TESTING A SUBTYPE-SPECIFIC GP41 AMPLIFICATION METHOD FOR GENOTYPING INDIVIDUALS INFECTED BY HUMAN IMMUNODEFICIENCY VIRUS TYPE-1 IN THE BRAZILIAN POPULATION OF ITAJAÍ, SOUTH BRAZIL

The method used by YAGYU et al. for the subtype-specific polymerase chain reaction (PCR) amplification of the gp41 transmembrane region of the human immunodeficiency virus type-1 (HIV-1) env gene, was tested. HIV-1 proviral DNA from 100 infected individuals in Itajaí, South Brazil was used to analyze this method. Seventy individuals were determined according to this method as having PCR products at the expected size for subtypes B, C, D and F. Of these individuals, 26 (37.1%) were observed as having the expected amplification for subtype C, and 42 (60%) were observed as having the expected products for subtypes B and D. Of the subtype B and D amplicons, 16 (22.9%) were classified as subtype D, and 26 (37.1%) were classified as subtype B. Two individuals (2.9%) had amplicons that were observed after subtype F-specific amplification was performed. Sequencing and comparing the patient sequences to reference sequences confirmed the classification of sequences of subtypes C and B. However, sequences that were falsely determined as being D and F in the PCR assay were determined as being subtypes C and B, respectively, by sequence analysis. For those individuals from whom no amplified products were obtained, a low viral load that was indicated in their patient history may explain the difficulty in subtyping by PCR methods. This issue was demonstrated by the results of ANOVA when testing the effect of viral load on the success of PCR amplification. The alignment of the obtained sequences with HIV-1 reference sequences demonstrated that there is high intra-subtype diversity. This indicates that the subtype-specific primer binding sites were not conserved or representative of the subtypes that are observed in the Brazilian populations, and that they did not allow the correct classification of HIV-1 subtypes. Therefore, the proposed method by YAGYU et al. is not applicable for the classification of Brazilian HIV-1 subtypes.

PREVALENCE OF HERPES SIMPLEX VIRUS TYPE 2 AND RISK FACTORS ASSOCIATED WITH THIS INFECTION IN WOMEN IN SOUTHERN BRAZIL

SUMMARY The herpes simplex virus type 2 (HVS-2) is the most prevalent infection worldwide. It is a cofactor in the acquisition of human immunodeficiency virus (HIV) and the persistence of human papillomavirus (HPV). This study evaluated the prevalence of HSV-2, using the polymerase chain reaction (PCR), and associated factors in patients treated at the Federal University of Rio Grande (FURG) and Basic Health Units (BHU) in Rio Grande, Brazil. The observed prevalence of HSV-2 was 15.6%. Among the 302 women studied, 158 had received assistance in BHU and 144 were treated at FURG. The prevalence of HSV-2 in these groups was 10.8% and 20.8%, respectively, RR 1.9 and p = 0.012. Knowledge about the Pap smear, and the presence of lesions showed no association with HSV-2 infection. Multivariate analysis showed that the variable that most influenced the risk of HSV-2 infection was the presence of HIV infection, with a relative risk of 1.9 and p = 0.04. Discussion: Genital ulcers are an important entry point for HIV, and condom use is an important strategy to reduce transmission of HIV and HSV-2.

ORIGIN AND PREVALENCE OF HUMAN T-LYMPHOTROPIC VIRUS TYPE 1 (HTLV-1) AND TYPE 2 (HTLV-2) AMONG INDIGENOUS POPULATIONS IN THE AMERICAS

Human T-lymphotropic virus type 1 (HTLV-1) is found in indigenous peoples of the Pacific Islands and the Americas, whereas type 2 (HTLV-2) is widely distributed among the indigenous peoples of the Americas, where it appears to be more prevalent than HTLV-1, and in some tribes of Central Africa. HTLV-2 is considered ancestral in the Americas and is transmitted to the general population and injection drug users from the indigenous population. In the Americas, HTLV-1 has more than one origin, being brought by immigrants in the Paleolithic period through the Bering Strait, through slave trade during the colonial period, and through Japanese immigration from the early 20th century, whereas HTLV-2 was only brought by immigrants through the Bering Strait. The endemicity of HTLV-2 among the indigenous people of Brazil makes the Brazilian Amazon the largest endemic area in the world for its occurrence. A review of HTLV-1 in all Brazilian tribes supports the African origin of HTLV-1 in Brazil. The risk of hyperendemicity in these epidemiologically closed populations and transmission to other populations reinforces the importance of public health interventions for HTLV control, including the recognition of the infection among reportable diseases and events.

Clonal structure of Trypanosoma cruzi Colombian strain (biodeme Type III): biological, isoenzymic and histopathological analysis of seven isolated clones

The clonal structure of the Colombian strain of Trypanosoma cruzi, biodeme Type III and zymodeme 1, was analyzed in order to characterize its populations and to establish its homogeneity or heterogeneity. Seven isolated clones presented the basic characteristics of Biodeme Type III, with the same patterns of parasitemic curves, tissue tropism to skeletal muscle and myocardium, high pathogenicity with extensive necrotic-inflammatory lesions from the 20th to 30th day of infection. The parental strain and its clones C1, C3, C4 and C6, determined the higher levels of parasitemia, 20 to 30 days of infection, with high mortality rate up to 30 days (79 to 100%); clones C2, C5 and C7 presented lower levels of parasitemia, with low mortality rates (7.6 to 23%). Isoenzymic patterns, characteristic of zymodeme 1, (Z1) were similar for the parental strain and its seven clones. Results point to a phenotypic homogeneity of the clones isolated from the Colombian strain and suggest the predominance of a principal clone, responsible for the biological behavior of the parental strain and clones.

Response to chemotherapy with benznidazole of clones isolated from the 21SF strain of Trypanosoma cruzi (biodeme Type II, Trypanosoma cruzi II)

Susceptibility to chemotherapy with benznidazole was investigated of 5 clones isolated from the 21 SF strain (biodeme Type II, Trypanosoma cruzi II). Swiss mice were infected with the parental strain for each clone and submitted to chemotherapy with benznidazole (100mg/kg/day during 90 days). Treatment determined negativity of the parasitemia. Cure rates were evaluated by parasitological cure tests. Serology was evaluated for treated animals (titers from negative to 1:640) and untreated controls (1:160 to 1:640). Cure rates varied from 30 to 100% for the 5 clones, and were 25% for the parental strain. Results suggested that the variability of response to treatment of the clonal populations of Trypanosoma cruzi II strains is responsible for the high variation in the response to chemotherapy with benznidazole and nifurtimox by strains of this biodeme.

High prevalence of methicillin-resistant Staphylococcus aureus with SCCmec type III in cystic fibrosis patients in southern, Brazil

INTRODUCTION: Bacterial colonization of the lungs is the main cause of morbidity in cystic fibrosis (CF). Pathogens such as Staphylococcus aureus are very well adapted to the pulmonary environment and may persist for years in the same patient. Genetic determinants of these bacteria, such as the presence of SCCmec have recently emerged as a problem in this population of patients. METHODS: Staphylococcus aureus isolates obtained from different clinical materials coming from CF and non-CF patients attended at a cystic fibrosis reference hospital were compared according to SCCmec type and antibiotic susceptibility profile. RESULTS: Three hundred and sixty-four single-patient Staphylococcus aureus isolates were collected, of which 164 (45%) were from CF patients. Among the latter, 57/164 (44.5%) were MRSA, and among the non-CF patients, 89/200 (35%) were MRSA. Associated pathogens were found in 38 CF patients. All 57 MRSA from CF patients harbored the multiresistant cassette type III. In contrast, 31/89 MRSA from non-CF patients harbored SCCmec type I (35%) and 44/89 harbored type III (49%). The antibiotic susceptibility pattern was similar between CF and non-CF patients. CONCLUSIONS: The high prevalence of multiresistant SCCmec type III among CF patients compared with non-CF patients in our institution may make it difficult to control disease progression through antibiotic therapy for promoting the survival of this kind of patient.

Cryptococcus gattii molecular type VGII as agent of meningitis in a healthy child in Rio de Janeiro, Brazil: report of an autochthonous case

Cryptococcus gattii causes meningoencephalitis in immunocompetent hosts, occurring endemically in some tropical and subtropical regions. Recently, this fungus was involved in an outbreak in Vancouver Island and British Columbia (Canada). In this temperate region, the VGII type is predominant. The paper describes an autochthonous case of meningoencephalitis by C. gattii VGII in a previously health child in Rio de Janeiro, considered nonendemic region of Brazil. The fungus was identified by biochemical tests and the molecular type was determined by URA5-RFLP. The present report highlights the need for clinical vigilance for primary cryptococcal meningitis in nonendemic areas.

Community-acquired methicillin-resistant Staphylococcus aureus carrying SCCmec type IV in southern Brazil

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen commonly associated with nosocomial infections. However, it has also been associated with community-acquired skin and soft tissue infections (CA-MRSA). There are few data on the identification and prevalence of CA-MRSA infections in Brazil. METHODS: This is a cross-sectional study of 104 patients with community-acquired skin infections attending two health care centers in Porto Alegre, southern Brazil. MRSA isolates were characterized by molecular methods, including detection of the mecA gene by PCR, gene SCCmec typing, Panton-Valentine leukocidin (PVL) detection, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). RESULTS: From the 104 samples, 58 Staphylococcus aureus isolates were obtained, of which five (8.6%) had a CA-MRSA-resistant profile. All five isolates had the mecA gene and amplified to SCCmec type IV. Analysis of chromosomal DNA by PFGE revealed the presence of two clusters related to international clones (OSPC and USA 300), with a Dice similarity coefficient >80%. The study was complemented by MLST, which detected three different strains: ST30, ST8, and ST45, the latter not presenting any relation with the clones compared in PFGE. CONCLUSIONS: The presence of CA-MRSA reveals an important change in the epidemiology of this pathogen and adds new elements to the knowledge of the molecular biology of infections by MRSA with SCCmec type IV in southern Brazil.

Sexual transmission of human T-cell lymphotropic virus type 1

Human T-cell lymphotropic virus type 1 (HTLV-1) is endemic in many parts of the world and is primarily transmitted through sexual intercourse or from mother to child. Sexual transmission occurs more efficiently from men to women than women to men and might be enhanced by sexually transmitted diseases that cause ulcers and result in mucosal ruptures, such as syphilis, herpes simplex type 2 (HSV-2), and chancroid. Other sexually transmitted diseases might result in the recruitment of inflammatory cells and could increase the risk of HTLV-1 acquisition and transmission. Additionally, factors that are associated with higher transmission risks include the presence of antibodies against the viral oncoprotein Tax (anti-Tax), a higher proviral load in peripheral blood lymphocytes, and increased cervicovaginal or seminal secretions. Seminal fluid has been reported to increase HTLV replication and transmission, whereas male circumcision and neutralizing antibodies might have a protective effect. Recently, free virions were discovered in plasma, which reveals a possible new mode of HTLV replication. It is unclear how this discovery might affect the routes of HTLV transmission, particularly sexual transmission, because HTLV transmission rates are significantly higher from men to women than women to men.

The use of botulinum toxin type A in the treatment of HTLV-1-associated overactive bladder refractory to conventional therapy

Urinary symptoms occur in 19% of human T-cell lymphotropic virus type 1 (HTLV-1)-infected patients who do not fulfill criteria for HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and in almost 100% of HAM/TSP patients. Few studies have evaluated therapies for overactive bladder (OAB) caused by HTLV-1 infection. This case report describes the effect of onabotulinum toxin A on the urinary manifestations of three patients with HAM/TSP and OAB symptoms. The patients were intravesically administered 200 units of Botox®. Their incontinence episodes improved, and their OAB symptoms scores (OABSS) reduced significantly. These data indicate that Botox® should be a treatment option for OAB associated with HTLV-1 infection.

Surgical treatment of type I neuritis in a teenage boy with borderline tuberculoid leprosy

Exacerbation of the immune response against Mycobacterium leprae can lead to neuritis, which is commonly treated via immunosuppression with corticosteroids. Early neurolysis may be performed concurrently, especially in young patients with a risk of functional sequelae. We report the case of a young patient experienced intense pain in the left elbow one year after the treatment of tuberculoid-tuberculoid leprosy. The pain was associated with paresthesias in the ulnar edge and left ulnar claw. After evaluation, the diagnosis was changed to borderline tuberculoid leprosy accompanied with neuritis of the left ulnar nerve. Early neurolysis resulted in rapid reduction of the pain and recovery of motor function.

Oropharyngeal colonization by Haemophilus influenzae in healthy children from Taubaté (São Paulo), prior to the Haemophilus influenzae type b vaccination program in Brazil

Haemophilus influenzae is one of the most important bacterial agents of otitis and sinusitis. H. influenzae type b (Hib) is one of the main causes of meningitis, pneumonia, and septicemia in nonvaccinated children under 6 years of age. The aims of this study were to determine the prevalence of H. influenzae and Hib oropharyngeal colonization prior to the onset of the Hib vaccination program in Brazil in previously healthy children and to assess the susceptibility profile of this microorganism to a selected group of antimicrobials that are used to treat acute respiratory infections. METHOD: Cultures of Haemophilus influenzae were made from oropharynx swabs from 987 children under 6 years of age who were enrolled in 29 day-care centers in Taubaté (a city of São Paulo state, Brazil) between July and December 1998. RESULTS: The prevalence of H. influenzae carriers was 17.4%, and only 5.5% of the strains were beta-lactamase producers. The prevalence of Hib carriers was high, 7.3% on average (range, 0.0 - 33.3%). CONCLUSIONS: The low prevalence of colonization by penicillin-resistant strains indicates that it is not necessary to substitute ampicilin or amoxicilin to effectively treat otitis and sinusitis caused by H. influenzae in Taubaté.