Mixed infection and two different resistance profiles of Treponema pallidum to macrolides identified in some clinical specimens of the same patient / Infecção mista e resistência diferente a macrolídeos em Treponema pallidum identificadas por variadas espécimes clínicos em um mesmo paciente

Syphilis represents a global public health problem. The resistance of Treponema pallidum to macrolides is related to the mutation in the 23S rRNA gene (A2058G). We reported a case of secondary syphilis in a 52-year-old man presenting two profiles: the first one of susceptibility, and the other one of resistance, when we analyzed the 23S rRNA gene sequence from two different clinical specimens of the same infectious episode. DNA from T. pallidum from skin biopsy presented resistance profile, whereas T. pallidum DNA from blood presented a profile of susceptibility to macrolides. These results suggest it was mixed infection or reinfection.

A sífilis representa um problema de saúde pública mundial. A resistência de Treponema pallidum aos macrolídeos está relacionada à mutação no gene 23S rRNA (A2058G). Relatamos um caso de sífilis secundária, em um homem de 52 anos, com um perfil de suscetibilidade e outro de resistência, ao analisarmos a sequência do gene 23S rRNA de dois espécimes clínicos diferentes, do mesmo episódio infeccioso. A amostra de DNA de T. pallidum proveniente de raspado dérmico da lesão apresentou um perfil de resistência, enquanto aquele que derivou de sangue apresentou perfil de suscetibilidade aos macrolídeos. Esses resultados sugerem tratar-se de infecção mista ou de reinfecção.

Cutaneous and visceral leishmaniasis co-infection in dogs from Rio de Janeiro, Brazil: evaluation by specific PCR and RFLP-PCR assays.

INTRODUCTION: During a diagnostic evaluation of canine visceral leishmaniasis (VL), two of seventeen dogs were found to be co-infected by Leishmania (Viannia) braziliensis and Leishmania (Leishmania) chagasi. METHODS: Specific polymerase chain reaction (PCR) and restriction fragment length polymorphism-PCR (RFLP-PCR) assays were performed. RESULTS: PCR assays for Leishmania subgenus identification followed by RFLP-PCR analysis in biopsies from cutaneous lesions and the spleen confirmed the presence of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) chagasi in those fragments. CONCLUSIONS: This report reinforces the importance of using serological and molecular techniques in the epidemiological surveillance of canine populations in endemic areas in which both diseases are known to co-exist. In such cases, a reassessment of the control measures is required.

Canine Cutaneous Leishmaniasis: Dissemination and Tissue Tropism of Genetically Distinct Leishmania (Viannia) braziliensis Populations.

Little is known regarding the internal dissemination of initial cutaneous lesions and tissue tropism of Leishmania (Viannia) braziliensis populations in naturally infected dogs. The aim of this study was to investigate genetic polymorphisms of L. (V.) braziliensis populations in different anatomic sites of naturally infected dogs by using polymerase chain reaction (PCR) and low-stringency single specific primer-PCR (LSSP-PCR) techniques. The amplified products were analyzed by LSSP-PCR to investigate the genetic variability of the parasite populations present in different anatomical sites. Twenty-three out of the 52 samples gave PCR-positive results. The existence of L. (V.) braziliensis strains that remained restricted to cutaneous lesions and others showing characteristics of dissemination to internal organs and healthy skin was observed. LSSP-PCR and numerical analyses revealed that parasite populations that do not disseminate were genetically similar and belonged to a separate phenetic cluster. In contrast, populations that showed spreading to internal organs displayed a more polymorphic genetic profile. Despite the heterogeneity, L. (V.) braziliensis populations with identical genetic profiles were observed in popliteal and cervical lymph nodes of the same animal. Our results indicate that infection in dogs can be manifested by dissemination and tissue tropism of genetically distinct populations of L. (V.) braziliensis.

Sylvatic and peridomestic populations of Triatoma pseudomaculata are not significantly structured by habitat, as revealed by two genetic markers.

Chagas disease remains a public health concern in Brazil and other Latin American countries, mainly due to the potential domiciliation of native triatomine species. We analyzed the genetic variability of Triatoma pseudomaculata in sylvatic and peridomestic ecotopes throughout three localities in the northeastern state of Bahia, Brazil. We studied polymorphisms generated by random amplified polymorphic DNA (RAPD) and isoenzyme electrophoresis analyses. Based on RAPD analysis, each specimen was assigned to one of three genetic clusters. Although all sylvatic specimens from one locality were grouped into the same cluster, sylvatic and peridomestic specimens from the other two localities were broadly distributed between the remaining two clusters, suggesting that geographic population structuring was not occurring. Furthermore, isoenzyme analysis suggested that distinct populations were in Hardy-Weinberg equilibrium. Low statistical values for Wright's Fst index also supported the absence of population structuring and suggested the occurrence of panmixia. We conclude that genetic flow occurs between sylvatic and peridomestic T. pseudomaculata populations, probably as a consequence of passive and active dispersion of the insects, associated with deforestation and anthropic transformations.

Parasite genotypically related to a monoxenous trypanosomatid of dog's flea causing opportunistic infection in an HIV positive patient

An HIV positive patient presenting a clinical picture of visceral leishmaniasis co-infection was submitted to a bone marrow aspiration after admission to hospital. Amastigotes forms were seen in the bone marrow aspirate and the parasite grew in culture as promastigotes. Molecular analyses showed that the flagellates isolated did not belong to the genera Leishmania, Trypanosoma or Sauroleishmania. It was not possible to establish infection in laboratory animals. In vitro culture of mouse peritoneal macrophages revealed the invasion of the host cells by the flagellates and their killing 48 hr after infection. Opportunistic infection with an insect trypanosomatid was suspected. Further hybridization analyses against a pannel of different monoxenous and heteroxenous trypanosomatids showed kDNA cross-homology with Leptomonas pulexsimulants a trypanosomatid found in the dog's flea.

Isoenzymes detect variation in population of Triatoma brasiliensis (Hemiptera: Reduviidae: Triatominae)

Triatoma brasiliens is one of the most important vectors of Chagas diseases in the semiarid zone of the northeast of Brazil. Intraspecific morphological and behavioural variation has been reported for different populations. Results for four distinct populations using eight isoenzymes are reported here. The literature descibes three subspecies: T. brasiliensis Neiva, 1991; T. brasiliensis melanica Neiva & Lent, 1941 and T. brasiliensis macromelasoma Galvao, 1956. These subspecies differ mainly in their cuticle colour pattern and were regarded as synonyms by Lent and Wygodzinsky (1979). In order to evaluate whether the chromatic pattern is a morphological variation of different melanic forms within T. brasiliensis or due to interspecific variation, field collections were performed in localities where these three subspecies have been described: Caico (Rio Grande do Norte), the type-locality for T. b. brasileiensis; Petrolina (Pernambuco) for T. B. macromelasoma and Espinosa (Minas Gerais) for T. b. melanica. A fourth distinct chromatic pattern was found in Juazeiro (Bahia). A total of nine loci were studied. Values of Nei's genetic distance (D) were calculated. T. b. brasiliensis and T. b. macromelasoma are the closest populations with a D=0.295. T. b. melanica had a Dò0.537 when compared to the others, a distance in ther range of interspecific variation for other triatomine species.