Polymorphic microsatellite markers for the endangered fish, the slender shiner Pseudopungtungia tenuicorpa and cross-species amplification across five related species.

The slender shiner Pseudopungtungia tenuicorpa (Cypriniformes; Cyprinidae; Gobioninae) is an endangered freshwater fish species endemic to Korea. The current strategies for its conservation involve the study of population genetic characters and identification of management units. These strategies require suitable molecular markers to study genetic diversity and genetic structure. Here, we developed nine polymorphic microsatellite markers for P. tenuicorpa for the first time by applying an enrichment method from a size-selected genomic library. The developed microsatellite markers produced a total of 101 alleles (average 11.2). The observed and expected heterozygosities averaged 0.805 and 0.835, respectively. Among the nine identified markers, five markers showed successful amplification across five related Korean Gobioninae species. Thus, the microsatellite markers developed in this study will be useful to establish conservation strategies for both P. tenuicorpa and other related species.

Association between BMP-2 and COL6A1 gene polymorphisms with susceptibility to ossification of the posterior longitudinal ligament of the cervical spine in Korean patients and family members.

COL6A1 and BMP-2 genes have been implicated in ossification of the posterior longitudinal ligament (OPLL) susceptibility in Japanese and Chinese Han populations. However, no study has yet investigated the DNA of unaffected family members of patients with OPLL. This study investigated differences in genetic polymorphisms of BMP-2 and COL6A1 between Korean patients with OPLL and their family members (with and without OPLL). A total of 321 subjects (110 patients with OPLL and 211 family members) were enrolled in the study. Associations between two single nucleotide polymorphisms (SNPs) of the BMP-2 gene (Ser37Ala and Ser87Ser) and two SNPs of COL6A1 [promoter (-572) and intron 33 (+20)] with susceptibility to OPLL of the cervical spine were investigated between the two groups (OPLL+ and OPLL-). Of the 321 subjects, 162 had cervical OPLL (50.4%; 110 patients, 52 family members). There was a familial tendency of OPLL in 34 of the 110 families (30.9%). Allele and haplotype frequencies of the four SNPs in the BMP-2 and COL6A1 genes did not differ significantly between the OPLL+ and OPLL- groups, even when excluding participants over 50 years of age. This is the first report identifying SNPs of COL6A1 and BMP-2 in Korean patients and family members with OPLL. Although allele and haplotype frequencies were similar with those of a previous study in Japanese and Chinese patients, unaffected family members also showed similar rates of these SNPs in the present study. These results suggest that these SNPs may not directly influence the expression of OPLL.

Pathotypes and genetic relationship of worldwide collections of Elsinoë spp. causing scab diseases of citrus.

Two scab diseases are recognized currently on citrus: citrus scab, caused by Elsinoë fawcettii, and sweet orange scab, caused by E. australis. Because the two species cannot be reliably distinguished by morphological or cultural characteristics, host range and molecular methods must be used to identify isolates. Four pathotypes of E. fawcettii and two of E. australis have been described to date based on host range. The host specificity and genetic relationships among 76 isolates from Argentina, Australia, Brazil, Korea, New Zealand, and the United States were investigated. Based on pathogenicity tests on eight differential hosts, 61 isolates were identified as E. fawcettii and 15 as E. australis. Of 61 isolates of E. fawcettii, 24 isolates were identified as the Florida broad host range (FBHR) pathotype, 7 as the Florida narrow host range (FNHR) pathotype, 10 as the Tryon's pathotype, and 3 as the "Lemon" pathotype. Two new pathotypes, the "Jingeul" and the satsuma, rough lemon, grape-fruit, clementine (SRGC), are described, and four isolates did not fit into any of the known pathotypes of E. fawcettii. Of the 15 isolates of E. australis from Argentina and Brazil, 9 belonged to the sweet orange pathotype and 6 from Korea to the natsudaidai pathotype. E. fawcettii and E. australis were clearly distinguishable among groups by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) assays and the E. fawcettii group was divided into three subgroups, A-1, A-2, and A-3. The A-1 group was composed of the FBHR, FNHR, and SRGC pathotypes; some Lemon pathotypes; and the uncertain isolates. The A-2 subgroup included all of the Tryon's pathotype isolates and one of the three Lemon pathotype isolates and the A-3 group contained the Jingeul pathotype isolates. E. australis was differentiated into two groups: B-1, the natsudaidai pathotype isolates, and B-2, the sweet orange pathotype isolates. Isolates of E. fawcettii and E. australis were clearly distinguishable by sequence analysis of the internal transcribed spacer (ITS) region and the translation elongation factor 1 alpha (TEF) gene. There were also fixed nucleotide differences in the ITS and TEF genes that distinguished subgroups separated by RAPD-PCR within species. We confirmed two species of Elsinoë, two pathotypes of E. australis, and at least six pathotypes of E. fawcettii and described their distribution in the countries included in this study.

Genetic structuring of boll weevil populations in the US based on RAPD markers.

Abstract Randomly amplified polymorphic DNA (RAPD) analysis was performed to infer the magnitude and pattern of genetic differentiation among boll weevil populations from eighteen locations across eight US states and north-east Mexico. Sixty-seven reproducible bands from six random primers were analysed for genetic variation within and between weevil populations. Genetic and geographical distances among all populations were positively correlated, reflecting a pattern of isolation by distance within a larger metapopulation. Gene flow between south-central, western and eastern regions is limited, but migration between locations within regions appears to be relatively frequent up to distances of approximately 300-400 km. However, estimates of effective migration were much lower than those estimated from mtDNA-RFLP data reported previously.

Children hospitalized for varicella: a prevaccine review.

OBJECTIVES: To describe varicella complications in healthy and previously ill children hospitalized for varicella and to explore trends in group A beta-hemolytic streptococcus complications of varicella. METHODS: A retrospective record review of children hospitalized for varicella between January 1, 1990, and March 31, 1994, was conducted in nine large acute care hospitals in Los Angeles County, California. RESULTS: We identified 574 children hospitalized for varicella in study hospitals during the 4.25-year study period (estimated risk of hospitalization, approximately 1 in 550 cases of varicella); 53% of the children were healthy before the onset of varicella and 47% were previously ill with underlying cancers or other chronic illnesses. Children were hospitalized for treatment of complications (n = 427, 74%) or for prophylactic antiviral therapy or observation (n = 147, 26%). Systems involved in complications included skin/soft tissue (45%), neurologic (18%), respiratory (14%), gastrointestinal (10%), and hematologic, renal, or hepatic (8% or less). The mean age of children with skin/soft tissue infections was 2.7 years (range < 1 to 16 years) compared with 4.7 years (< 1 to 18 years) for other complications. Children with skin/soft tissue and neurologic complications were more often previously healthy (p < 0.05), whereas those with respiratory complications were more often previously ill (p < 0.001). Hospitalizations for skin/soft tissue infections increased during the study period. The proportion of complications as a result of group A beta-hemolytic streptococcus infection increased from 4.7% before 1993 to 12.2% for the remainder of the study period (p = 0.02). CONCLUSIONS: Prior health status was predictive of the type of complications experienced by children with varicella requiring hospitalization. Our data suggest a recent increase in skin/soft tissue complications of varicella requiring hospitalization and an increase in the proportion of complications related to group A beta-hemolytic streptococcus. Wide-scale vaccine use should reverse this trend and reduce the overall impact of varicella on both healthy and previously ill children.

Efficacy of beta-lactamase-resistant penicillin and influence of penicillin tolerance in eradicating streptococci from the pharynx after failure of penicillin therapy for group A streptococcal pharyngitis.

We studied the ability of dicloxacillin, a beta-lactamase-resistant penicillin, to eradicate persistent group A streptococci from the upper respiratory tract of children previously given penicillin V, and concomitantly assessed the role of antibiotic (penicillin and dicloxacillin) tolerance as a contributing factor. During a group A streptococcal pharyngitis outbreak, 66% of 324 children were found to be culture positive for group A streptococci. Ninety percent of these isolates were serotype M-1, T-agglutination pattern T-1. The treatment failure rate after initial orally administered penicillin treatment was 21% (42 of 204). These 42 children then received either a second course of penicillin V orally or a course of dicloxacillin. The resulting rates of failure to eradicate the homologous streptococcal serotype were 83% (20 of 24) and 50% (9 of 18), respectively (P less than 0.02). Of 189 streptococcal isolates tested by the gradient replicate plate method for penicillin tolerance, 18 (10%) were tolerant. In this study, penicillin-tolerant strains of group A streptococci were no more frequently isolated from children in whom initial penicillin treatment failed than from those who were successfully treated. Dicloxacillin tolerance was not a factor in failure of dicloxacillin therapy. These data, when evaluated with data from previous studies, suggest that reasons for failure to eradicate group A streptococci from the upper respiratory tract are complex, but dicloxacillin may be beneficial in some patients who fail to respond to orally administered penicillin therapy.

Association of penicillin tolerance with failure to eradicate group A streptococci from patients with pharyngitis.

Despite uniform susceptibility of group A streptococci to penicillin, failure to eradicate group A streptococci is not uncommon in patients receiving penicillin for treatment of pharyngitis. We explored the possibility that penicillin tolerance could explain this phenomenon. We examined 48 group A streptococcal isolates from 48 patients successfully treated with penicillin (streptococci eradicated) and 92 isolates from 37 patients (one to four isolates per patient) who failed to respond to penicillin therapy (streptococci not eradicated). Penicillin tolerance was recognized by the gradient-replicate plate method and by time-kill experiments with penicillin concentrations of 16 times the minimal inhibiting concentrations. Tolerance was identified in 25% (23 of 92) of the isolates from the treatment failure group, in contrast to none of the strains from the treatment success group. Characterization of the strains by M and T typing revealed no predominant type(s) among the tolerant strains. These findings suggest that penicillin tolerance may be responsible for some instances of failure of penicillin to eradicate group A streptococci from the upper respiratory tract of individuals with streptococcal tonsillitis or pharyngitis.