEA metabolism by granulosa cells yielded mainly A4, and minute quantities of 5β-androstan-3,17-dione (5β-dione) were detected. The only significant metabolite obtained in granulosa cells from A4 was 5β-dione, whereas T was only transformed into A4. On the other hand, P5 metabolism by theca interna cells yielded A4 as the main product, also P4, 17α-OHP4, 17α-OHP5, 5β-pregnandione, and DHEA, were found. When DHEA was the precursor A4 was produced in higher amounts than 5β-dione. A4 was mainly transformed into 5β-dione. In similar conditions, T was transformed into A4. These results show that granulosa cells have enzymatic activities of 3β-hydroxysteroid dehydrogenase/5-4 isomerase (3β-HSD from P5 and DHEA), 17β-hydroxysteroid dehydrogenase (17β-HSD from T) and 5β-reductase (from P5, DHEA and A4). Whereas theca interna cells have enzymatic activities of cytochrome P450c17 (from P5 and P4), 3β-HSD (from P5 and DHEA), 17β-HSD (from T) and 5β-reductase (from P4, DHEA and A4). These data support the concept that theca interna cells have the ability to synthesize androgens from progestins produced in granulosa cells. In addition, since theca interna cells did not show the capacity to aromatize androgens suggests that interaction between theca interna and theca externa cells occurs in vivo, thus confirming the three cell model for estrogen production. Furthermore, the fact that other metabolites were produced both in granulosa and theca interna cells, but in a different extent, suggests that complex mechanisms are participating in the regulation of steroid synthesis in avian ovary follicles.     

Reproductive biology of Fopius arisanus (Hymenoptera: Braconidae) on Ceratitis capitata and Anastrepha spp. (Diptera: Tephritidae)

The reproduction of the solitary endoparasitoid Fopius arisanus (Sonan) (Hymenoptera: Braconidae) in Anastrepha ludens (Loew), Anastrepha obliqua (Macquart), and Anastrepha serpentina (Wiedemann) was compared with that using Ceratitis capitata (Wiedemann), being the host in which it had been reared previously. Eggs of different ages (<4 h old, 1, 2, and 3 days old for Anastrepha spp., and ⩽4 h, 1 and 2 days old for C. capitata) of each host species were placed in pieces of papaya, exposed to parasitism for 24 h and then reared through to the adult stage. Host species had a marked effect on parasitoid reproduction with consistently higher parasitoid emergence from C. capitata, whereas emergence from A. obliqua was negligible and this host was not studied further. Host age did not significantly affect parasitoid emergence from C. capitata whereas parasitism of A. ludens and A. serpentina was significantly greater in eggs exposed at 3 days old than those exposed at younger ages. Adult parasitoid sex ratio was male biased in all cases. Despite significant differences in host developmental time, host species did not affect parasitoid developmental time. Parasitoid life expectancy at emergence was reduced by >60% for parasitoids that emerged from A. ludens compared to those that emerged from A. serpentina or C. capitata. The reproduction of parasitoid progeny was highest in parasitoids that emerged from and reproduced on C. capitata and lowest for parasitoids reproducing on A. ludens. Parasitoids that emerged from A. ludens were often deformed, but were larger than those that emerged from A. serpentina. Parasitoids that emerged from C. capitata were smaller than those from Anastrepha spp. We conclude that F. arisanus is capable of sustained reproduction in C. capitata and A. serpentina and merits further study as an agent for the control of these fruit flies.     

Low prevalence of viable Toxoplasma gondii in swine from slaughter houses in the central of China

BackgroundToxoplasma gondii is widely distributed and can infect many species of warm-blooded animals, including swine. This study aimed to evaluate the prevalence of T. gondii in swines from the central of China. A total of 2798 samples, including 305 hearts, 2086 diaphragms, and 407 sera were collected from different swine in Henan Province, China. The modified agglutination test was used to detect antibodies against T. gondii in sera from jugular vein blood and heart blood (cut-off: 1:25), diaphragm juice (cut-off: 1:10). T. gondii DNA was screened from the digestive fluids of all diaphragm tissue samples and seropositive hearts, and attempt to isolate viable T. gondii strain by bioassay in mice.ResultsA total of 9.94% (278/2798) swine tested positive for T. gondii antibodies. Region, but not gender, was associated with T. gondi seropositivity in swine. T. gondii nucleic acid was not found in the tissue digestive fluids (2090 swines). Three groups of mice showed T. gondii antibodies after having been bioassayed with diaphragm samples (n = 81, which came from 2090 swine). No viable T. gondii strain was isolated from muscle of swine.ConclusionsThis is the first large-scale survey T. gondi infection in swine from the central of China. Overall, the prevalence of viable T. gondii in swine was low. Nevertheless, T. gondii infection is present in swine from the central of China. Consumers may acquire T. gondii infection from ingestion of raw or undercooked pork.     

Female sex pheromone components of the cotton bollworm, Heliothis armigera

Detailed examination of abdominal tip extracts from adult female Heliothis armigera revealed the presence of two components which elicit electroantennographic responses from the male moth. These olfactory stimulants have been fully identified as (Z)-11-hexadecenal (I) and (Z)-11-hexadecen-1-ol(II), and detected in airborne volatiles from a ‘calling’ female moth. A third olfactory stimulant was detected only in female tip extracts from some moths of Malawi origin, and this was tentatively identified as (Z)-9-hexadecenal (III). No other olfactory stimulants could be found, although hexadecenal (IV) and 1-hexadecan-1-ol (V) were detected by gas chromatography. In field tests in Malawi, (Z)-11-hexadecenal (I) attracted a few male H. armigera moths to traps but was very much less attractive than the virgin female moth. The attractiveness of (I) was not consistently affected by addition of alcohol (II), aldehydes (III) and (IV), or (E)-11-hexadecenal. Significant numbers of male Earias biplaga moths were found to be attracted to (Z)-11-hexadecenal (I).     

Geographical Distribution and Relative Abundance of Vectors of Scrub Typhus in the Republic of Korea

A survey to determine the geographical distribution and relative abundance of potential vectors of scrub typhus was conducted from October to November 2006 at 13 localities throughout the Republic of Korea. Apodemus agrarius accounted for 97.6% (80/82) of all rodents, while only 2 Myodes regulus (2/82) were collected. A total of 10,860 chiggers were collected from A. agrarius belonging to 4 genera and 8 species, while only Walchia fragilis (40) was collected from Myodes regulus. Leptotrombidium pallidum (8,137; 74.9%), a vector of scrub typhus, was the predominant species collected from A. agrarius followed by Leptotrombidium scutellare (2,057, 18.9%), Leptotrombidium palpale (279; 2.7%), Leptotrombidium orientale (232; 2.1%), and Leptotrombidium zetum (79; 0.7%), Neotrombicula tamiyai (58; 0.5%), Euschoengastica koreaensis (16; 0.1%), and Cheladonta ikaoensis (2; < 0.1%). L. pallidum was the predominant chigger collected at collection sites in Gangwon (100%), Gyeonggi (87.2%), Chungnam (100%), Chungbuk (100%), Jeonbuk (73.9%), Jeonnam (77.0%), and Gyeongbuk (66.1%) provinces, whereas L. scutellare was the predominant chigger collected in Gyeongnam province (77.9%) and Jeju Island (62.3%). Data suggest a correlation between chigger population abundance and human cases of scrub typhus in Korea.     

Mitochondrial DNA variation in Olga Bay larch (Larix olgensis A. Henry) from Primorsky Krai of Russia

Two mitochondrial DNA fragments, nad4(3c-4r) and nad5(1-2r), were sequenced in 58 larch accessions from the range of Larix olgensis A. Henry. Combinations of the nad4 polymorphic sites formed four haplotypes, two of which (H3 and H4) were unique and two (H1, H2) were common. Haplotype H1 was found only in pure L. olgensis from the vicinity of Olga Bay and in a number of accessions from the southern part of the range. Haplotype H2 was detected in the other samples from the range of Olga Bay larch, as well as in hybrid forms. Similarly to the nad4(3c-4r) fragment, the mtDNA fragment UBC460 was able to differentiate larch populations from the range of L. olgensis examined.     

Etiology of Childhood Infectious Diarrhea in a Developed Region of China: Compared to Childhood Diarrhea in a Developing Region and Adult Diarrhea in a Developed Region

In China, great differences in economy, social characteristics and hygiene exist between developing and developed regions. A comparative study of infectious diarrhea between two regions was needed. Three groups of diarrheal patients were collected: children ≤5 year-olds from Beijing (developed region) and Henan Province (developing region), and adults over 18 year-olds from Beijing. A questionnaire was used to survey and feces samples were examined for 16 enteropathogens. We enrolled 1422 children and 1047 adults from developed region and 755 children from developing region. Virus positive rates were 32.98% for children and 23.67% for adults in developed region. The most prevalent pathogen for children was rotavirus whereas for adults was norovirus. Bacterial isolation rates were 13.92% for children from developed region, while 29.14% for children from the developing regions. For the greatest difference, Shigella accounted for 50.79% and was the dominant pathogen in the developing region, whereas in the developed region it was only 1.45%. There was no significant relationship between the local levels of development with diarrheogenic Escherichia coli (DEC) categories. But it was seen the notable differences between the population with different age: enteropathogenic E.coli (EPEC) and enteroaggregative E.coli (EAggEC) were the primary classes of DEC in children from both regions, whereas it was enterotoxigenic E.coli (ETEC) in adults. The symptoms of Shigella and Salmonella infection, such as bloody stools, white blood cells (WBC) and red blood cells (RBC) positivity and fever were similar in children, which may lead to the misidentification. Yersinia enterocolitica and shiga toxin-producing E.coli (STEC) infections were firstly reported in Beijing. There was a large difference in etiology of bacterial diarrhea between children in developing and developed regions of China.     

Molecular Structure and Transferability of Tn1546-Like Elements in Enterococcus faecium Isolates from Clinical, Sewage, and Surface Water Samples in Iran

The molecular structure and transferability of Tn1546 in 143 vancomycin-resistant Enterococcus faecium (VREF) isolates obtained from patients (n = 49), surface water (n = 28), and urban and hospital sewage (n = 66) in Tehran, Iran, were investigated. Molecular characterization of Tn1546 elements in vanA VREF was performed using a combination of restriction fragment length polymorphism analysis and DNA sequencing of the internal PCR fragments of vanA transposons. Long-PCR amplification showed that the molecular size of Tn1546 elements varied from 10.8 to 12.8 kb. The molecular analysis of Tn1546 showed that 45 isolates (31.5%) harbored a deletion/mutation upstream from nucleotide 170. No horizontal transfer of Tn1546 was observed following filter-mating conjugation with these isolates. Nevertheless, the rates of transferability for other isolates were 10⁻⁵ to 10⁻⁶ per donor. Insertion sequences IS1216V and IS1542 were present in 103 (72%) and 138 (96.5%) of the isolates, respectively. The molecular analysis of Tn1546 elements resulted in three genomic organizations. The genomic organization lineage 1 was dominated by the isolates from clinical samples (3.4%), lineage 2 was dominated mostly by sewage isolates (24.5%), and lineage 3 contained isolates obtained from all sources (72.1%). The genetic diversity determined using pulsed-field gel electrophoresis (PFGE) revealed a single E. faecium clone, designated 44, which was common to the samples obtained from clinical specimens and hospital and municipal sewage. Furthermore, the results suggest that lineage 3 Tn1546 was highly disseminated among our enterococcal isolates in different PFGE patterns.