Repetitive Element PCR Research Articles

Occurrence of Staphylococcus aureus in cattle, sheep, goat, and pig rearing in the Czech Republic

The study focused on the prevalence ofStaphylococcus aureusand resistant strains in livestock. In this study, 114 different samples from three cattle farms (84 from two farms of dairy cows and 30 from one farm of suckler cows), 132 samples from one sheep farm, 120 samples from one goat farm, and 82 samples from three pig farms were examined. Strains identified asStaphylococcus aureuswere further analysed by the polymerase chain reaction method for detection of themecA gene and for confirmation of the sequence type 398. Positive incidence ofStaphylococcus aureuswas confirmed in farms of suckler cows, sheep, goats and pigs. The incidence of methicilin-resistantStaphylococcus aureuswas confirmed at a goat farm, with all strains belonging to the sequence type 398. Repetitive element palindromic-polymerase chain reaction analysis was performed to compare the relatedness of selected human and animalS. aureusstrains at the goat and sheep farms. The obtained data from repetitive element-polymerase chain reaction analysis showed significant clonal similarity among the tested isolates and indicated the possibility of mutual transmission between animals or animal and human and possible transfer in the food chain.

Morphological and Genetic Diversity of Rhizobia Nodulating Cowpea (Vigna unguiculata L.) from Agricultural Soils of Lower Eastern Kenya.

Limited nitrogen (N) content in the soil is a major challenge to sustainable and high crop production in many developing countries. The nitrogen fixing symbiosis of legumes with rhizobia plays an important role in supplying sufficient N for legumes and subsequent nonleguminous crops. To identify rhizobia strains which are suitable for bioinoculant production, characterization of rhizobia is a prerequisite. The objective of this study was to assess the morphological and genetic diversity of rhizobia that nodulates cowpea in agricultural soils of lower eastern Kenya. Twenty-eight rhizobia isolates were recovered from soil samples collected from farmers' fields in Machakos, Makueni, and Kitui counties in lower eastern Kenya and characterized based on morphological characteristics. Thirteen representative isolates were selected and characterized using BOX repetitive element PCR fingerprinting. Based on the dendrogram generated from morphological characteristics, the test isolates were distributed into two major clusters at a similarity of 75%. Phylogenetic tree, based on BOX repetitive element PCR, grouped the isolates into two clusters at 90% similarity level. The clustering of the isolates did not show a relationship to the origin of soil samples, although the isolates were genetically diverse. This study is a prerequisite to the selection of suitable cowpea rhizobia to develop bioinoculants for sustainable crop production in Kenya.

Detection of Salmonella enterica Serovar Montevideo and Newport in Free‐ranging Sea Turtles and Beach Sand in the Caribbean and Persistence in Sand and Seawater Microcosms

Salmonellae are Gram-negative zoonotic bacteria that are frequently part of the normal reptilian gastrointestinal flora. The main objective of this project was to estimate the prevalence of non-typhoidal Salmonella enterica in the nesting and foraging populations of sea turtles on St. Kitts and in sand from known nesting beaches. Results suggest a higher prevalence of Salmonella in nesting leatherback sea turtles compared with foraging green and hawksbill sea turtles. Salmonella was cultured from 2/9 and identified by molecular diagnostic methods in 3/9 leatherback sea turtle samples. Salmonella DNA was detected in one hawksbill turtle, but viable isolates were not recovered from any hawksbill sea turtles. No Salmonella was detected in green sea turtles. In samples collected from nesting beaches, Salmonella was only recovered from a single dry sand sample. All recovered isolates were positive for the wzx gene, consistent with the O:7 serogroup. Further serotyping characterized serovars Montevideo and Newport present in cloacal and sand samples. Repetitive-element palindromic PCR (rep-PCR) fingerprint analysis and pulsed-field gel electrophoresis of the 2014 isolates from turtles and sand as well as archived Salmonella isolates recovered from leatherback sea turtles in 2012 and 2013, identified two distinct genotypes and four different pulsotypes, respectively. The genotyping and serotyping were directly correlated. To determine the persistence of representative strains of each serotype/genotype in these environments, laboratory-controlled microcosm studies were performed in water and sand (dry and wet) incubated at 25 or 35°C. Isolates persisted for at least 32days in most microcosms, although there were significant decreases in culturable bacteria in several microcosms, with the greatest reduction in dry sand incubated at 35°C. This information provides a better understanding of the epizootiology of Salmonella in free-ranging marine reptiles and the potential public health risks associated with human interactions with these animals in the Caribbean.

Antibiotic resistance and repetitive-element PCR fingerprinting in Aeromonas veronii isolates.

This study evaluated antibiotic resistance and the related genes in total 47 Aeromonas veronii isolates from pet fish, eel (Anguilla japonica) and koi (Cyprinus carpio) in Korea. In comparison with the antibiotic susceptibilities of isolates from eel and koi, those of pet fish were more resistant to ceftiofur, aminoglycosides, tetracycline and nitrofurantoin. And isolates from pet fish showed high prevalences of class 1 integron, quinolones and tetracycline resistance determinants than those from eel and koi. Repetitive-element palindromic PCR (rep-PCR) showed larger diversities among A.veronii isolates. Collectively, pet fish may be a reservoir for multiple clones of A.veronii involved in antibiotic resistance. In this aspect, imported fish in the aquaculture trade should be steadily and continually screened for bacterial antibiotic resistance and related genes.

Clostridium difficile: A rare cause of pyogenic liver abscess

Extra-intestinal infections due to Clostridium difficile have been reported rarely. Herein we report a case of pyogenic liver abscess from toxigenic C. difficile in an 80-year-old non-hospitalized woman with diabetes mellitus, cerebrovascular and cardiovascular diseases. The patient was admitted to the emergency department with fever and abdominal pain. There was no history of diarrhea or use of antibiotics. Laboratory parameters revealed signs of inflammation and elevated AST and ALT levels. Abdominal ultrasound and computer tomography showed multiple focal lesions in the bilateral liver lobes and hydropic gallbladder with stones. The patient underwent cholecystectomy and the liver abscesses were drained. Toxigenic C. difficile strains were isolated from the drained pus and also from the stool sample. According to repetitive-element PCR (rep-PCR) analyses both organisms were the same. The organisms were susceptible to antibiotics. Despite proper antibiotic therapy and surgical drainage, the patient succumbed to her illness.

Prevalence of Major Methicillin-Resistant Staphylococcus aureus Clones in Korea Between 2001 and 2008.

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) are important pathogens causing nosocomial infections in Korean hospitals. This study aimed to investigate the epidemiological and genetic diversity of clinical S. aureus isolates in healthcare settings from 2001 to 2008.MethodsSamples and data were obtained from 986 individuals as part of the National Antimicrobial Surveillance Project, involving 10 regions nationwide. Molecular typing studies, including multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing were performed, and a representative clone of Korean MRSA was classified by combinational grouping using a DiversiLab (DL; bioMérieux, France) repetitive element polymerase chain reaction (rep-PCR) system.ResultsNine Korean MRSA clones (KMRSA-1 to -9) were identified by analysis of genetic backgrounds and molecular characteristics. KMRSA-1 to -3, expressing clonal complex (CC) 5 (carrying SCCmec II), CC8 (carrying SCCmec III), and CC72 (carrying SCCmec IV) were spread nationwide. In contrast, KMRSA-6 was highly prevalent in Gyeongsangnam-do, and KMRSA-4 was highly prevalent in Jeollanam-do and Jeollabuk-do.ConclusionsEpidemic KMRSA clones were genetically similar to major clones identified from the USA, with the exception of KMRSA-2, which had the SCCmec III type. Our results provide important insights into the distribution and molecular genetics of MRSA strains in Korea and may aid in the monitoring of MRSA spread throughout the country.

Genotypic and Pathotypic Diversity of Xanthomonas oryzae pv. oryzae Strains in Taiwan

AbstractRice bacterial leaf blight, caused by Xanthomonas oryzae pv. oryzae [(Ishiyama) Swings et al. 1990] (Xoo), is a major rice disease of the second crop season in Taiwan. A total of 88 Xoo strains collected from 10 major rice cultivating areas in Taiwan from 1986, 1997, 2000, 2004, and 2011 were characterized by repetitive‐element PCR (REP‐PCR) fingerprinting and virulence analyses. Among the five genetic clusters identified by the pJEL1/pJEL2 (IS1112‐based) and REP1R‐Dt/REP2‐D [repetitive extragenic palindromic (REP)‐based] primer sets, clusters A, C and D contained Xoo strains from geographically distant regions, which suggests a high frequency of Xoo dispersal in Taiwan. The 88 Xoo strains were evaluated by inoculations on IRBB near‐isogenic lines and five Taiwan rice cultivars. A subset of 45 moderately or highly virulent strains were classified into 15 pathotypes by their compatible or incompatible reactions on IR24 and 12 IRBB near‐isogenic lines, each containing a single resistance gene. Analysis of molecular haplotypes and pathotypes revealed a partial relationship. IRBB5, IRBB21 and IRBB4 were incompatible with 96%, 96% and 73% of the strains, so xa5, Xa21 and Xa4 can recognize most of the Xoo strains in Taiwan and elicit resistance. In contrast, IRBB3 (Xa3), IRBB8 (xa8), IRBB10 (Xa10), IRBB11 (Xa11), IRBB13 (xa13) and IRBB14 (Xa14) were susceptible to almost all of the 45 Xoo strains. Inoculation trials revealed significant differences in the susceptibility of five Taiwan cultivars to Xoo (from high to low susceptibility: Taichung Sen 10 > IR24, Taichung Native 1 > Taichung 192, Taikeng 9, Tainan 11). This study provides useful information for resistance breeding and the development of disease management strategies against bacterial blight disease of rice.

Extended-spectrum beta-lactamase--producing enterobacteriaceae in the intensive care unit: acquisition does not mean cross-transmission.

BackgroundIn intensive care unit (ICU), infection and colonization by resistant Gram-negative bacteria increase costs, length of stay and mortality. Extended-spectrum beta-lactamase − producing Enterobacteriaceae (ESBL-E) is a group of pathogens increasingly encountered in ICU setting. Conditions that promote ESBL-E acquisition are not completely understood. The increasing incidence of infections related to ESBL-E and the unsolved issues related to ESBL-E cross-transmission, prompted us to assess the rates of referred and acquired cases of ESBL-E in ICU and to assess patient-to-patient cross-transmission of ESBL-E using a multimodal microbiological analysis.MethodsDuring a 5-month period, all patients admitted to a medical ICU were tested for ESBL-E carriage. A rectal swab was performed at admission and then twice a week until discharge or death. ESBL-E strains were analyzed according to antibiotic susceptibility pattern, rep-PCR (repetitive-element Polymerase chain reaction) chromosomal analysis, and plasmid PCR (Polymerase chain reaction) analysis of ESBL genes. Patient-to-patient transmission was deemed likely when 2 identical strains were found in 2 patients hospitalized simultaneously in the ICU.ResultsAmong the 309 patients assessed for ESBL-E carriage on admission, 25 were found to carry ESBL-E (importation rate: 8 %). During follow-up, acquisition was observed among 19 of them (acquisition rate: 6.5 %). Using the multimodal microbiological approach, we found only one case of likely patient-to-patient ESBL-E transmission.ConclusionsIn unselected ICU patients, we found rather low rates of ESBL-E referred and acquired cases. Only 5 % of acquisitions appeared to be related to patient-to-patient transmission. These data highlight the importance of jointly analyzing phenotypic profile and molecular data to discriminate strains of ESBL-E.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-1489-z) contains supplementary material, which is available to authorized users.

Diversity of Xanthomonas campestris Isolates from Symptomatic Crucifers in New York State.

To assess the diversity of Xanthomonas campestris spp. infecting crucifers in New York, 154 isolates were collected over 10 years across the state. The goal was to determine if isolates of the pathogen were overwintering in New York and serving as primary inoculum in subsequent years, or if novel isolates were entering the state each year. Pure cultures of isolates were characterized using multilocus sequence analysis (MLSA), a greenhouse pathogenicity assay, repetitive element-polymerase chain reaction (Rep-PCR) using the BOX-A1R primer, and enzyme-linked immunosorbent assay. The MLSA scheme proved to be more efficient than Rep-PCR for a large sample population and for comparison with global isolates. X. campestris isolated from crucifers in New York comprised of X. campestris pv. campestris and X. campestris pv. raphani, with X. campestris pv. raphani being predominately isolated from transplants. Evidence for unique haplotypes persisting on the same farm for several years due to improper seedbed rotations was documented in addition to novel haplotypes being spread throughout states through infected transplants and seed. Rep-PCR confirmed the high diversity of X. campestris and was used to generate 15 unique fingerprint patterns from isolates collected in the first 5 years. A worldwide comparison of isolates suggests that the X. campestris pv. campestris population appears to be very homogenous with dominant haplotypes persisting for extended periods and being globally disseminated.

Existence of Paenibacillus larvae genotypes ERIC I-ST2, ERIC I-ST15 and ERIC II-ST10 in the western region of Aichi prefecture, Japan.

American foulbrood is the most destructive honeybee bacterial disease. The etiological agent, Paenibacillus larvae, has been classified into four genotypes by a repetitive-element PCR (ERIC I-IV) and 21 sequence types by multilocus sequence typing (ST1-21). In this study, we genotyped Japanese P. larvae isolates for the first time and revealed the presence of three genotypes (ERIC I-ST2, ERIC I-ST15 and ERIC II-ST10) in the western region of Aichi prefecture. ERIC I-ST15 and ERIC II-ST10 are globally distributed types, whereas the ERIC I-ST2 isolate was the first isolate of this genotype identified outside the native range of the European honeybee. The ERIC I and II isolates differed in phenotypes including cell morphology, and these may be useful for predicting ERIC types.

Endophytic Bacteria Isolated from Common Bean (Phaseolus vulgaris) Exhibiting High Variability Showed Antimicrobial Activity and Quorum Sensing Inhibition.

Endophytic bacteria play a key role in the biocontrol of phytopathogenic microorganisms. In this study, genotypic diversity was analyzed via repetitive element PCR (rep-PCR) of endophytic isolates of the phylum Actinobacteria that were previously collected from leaves of cultivars of common bean (Phaseolus vulgaris). Considerable variability was observed, which has not been reported previously for this phylum of endophytic bacteria of the common bean. Furthermore, the ethanol extracts from cultures of various isolates inhibited the growth of pathogenic bacteria in vitro, especially Gram-positive pathogens. Extracts from cultures of Microbacterium testaceum BAC1065 and BAC1093, which were both isolated from the 'Talismã' cultivar, strongly inhibited most of the pathogenic bacteria tested. Bean endophytic bacteria were also demonstrated to have the potential to inhibit the quorum sensing of Gram-negative bacteria. This mechanism may regulate the production of virulence factors in pathogens. The ability to inhibit quorum sensing has also not been reported previously for endophytic microorganisms of P. vulgaris. Furthermore, M. testaceum with capacity to inhibit quorum sensing appears to be widespread in common bean. The genomic profiles of M. testaceum were also analyzed via pulsed-field gel electrophoresis, and greater differentiation was observed using this method than rep-PCR; in general, no groups were formed based on the cultivar of origin. This study showed for the first time that endophytic bacteria from common bean plants exhibit high variability and may be useful for the development of strategies for the biological control of diseases in this important legume plant.

Molecular characterization of Acidithiobacillus ferrooxidans strains isolated from different environments by three PCR-based methods

PCR-based DNA fingerprinting, REP-PCR (repetitive element PCR), RAPD (randomly amplified polymorphic DNA) and 16S rDNA sequence analyses were used to characterize 23 Acidithiobacillus ferrooxidans strains isolated from different environments. (GTG)5 and BOXA1R primer were selected for REP-PCR. Twenty arbitrary primers were used for RAPD to acquire DNA profiles from A. ferrooxidans. Both RAPD and REP-PCR produce complex banding patterns and show good discriminatory ability in differentiating closely related strains of A. ferrooxidans. The strains are clustered into 4 or 5 major groups and reveal genomic diversity using (GTG)5-PCR, BOX-PCR and RAPD analysis. Phylogenetic tree based on 16S rDNA sequences of 23 strains and related strains shows that they are clustered into two distinct groups. Twelve strains are highly related to a new Acidithiobacillus named Acidithiobacillus ferrivorans. The results indicate that PCR-based methods are effective in revealing genetic diversity among A. ferrooxidans.

Molecular typing and differentiation of Mycobacterium tuberculosis clinical isolates using Double Repetitive Element PCR and Duplex PCR

BackgroundTo date, the advancements in polymerase chain reaction (PCR) assures accurate, fast identification and mycobacterial speciation in clinical settings, which promotes a better tuberculosis (TB) treatment regimen. MethodsIn this study, a total of 78 clinically suspected cases of TB were processed for the detection of Mycobacterial infections by standard Ziehl Neelsen (ZN) staining, conventional Lowenstein–Jensen (LJ) and BACTEC MGIT-960™ liquid culture. Strain typing was performed by using Double Repetitive Element PCR (DRE-PCR) and Duplex PCR (DPCR) to differentiate Mycobacteriumtuberculosis complex (MTB) from non-tuberculous mycobacteria (NTM), respectively. ResultsOf 78 clinical isolates, 25 (32%) were drug-susceptible, and 53 (68%) were resistant to at least one drug. The BACTEC MGIT-960™ showed the highest (88.5%) positivity rate, compared with conventional LJ (82%) and ZN smear (61.5%). The mean time detection and drug susceptibility for MTB was 28 and 40days in LJ culture, and 10 and 13days in BACTEC MGIT-960™ culture. Using DPCR, Mycobacteriumavium infection was identified in HIV-positive (2.56%) and MTB in HIV-negative patients (97.4%), and the DRE-PCR system divulged 15 unique genotype patterns, and an institutional-based epidemiology database was created. ConclusionsThe combination of an in-house DRE–DPCR system could possibly identify and differentiate MTB from other mycobacterial species in a single reaction. In addition, restriction polymorphism analysis and DNA sequencing of NTM could assist in species identification directly from clinical isolates.

In vitro Antimicrobial Comparison of Taif and Egyptian Pomegranate Peels and Seeds Extracts

Punica granatum are utilized by local people as the part of their meal. Peoples supposed to consume Punica granatum seed and their peel was thrown as waste. Present study was designed to evaluate the antibacterial activity of the DMSO, ethanol and methanol extracts of Egyptian and Taif cultivars of Punica granatum peel and seeds extracts against five opportunistic pathogens namely Staphylococcus aureus, Pseudomonas sp. and Bacillus sp. (as a gram positive bacteria) and Escherichia coli and Aeromonas hydrophila (as a gram negative bacteria). The antimicrobial activity of plant peels and seeds extracts were compared with that of Streptomycin, as reference antibiotics. Evaluations were based on the zone of inhibition using agar well diffusion assay. The inhibitory activity was found to be dose dependent. The methanol extract of the peels from the two cultivars at 15 mg/ml dosage were found to be active antimicrobials against all the test microorganisms. While, the maximum antimicrobial activity for the seeds extracts were reported at 60 mg/ml. Escherichia coli was reported to have significant susceptibility against most of the extract followed by Staphylococcus aureus and Pseudomonas sp. Additionally, we evaluated the effect of the peels and seeds extract on the DNA damage of the bacterial genome using the repetitive element PCR analysis technique (Rep-PCR). The Rep-PCR results significantly showed that there are a polymorphic numbers of genetic bands, which were found in E. coli treated bacteria and absent in the untreated bacteria. This study indicates that aqueous DMSO, methanol and ethanol extracts of peels and seeds of the two cultivars of Punica granatum may be utilizes as a potential source of antimicrobial and mutagen agents.

Phenotypic and genotypic heterogeneity among Streptococcus iniae isolates recovered from cultured and wild fish in North America, Central America and the Caribbean islands.

Streptococcus iniae, the etiological agent of streptococcosis in fish, is an important pathogen of cultured and wild fish worldwide. During the last decade outbreaks of streptococcosis have occurred in a wide range of cultured and wild fish in the Americas and Caribbean islands. To gain a better understanding of the epizootiology of S. iniae in the western hemisphere, over 30 S. iniae isolates recovered from different fish species and geographic locations were characterized phenotypically and genetically. Species identities were determined biochemically and confirmed by amplification and sequencing of the 16S rRNA gene. Repetitive-element palindromic PCR fingerprinting as well as biochemical and antimicrobial susceptibility profiles suggest that a single strain of S. iniae was responsible for two different disease outbreaks among reef fishes in the Caribbean, one in 1999 and another in 2008. Interestingly, a majority of the isolates recovered from cultured fish in the Americas were genetically distinct from the Caribbean isolates and exhibited a trend toward higher minimal inhibitory concentration with respect to several antibiotics as well as greater genetic variability. The biological significance of this genetic variability is unclear, but it could have implications for future vaccine development and treatment.

Phylogenetic and genetic characterization of Acidithiobacillus strains isolated from different environments.

To study the phylogenetic relationships and genetic heterogeneity of 21 Acidithiobacillus strains isolated from different environments, we amplified and sequenced the 16S-23S rRNA gene intergenic spacers (ITS) of all these strains. These sequence data, combined with related sequences available from GenBank, were divided into six phylogenetic groups by 16S rRNA gene and by 16S-23S rRNA gene sequence analysis. The results of phylogenetic analysis were consistent with those obtained by repetitive element PCR and arbitrarily primed PCR. In this research, the Acidithiobacillus ferrooxidans (A. ferrooxidans) strains were always separated into two groups in phylogenetic and cluster analyses. Genotypic analyses of the genes rusA, rusB, hip and iro suggest that these two groups may have different biochemical mechanisms for oxidizing ferrous iron. Strains in one A. ferrooxidans group were detected with rusA gene that encodes rusticyanin A which plays a very important role in the iron respiratory chain. The second A. ferrooxidans group was found to contain rusB gene which encode a homologous protein (RusB). The data suggested that ITS-based phylogeny is an effective tool to elucidate the relationships of Acidithiobacillus and that a different iron oxidation pathway may exist in different A. ferrooxidans groups.

Rhizobia Indigenous to the Okavango Region in Sub-Saharan Africa: Diversity, Adaptations, and Host Specificity

The rhizobial community indigenous to the Okavango region has not yet been characterized. The isolation of indigenous rhizobia can provide a basis for the formulation of a rhizobial inoculant. Moreover, their identification and characterization contribute to the general understanding of species distribution and ecology. Isolates were obtained from nodules of local varieties of the pulses cowpea, Bambara groundnut, peanut, hyacinth bean, and common bean. Ninety-one of them were identified by BOX repetitive element PCR (BOX-PCR) and sequence analyses of the 16S-23S rRNA internally transcribed spacer (ITS) and the recA, glnII, rpoB, and nifH genes. A striking geographical distribution was observed. Bradyrhizobium pachyrhizi dominated at sampling sites in Angola which were characterized by acid soils and a semihumid climate. Isolates from the semiarid sampling sites in Namibia were more diverse, with most of them being related to Bradyrhizobium yuanmingense and Bradyrhizobium daqingense. Host plant specificity was observed only for hyacinth bean, which was nodulated by rhizobia presumably representing yet-undescribed species. Furthermore, the isolates were characterized with respect to their adaptation to high temperatures, drought, and local host plants. The adaptation experiments revealed that the Namibian isolates shared an exceptionally high temperature tolerance, but none of the isolates showed considerable adaptation to drought. Moreover, the isolates' performance on different local hosts showed variable results, with most Namibian isolates inducing better nodulation on peanut and hyacinth bean than the Angolan strains. The local predominance of distinct genotypes implies that indigenous strains may exhibit a better performance in inoculant formulations.

Isolation and characterization of putative endophytic bacteria antagonistic to Phoma tracheiphila and Verticillium albo-atrum.

A collection of 200 bacterial isolates recovered from citrus plants (Citrus limon, Citrus sinensis, and Citrus reticulata), Medicago truncatula and Laurus nobilis, was established. In vitro screening indicated that 28 isolates exhibited an inhibitory activity against the vascular pathogens Phoma tracheiphila and Verticillium albo-atrum. Isolates were screened according to their hydrolytic activities, plant growth-promoting bacteria (PGPB) abilities, as well as for the presence of nonribosomal peptide synthetase (NRPS) genes responsible of the lipopeptide biosynthesis. The results were positive for 16 isolates which exhibited at least two PGPB activities and a single NRPS gene. Genetic diversity of the selected isolates was studied using random amplified polymorphic DNA (RAPD) and repetitive element PCR (REP) tools that showed clustering of strains into three major groups (I, II, and III) (i, ii, and iii), respectively. Clustering was further confirmed by the 16S rDNA sequencing that assigned nine isolates to Bacillus velezensis, four isolates to Bacillus methyltrophicus, one isolate to Bacillus amyloliquefaciens, and two isolates to Bacillus mojavensis. Organ-bacterial genotype interaction as well as positive correlation with NRPS genes are discussed.

Repetitive-Element PCR Technology for Identification of Mulberry Pathogens

The coronatine is a new-type and high-efficient biogenic chlorosis-inducing phytotoxin. It’s also a new potential chemical regulator. Plants can get higher stress and disease resistance with spraying coronatine at a low concentration, which has broad application prospects. It’s an effective way to ferment coronatine industrially using Pseudomonas syringae. The REP universal primers were used to establish the repetitive sequence PCR technology. Clustering analysis and classification were used to screen the wild strains producing coronatine from Jiangsu and Zhejiang area. The results showed that 29 strains were divided into five groups with similarity coefficient of 0.65. The cluster analysis showed the highest diversity of P. syringae pv. mori appeared in mulberry organization form Chun-An, which is relevant with the regional water conditions. It provides a new thought to screen the wild strains producing coronatine.

Evaluation of repetitive element polymerase chain reaction for surveillance of methicillin-resistant Staphylococcus aureus at a large academic medical center and community hospitals

Repetitive element polymerase chain reaction (rep-PCR) typing has been used for methicillin-resistant Staphylococcus aureus (MRSA) strain characterization. The goal of this study was to determine if a rapid commercial rep-PCR system, DiversiLab™ (DL; bioMérieux, Durham, NC, USA), could be used for MRSA surveillance at a large medical center and community hospitals. A total of 1286 MRSA isolates genotyped by the DL system were distributed into 84 distinct rep-PCR patterns: 737/1286 (57%) were clustered into 6 major rep-PCR patterns. A subset of 220 isolates was further typed by pulsed-field gel electrophoresis (PFGE), spa typing, and SCCmec typing. The 220 isolates were distributed into 80 rep-PCR patterns, 94 PFGE pulsotypes, 27 spa, and 3 SCCmec types. The DL rep-PCR system is sufficient for surveillance, but the DL system alone cannot be used to compare data to other institutions until a standardized nomenclature is established and the DL MRSA reference library is expanded.