Molecular characteristics of the ompA gene of serotype B Chlamydia trachomatis in Qinghai Tibetan primary school students

To study the molecular characteristics of Chlamydia trachomatis, the major outer membrane protein gene(omp A) of C. trachomatis from primary school students with trachoma residing in the Qinghai Tibetan area was sequenced and compared with the same serotype in Gen Bank. In Jianshetang Primary School and Galeng Central Primary School in the Galeng Tibetan Township of Qinghai Haidong Sala Autonomous County, scraped samples were collected from the upper tarsal conjunctiva and lower conjunctival sac of both eyes of 45 students with trachoma, stored at 4°C, and transported to Beijing Tongren Hospital by air within 24 h. The samples were screened for C. trachomatis by real-time PCR. The omp A gene from the C. trachomatis-positive samples was amplified by nested PCR. The serotype was confirmed by National Center for Biotechnology Information(NCBI) BLAST search and homology analysis. The entire omp A gene sequence was compared with the corresponding gene sequences of serotype B strains available in Gen Bank. Of the 45 students aged 6–13 years with trachoma, 26 C. trachomatis-positive students were identified by the initial real-time PCR screening(average age,(9.09±1.63) years; sex ratio, 1.0), accounting for 57.78%(26/45). The cycle threshold values for real-time PCR were 16.79–37.77. Half(13/26) of C. trachomatis-positive students had a bacterial copy number of 105. The compliance rate of the omp A gene sequences with the C. trachomatis serotype B strains in Gen Bank was up to 99%. Two novel genetic mutations were found when the omp A gene was compared with those of the 11 serotype B strains in Gen Bank. The two non-synonymous mutations were located at(i) position 271 in the second constant domain, an adenine(A) to guanine(G) substitution(ACT?GCT), changing the amino acid at position 91 from threonine to alanine(Thr?Ala) in all 26 strains; and(ii) position 887 in the fourth variable domain, a cytosine(C) to thymine(T) substitution(GCA?GTA), changing the amino acid at residue 296 from alanine to valine(Ala?Val) in four of the 26 strains. Six mutations were identified relative to ATCC VR-573. The strains could be divided into two gene clusters according to the mutation at nucleotide position 887: CQZ-1(China Qinghai Tibetan-1) and CQZ-2(China Qinghai Tibetan-2). We thus detected two novel serotype B mutant strains of C. trachomatis among study subjects with trachoma.     

Differential frequency of NKG2C/<Emphasis Type="Italic">KLRC2</Emphasis> deletion in distinct African populations and susceptibility to Trachoma: a new method for imputation of <Emphasis Type="Italic">KLRC2</Emphasis> genotypes from SNP genotyping data

NKG2C is an activating receptor that is preferentially expressed on natural killer (NK) cells. The gene encoding NKG2C (killer cell lectin-like receptor C2, KLRC2) is present at different copy numbers in the genomes of different individuals. Deletion at the NKG2C locus was investigated in a case–control study of 1522 individuals indigenous to East- and West-Africa and the association with the ocular Chlamydia trachomatis infection and its sequelae was explored. The frequency of homozygous KLRC2 deletion was 13.7 % in Gambians and 4.7 % in Tanzanians. A significantly higher frequency of the deletion allele was found in West-Africans from the Gambia and Guinea-Bissau (36.2 % p = 2.105 × 10^?8, 26.8 % p = 0.050; respectively) in comparison to East-African Tanzanians where the frequency of the deletion is comparable to other human populations (20.9 %). We found no evidence for an association between the numbers of KLRC2 gene copies and the clinical manifestations of trachoma (follicular trachoma or conjunctival scarring). A new method for imputation of KLRC2 genotypes from single nucleotide polymorphism (SNP) data in 2621 individuals from the Gambia further confirmed these results. Our data suggest that NKG2C does not play a major role in trachomatous disease. We found that the deletion allele is present at different frequencies in different populations but the reason behind these differences is currently not understood. The new method offers the potential to use SNP arrays from genome wide association studies to study the frequency of KLRC2 deletion in other populations and its association with other diseases.     

Multilocus sequence typing of genital Chlamydia trachomatis in Norway reveals multiple new sequence types and a large genetic diversity

Background

The Chlamydia trachomatis incidence rate in Finnmark, the most northern and sparsely populated county in Norway, has been twice the national average. This population based cross-sectional study among Finnmark high school students had the following aims: i) to examine distribution of multilocus sequence types (STs) of C. trachomatis in a previously unmapped area, ii) to compare chlamydia genetic diversity in Finnmark with that of two urban regions, and iii) to compare discriminatory capacity of multilocus sequence typing (MLST) with conventional ompA sequencing in a large number of chlamydia specimens.

Methodology

ompA sequencing and a high-resolution MLST system based on PCR amplification and DNA sequencing of five highly variable genetic regions were used. Eighty chlamydia specimens from adolescents aged 15–20 years in Finnmark were collected in five high schools (n = 60) and from routine clinical samples in the laboratory (n = 20). These were compared to routine clinical samples from adolescents in Tromsø (n = 80) and Trondheim (n = 88), capitals of North and Central Norway, respectively.

Principal Findings

ompA sequencing detected 11 genotypes in 248 specimens from all three areas. MLST displayed 50 STs providing a five-fold higher resolution. Two-thirds of all STs were novel. The common ompA E/Bour genotype comprised 46% and resolved into 24 different STs. MLST identified the Swedish new variant of C. trachomatis not discriminated by ompA sequencing. Simpson''s discriminatory index (D) was 0.93 for MLST, while a corrected D_c was 0.97. There were no statistically significant differences in ST genetic diversity between geographic areas. Finnmark had an atypical genovar distribution with G being predominant. This was mainly due to expansion of specific STs of which the novel ST161 was unique for Finnmark.

Conclusions/Significance

MLST revealed multiple new STs and a larger genetic diversity in comparison to ompA sequencing and proved to be a useful tool in molecular epidemiology of chlamydia infections.     

Detection of <Emphasis Type="Italic">Streptococcus pyogenes</Emphasis> virulence genes in <Emphasis Type="Italic">Streptococcus dysgalactiae</Emphasis> subsp. <Emphasis Type="Italic">equisimilis</Emphasis> from Vellore,India

Streptococcus dysgalactiae subsp. equisimilis (SDSE), belonging to the group C and G streptococci, are human pathogens reported to cause clinical manifestations similar to infections caused by Streptococcus pyogenes. To scrutinize the distribution of gene coding for S. pyogenes virulence factors in SDSE, 255 isolates were collected from humans infected with SDSE in Vellore, a region in southern India, with high incidence of SDSE infections. Initial evaluation indicated SDSE isolates comprising of 82.35% group G and 17.64% group C. A multiplex PCR system was used to detect 21 gene encoding virulence-associated factors of S. pyogenes, like superantigens, DNases, proteinases, and other immune modulatory toxins. As validated by DNA sequencing of the PCR products, sequences homologous to speC, speG, speH, speI, speL, ssa and smeZ of the family of superantigen coding genes and for DNases like sdaD and sdc were detected in the SDSE collection. Furthermore, there was high abundance (48.12% in group G and 86.6% in group C SDSE) of scpA, the gene coding for C5a peptidase in these isolates. Higher abundance of S. pyogenes virulence factor genes was observed in SDSE of Lancefield group C as compared to group G, even though the incidence rates in former were lower. This study not only substantiates detection of S. pyogenes virulence factor genes in whole genome sequenced SDSE but also makes significant contribution towards the understanding of SDSE and its increasing virulence potential.     

Multiple Chlamydiaceae species in trachoma: implications for disease pathogenesis and control

Background

Chlamydia trachomatis is a unique obligate intracellular bacterium that remains the leading cause of sexually transmitted bacterial diseases and preventable blindness worldwide. Chronic ocular infections are referred to as trachoma, and predominate in developing countries. Since 2001, the World Health Organization has promoted control strategies including antibiotics, improved hygiene, and environmental measures with limited success. Consequently, a vaccine is urgently needed. Integral to vaccine design is an understanding of the interactions of the pathogen and host immune response. Various animal models of trachoma show that urogenital C. trachomatis strains and other species of the family Chlamydiaceae produce severe conjunctival inflammation and scarring similar to that of the ocular C. trachomatis strains. However, we do not know the extent of organisms that may be involved in human trachoma. Furthermore, C. trachomatis heat shock protein 60 (Hsp60) has been implicated in inflammation and conjunctival scarring but the role of other Chlamydiaceae Hsp60 in disease pathogenesis has not been examined. In this study, we set out to identify whether other Chlamydiaceae species are present in trachoma, and determine their association with severity of clinical disease and with mucosal and systemic immune responses to Chlamydiaceae species-specific Hsp60 to further investigate the immunopathogenesis of this blinding disease.

Methods and Findings

We randomly selected nine of 49 households in a trachoma-endemic region of Nepal. Trachoma was graded, and real-time, quantitative (k)PCR was used to detect genomic DNA and cDNA (from RNA) for Chlamydiaceae ompA and 16S rRNA genes, respectively, from conjunctival swabs. IgG antibody responses to recombinant (r) Chlamydiaceae species-specific Hsp60 were determined for tears and sera. Surprisingly, all three species—C. trachomatis, Chlamydophila psittaci, and Chlamydophila pneumoniae—were detected in eight (89%) study households; one household had no members infected with C. pneumoniae. Of 80 (63%; n = 127) infected individuals, 28 (35%) had infection with C. psittaci, or C. pneumoniae, or both; single and dual infections with C. psittaci and C. pneumoniae were significantly associated with severe conjunctival inflammation (OR 4.25 [95% confidence interval (CI), 2.9–11.3], p = 0.009] as were single infections with C. trachomatis (OR 5.7 [95% CI, 3.8–10.1], p = 0.002). Of the 80 infected individuals, 75 (93.8%) were also positive for 16S rRNA by kPCR for the same organism identified by ompA. Individuals with tear IgG immunoreactivity to Chlamydiaceae rHsp60 were eight times more likely than individuals without tear immunoreactivity to be infected (95% CI 6.4–15.1; p = 0.003), 6.2 times more likely to have severe inflammation (95% CI 4.4–12.6; p = 0.001), and 5.7 times more likely to have scarring (95% CI 3.9–11.1; p = 0.019) while individuals with serum IgG immunoreactivity were 4.1 times more likely to be infected (95% CI 3.1–10.1; p = 0.014).

Conclusions

We provide substantial evidence for the involvement of C. psittaci and C. pneumoniae, in addition to C. trachomatis, in trachoma. The distribution of Chlamydiaceae species by household and age suggests that these infections are widespread and not just sporadic occurrences. Infection with multiple species may explain the failure to detect chlamydiae among active trachoma cases, when only C. trachomatis is assayed for, and the failure of clinically active cases to resolve their disease following what would be considered effective C. trachomatis treatment. The evidence for viable (RNA-positive) organisms of all three species in single and coinfections, the significant association of these infections with severe inflammation, and the significant association of tear and serum IgG responses to Chlamydiaceae Hsp60 with inflammation and scarring, support the role of all three species in disease pathogenesis. Thus, while our findings should be confirmed in other trachoma-endemic countries, our data suggest that a reevaluation of treatment regimens and vaccine design may be required. Understanding the full impact of Chlamydiaceae species on the epidemiology, immunopathology, and disease outcome of trachoma presents a new challenge for Chlamydiaceae research.     

<Emphasis Type="Italic">Raoultella</Emphasis> spp.—clinical significance,infections and susceptibility to antibiotics

The genus Raoultella belongs to the family of Enterobacteriaceae. Raoultella spp. are Gram-negative, aerobic, non-motile rods. This genus can be distinguished from the genus Klebsiella, in that genus use histamine as the only source of carbon in the medium. Also, Raoultella grow at 4 °C and do not produce gas from lactose at 44.5 °C. Raoultella sp. is known to inhabit natural environments (water, soil, plants). The reservoir of Raoultella is the gastrointestinal tract and upper respiratory tract. Raoultella spp. are opportunistic bacteria, which usually cause infections of the biliary tract, pneumonia and bacteraemia in oncologic and with lower immunity patients. Raoultella planticola and Raoultella ornithinolytica are the most frequently encountered human pathogens among the genus Raoultella. In this review, the current knowledge on Raoultella infections is summarized.     

A Questionnaire Survey of the Type of Support Required by <Emphasis Type="Italic">Yogo</Emphasis> Teachers to Effectively Manage Students Suspected of Having an Eating Disorder

Background

Many studies have focused on the decreasing age of onset of eating disorders (EDs). Because school-age children with EDs are likely to suffer worse physical effects than adults, early detection and appropriate support are important. The cooperation of Yogo teachers is essential in helping these students to find appropriate care. To assist Yogo teachers, it is helpful to clarify the encounter rates (the proportion of Yogo teachers who have encountered ED students) and kinds of requested support (which Yogo teachers felt necessary to support ED students). There are no studies that have surveyed the prevalence rates of ED children by ED type as defined by the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5), nor were we able to find any quantitative study surveying the kinds of support Yogo teachers feel helpful to support ED students.

Methods

A questionnaire survey was administered to 655 Yogo teachers working at elementary/junior high/senior high/special needs schools in Chiba Prefecture. The questionnaire asked if the respondents had encountered students with each of the ED types described in DSM-5 (anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), avoidant/restrictive food intake disorder (ARFID), and other types of EDs (Others)), and the kinds of support they felt necessary to support these students. The encounter rates and the kinds of requested were obtained and compared, taking their confidence intervals into consideration.

Results

The encounter rates for AN, BN, BED, ARFID, and Others were 48.4, 14.0, 8.4, 10.7, and 4.6 %, respectively. When classified by school type, AN, BN, BED, and ARFID had their highest encounter rates in senior high schools. Special needs schools had the highest rate for Others. The support most required for all ED types was “a list of medical/consultation institutions.”

Conclusions

Our results have clarified how to support Yogo teachers in the early detection and support of ED students. We found that the encounter rate of AN was the highest, and that it is effective to offer “a list of medical/consultation institutions” to junior and senior high schools where the encounter rates for AN are high.

     

Up-Regulation of Antimicrobial Peptides Gallerimycin and Galiomicin in <Emphasis Type="Italic">Galleria mellonella</Emphasis> Infected with <Emphasis Type="Italic">Candida</Emphasis> Yeasts Displaying Different Virulence Traits

Galleria mellonella has been described as a cheap and an easy-to-reproduce model for the study of fungal infections. We hypothesized that yeasts with higher virulence potential decrease survival and significantly trigger an immune response in G. mellonella through the regulation of innate immunity-related genes encoding antimicrobial peptides (AMPs) such as gallerimycin and galiomicin. Candida albicans SC5314 and Candida dubliniensis CBS 7987, selected because of their different virulence potential, were used for a killing assay followed by the determination of gene expression using qPCR. In vivo results confirmed a significantly (p?=?0.0321) lower pathogenicity for C. dubliniensis than for C. albicans. Accordingly, the induction of C. dubliniensis AMPs was lower at all the selected time points post-infection (1 h, 24 h, 48 h). Moreover, we observed an extremely high regulation of the galiomicin gene compared to the gallerimycin one, suggesting a different role of the tested AMPs in protecting G. mellonella from candidiasis.     

Clinical relevance of infections with zoonotic and human oral species of <Emphasis Type="Italic">Campylobacter</Emphasis>

Genus Campylobacter has been recognized as a causative bacterial agent of animal and human diseases. Human Campylobacter infections have caused more concern. Campylobacters can be classified into two groups in terms of their original host: zoonotic and human oral species. The major zoonotic species are Campylobacter jejuni and Campylobacter coli, which mostly reside in the intestines of avian species and are transmitted to humans via consumption of contaminated poultry products, thus causing human gastroenteritis and other diseases as sequelae. The other campylobacters, human oral species, include C. concisus, C. showae, C. gracilis, C. ureolyticus, C. curvus, and C. rectus. These species are isolated from the oral cavity, natural colonization site, but have potential clinical relevance in the periodontal region to varying extent. Two species, C. jejuni and C. coli, are believed to be mainly associated with intestinal diseases, but recent studies suggested that oral Campylobacter species also play a significant role in intestinal diseases. This review offers an outline of the two Campylobacter groups (zoonotic and human oral), their virulence traits, and the associated illnesses including gastroenteritis.     

Characterisation of manganese peroxidase and laccase producing bacteria capable for degradation of sucrose glutamic acid-Maillard reaction products at different nutritional and environmental conditions

Maillard reactions products (MRPs) are a major colorant of distillery effluent. It is major source of environmental pollution due to its complex structure and recalcitrant nature. This study has revealed that sucrose glutamic acid-Maillard reaction products (SGA-MRPs) showed many absorption peaks between 200 and 450 nm. The absorption maximum peak was noted at 250 nm in spectrophotometric detection. This indicated the formation of variable molecular weight Maillard products during the SGA-MRPs formation at high temperature. The identified aerobic bacterial consortium consisting Klebsiella pneumoniae (KU726953), Salmonella enterica (KU726954), Enterobacter aerogenes (KU726955), Enterobacter cloaceae (KU726957) showed optimum production of MnP and laccase at 120 and 144 h of growth, respectively. The potential bacterial consortium showed decolourisation of Maillard product up to 70% in presence of glucose (1%), peptone (0.1%) at optimum pH (8.1), temperature (37 °C) and shaking speed (180 rpm) within 192 h of incubation. The reduction of colour of Maillard product correlated with shifting of absorption peaks in UV–Vis spectrophotometry analysis. Further, the changing of functional group in FT-IR data showed appearance of new peaks and GC–MS analysis of degraded sample revealed the depolymerisation of complex MRPs. The toxicity evaluation using seed of Phaseolus mungo L. showed reduction of toxicity of MRPs after bacterial treatment. Hence, this study concluded that developed bacterial consortium have capability for decolourisation of MRPs due to high content of MnP and laccase.     

Strain-specific response to ampicillin in <Emphasis Type="Italic">Wolbachia-</Emphasis>infected mosquito cell lines

Wolbachia pipientis (Rickettsiales; Anaplasmataceae) is an obligate intracellular alpha proteobacterium that occurs in arthropods and filarial worms. Some strains of Wolbachia can be maintained as persistent infections in insect cell lines. C/wStr1 cells from the mosquito Aedes albopictus maintain a robust infection with Wolbachia strain wStr, originally isolated from the planthopper, Laodelphax striatellus. To explore possible functions of penicillin-binding proteins expressed from the wStr genome, C/wStr1 cells were exposed to ampicillin. Absolute levels of Wolbachia increased 3.5-fold in ampicillin-treated cells and fivefold in naive cells newly infected with wStr. Because cell numbers were depressed by ampicillin treatment, Wolbachia yield on a per-cell basis increased by 15-fold. The absence of a similar effect on wAlbB in Aa23 host cells suggests that the Wolbachia strain, the presence/absence of genes encoding penicillin-binding proteins, or the interaction between wAlbB and its host cells may modulate the effects of ampicillin.     

Usefulness of the Non-conventional <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis> Model to Assess <Emphasis Type="Italic">Candida</Emphasis> Virulence

Invasive candidiasis is caused mainly by Candida albicans, but other Candida species have increasing etiologies. These species show different virulence and susceptibility levels to antifungal drugs. The aims of this study were to evaluate the usefulness of the non-conventional model Caenorhabditis elegans to assess the in vivo virulence of seven different Candida species and to compare the virulence in vivo with the in vitro production of proteinases and phospholipases, hemolytic activity and biofilm development capacity. One culture collection strain of each of seven Candida species (C. albicans, Candida dubliniensis, Candida glabrata, Candida krusei, Candida metapsilosis, Candida orthopsilosis and Candida parapsilosis) was studied. A double mutant C. elegans AU37 strain (glp-4;sek-1) was infected with Candida by ingestion, and the analysis of nematode survival was performed in liquid medium every 24 h until 120 h. Candida establishes a persistent lethal infection in the C. elegans intestinal tract. C. albicans and C. krusei were the most pathogenic species, whereas C. dubliniensis infection showed the lowest mortality. C. albicans was the only species with phospholipase activity, was the greatest producer of aspartyl proteinase and had a higher hemolytic activity. C. albicans and C. krusei caused higher mortality than the rest of the Candida species studied in the C. elegans model of candidiasis.     

Detection of <Emphasis Type="Italic">Coxiella burnetii</Emphasis> DNA and anti-<Emphasis Type="Italic">Coxiella burnetii</Emphasis> IgG antibodies in precolostral blood samples of stillborn calves in an endemically infected Holstein dairy herd

Coxiella burnetii (C. burnetii), an intracellular zoonotic bacterium causing Q fever, occurs widely in cattle herds. After invasion of the pregnant uterus and initial localization in the placenta, active C. burnetii infections may spread to the fetus hematogenously or by the amniotic-oral route and thus may cause abortion, premature delivery, stillbirth, and weak offspring (APSW) complex. In a case-control study, we investigated precolostral blood samples of 56 stillborn calves and 30 live births from a dairy herd endemically infected with C. burnetii “C-cluster” strains and an increased stillbirth rate in primiparous cows. Within the group of the stillborn calves, four precolostral blood samples (7.1%) were tested positive for C. burnetii DNA by PCR and one serum sample (1.8%) positive for anti-C. burnetii IgG antibodies by a commercial ELISA test, respectively. Neither C. burnetii DNA nor anti-C. burnetii IgG antibodies were detected in the samples of calves being born alive. In conclusion, we demonstrated that coxiellaemia and precolostral seroconversion occurred sporadically in stillborn calves from this endemically infected herd. Due to the low detection rates, C. burnetii could not be confirmed to be the cause of the increased stillbirth rate.     

Culture- and PCR-based detection of BV associated microbiological profile of the removed IUDs and correlation with the time period of IUD in place and the presence of the symptoms of genital tract infection

Objectives

The long-term use of intrauterine devices (IUDs) may lead to biofilm formation on the surface. The aim of this study was to perform the culture- and PCR-based detection of bacteria/fungi from the biofilm of the removed IUDs with different time periods in place.

Methods

For a 2-year period, 100 IUD users were involved in the study. In the majority of the cases, IUDs were removed because of the patients’ complaints. Beside the aerobic and anaerobic culture, species-specific PCR was carried out to detect Chlamydia trachomatis Neisseria gonorrhoeae and the “signalling” bacteria of bacterial vaginosis (BV) in the biofilm removed by vortexing.

Results

Sixty-eight percent of IUDs were used for more than 5 years, 32% were removed after 10 years in place. In 28% of the IUDs?≥?3 different anaerobic species typically found in BV with or without other aerobic bacteria were found by culture method. Streptococcus agalactiae (14%) and Actinomyces spp. (18%) were also isolated frequently. The PCR detection of Gardnerella vaginalis, Atopobium vaginae, Mobiluncus spp. and Ureaplasma urealyticum were 62%, 32%, 23% and 16%, respectively. Seventy-six percent of the IUDs were PCR positive at least for one “signalling” bacterium of BV. C. trachomatis was detected by PCR only in one IUD together with other aerobic and anaerobic bacteria, while the presence of N. gonorrhoeae could not be confirmed from the biofilm of these removed devices.

Conclusion

Sexually transmitted infections (STI)-related bacteria—except for one patient—were not detected on the IUDs removed due to different reasons including clinical symptoms of infection. Presence of any BV “signaling” anaerobic bacteria were detected in a much higher number in the biofilm of the removed IUDs by PCR-based method compared to use culture method (76 versus 28 samples). Different aerobic and anaerobic bacteria colonized an equal number of IUDs, independent of the time-period in place, which may be relevant, if the IUD is removed due to planned pregnancy or due to a fear from upper genital tract infection caused by anaerobic bacteria including Actinomyces spp.

     

Detection of Cryptic <Emphasis Type="Italic">Candida</Emphasis> Species Recognized as Human Pathogens Through Molecular Biology Techniques

Purpose of Review

The aim of this review is to evaluate these molecular-based methods able to identify pathogenic cryptic Candida spp. focusing on those that demonstrated to be useful in clinical laboratory settings.

Recent Findings

It is long known that some Candida spp. are genetically heterogeneous. Firstly, individual species were divided into groups based on differences on the sequence of some genes. Later, those groups were designated as cryptic species and defined as phenotypically indistinguishable species that are only identified by their DNA sequences. Many common Candida spp. are now considered complexes formed by several cryptic species. Some of them have been recognized as human pathogens. The identification of these species is problematic but necessary since they have different host range, infection sites, infection severity, and antifungal susceptibility. Several independent DNA markers were proposed as tools for the differentiation of highly related species. We will concentrate on the three species complexes most frequently associated with human infections including Candida albicans, C. glabrata, and C. parapsilosis complexes and a fourth group of less common but multiresistant species including C. haeumulonii complex and C. auris.

Summary

We review the clinically useful molecular tools able to differentiate the cryptic species of C. albicans, C. glabrata, and C. parapsilosis complexes and designated to uncover emerging multiresistant species.

     

Prevalence of trypanosomes,salivary gland hypertrophy virus and <Emphasis Type="Italic">Wolbachia</Emphasis> in wild populations of tsetse flies from West Africa

Background

Tsetse flies are vectors of African trypanosomes, protozoan parasites that cause sleeping sickness (or human African trypanosomosis) in humans and nagana (or animal African trypanosomosis) in livestock. In addition to trypanosomes, four symbiotic bacteria Wigglesworthia glossinidia, Sodalis glossinidius, Wolbachia, Spiroplasma and one pathogen, the salivary gland hypertrophy virus (SGHV), have been reported in different tsetse species. We evaluated the prevalence and coinfection dynamics between Wolbachia, trypanosomes, and SGHV in four tsetse species (Glossina palpalis gambiensis, G. tachinoides, G. morsitans submorsitans, and G. medicorum) that were collected between 2008 and 2015 from 46 geographical locations in West Africa, i.e. Burkina Faso, Mali, Ghana, Guinea, and Senegal.

Results

The results indicated an overall low prevalence of SGHV and Wolbachia and a high prevalence of trypanosomes in the sampled wild tsetse populations. The prevalence of all three infections varied among tsetse species and sample origin. The highest trypanosome prevalence was found in Glossina tachinoides (61.1%) from Ghana and in Glossina palpalis gambiensis (43.7%) from Senegal. The trypanosome prevalence in the four species from Burkina Faso was lower, i.e. 39.6% in Glossina medicorum, 18.08%; in Glossina morsitans submorsitans, 16.8%; in Glossina tachinoides and 10.5% in Glossina palpalis gambiensis. The trypanosome prevalence in Glossina palpalis gambiensis was lowest in Mali (6.9%) and Guinea (2.2%). The prevalence of SGHV and Wolbachia was very low irrespective of location or tsetse species with an average of 1.7% for SGHV and 1.0% for Wolbachia. In some cases, mixed infections with different trypanosome species were detected. The highest prevalence of coinfection was Trypanosoma vivax and other Trypanosoma species (9.5%) followed by coinfection of T. congolense with other trypanosomes (7.5%). The prevalence of coinfection of T. vivax and T. congolense was (1.0%) and no mixed infection of trypanosomes, SGHV and Wolbachia was detected.

Conclusion

The results indicated a high rate of trypanosome infection in tsetse wild populations in West African countries but lower infection rate of both Wolbachia and SGHV. Double or triple mixed trypanosome infections were found. In addition, mixed trypanosome and SGHV infections existed however no mixed infections of trypanosome and/or SGHV with Wolbachia were found.

     

QTL analysis and the development of closely linked markers for days to flowering in spring oilseed rape (<Emphasis Type="Italic">Brassica napus</Emphasis> L.)

Days to flowering (DTF) is an important trait impacting cultivar performance in oilseed rape (Brassica napus L.), but the interaction of all loci controlling this trait in spring-type oilseed rape is not fully understood. We identified quantitative trait loci (QTL) for variation in DTF in a doubled haploid (DH) population from the Qinghai–Tibet Plateau that includes 217 lines derived from a cross between spring-type oilseed rape (B. napus L.) line No. 5246 and line No. 4512, the latter of which is responsive to the effective accumulated temperature (EAT). A linkage map was constructed for the DH population, using 202 SSR and 293 AFLP markers. At least 22 DTF QTL were found in multiple environments. Four major QTL were located on linkage groups A7, C2, C8 and C8. Among these QTL, cqDTFA7a and cqDTFC2a were identified in five environments and individually explained 10.4 and 23.0 % of the trait variation, respectively. cqDTFC8, a major QTL observed in spring environments, and a unique winter environment QTL, qDTFC8-3, were identified; these QTL explained 10.0 and 46.5 % of the phenotypic variation, respectively. Minor QTL (for example, cqDTFC2c) and epistatic interactions seemed evident in this population. Two closely linked SSR markers for cqDTFA7a and cqDTFC8 were developed (G1803 and S034). BnAP1, a B. napus gene with homology to Arabidopsis thaliana that was identified as a cqDTFA7a candidate gene, played a major role in this study. The allelic effects of the major and minor QTL on DTF were further validated in the DH population and in 93 breeding genotypes.