Virulence Factors and Antifungal Susceptibility in Candida Species Isolated from Dermatomycosis Patients.

Dermatomycoses caused by Candida spp. are increasingly common, however there are few reports in the literature regarding their epidemiology, pathogenesis and antifungal susceptibility of these fungal pathogens. This study aimed to identify, characterize virulence and determine the antifungal susceptibility of Candida species isolated from patients with dermatomycoses. We studied a total of 45 yeast samples isolated from dermal scrapings from patients treated at a public hospital, Bauru, São Paulo, Brazil. After identification, the samples were analyzed for protease activity, phospholipase, biofilm formation and antifungal susceptibility. The most common species was Candida albicans (40%), followed by C. krusei (22.22%), C. parapsilosis complex (22.22%) and C. famata (6.67%). Regarding virulence mechanisms, 57.78% and 28.89% of the samples showed enzymatic activity for protease and phospholipase, respectively. A total of 13.33% of the samples showed secretion of both enzymes. All isolates were biofilm producers, and a higher production was observed in C. tropicalis isolates. Regarding the antifungal susceptibility test, 97.78% of the samples had the highest levels of the minimal inhibitory concentration (MIC) for terbinafine, and one C. krusei sample showed intermediate susceptibility to fluconazole. The correct identification of dermatomycosis-related microorganisms, as well as a better knowledge of their pathogenicity and susceptibility against the antifungals used in the clinic, is extremely important for an efficient preventive and therapeutic action.

Tuberculosis associated factors caused by Mycobacterium tuberculosis of the RDRio genotype.

BACKGROUND: Tuberculosis (TB) continues to be a disease that affects many countries around the world, including Brazil. Recently, a subtype of Latin American-Mediterranean family strain was identified and characterised by RDRio. The strain has been associated with different characteristics of the disease. OBJECTIVES: In the present study we investigated the association of epidemiological, clinical, radiological and bacteriological variables with pulmonary tuberculosis caused by RDRioMycobacterium tuberculosis strain in large regions of São Paulo. METHODS: We conducted a cross-sectional study in 530 patients with pulmonary tuberculosis, diagnosed using sputum culture, from two regions of the São Paulo state in Brazil. The samples were brought to São Paulo reference laboratories for epidemiological, clinical, radiological and bacteriological analyses, and the data were obtained from a TB notification system. RDRio genotyping and Spoligotyping of the samples were performed. For the analysis of the categorical variables we used the chi-square test or the Fisher's exact test, and for the continuous variables, the Mann-Whitney test. In addition, a logistic regression was used for multivariate analysis. Differences with p < 0.05 were considered significant. FINDINGS THE RDRIO: deletion was identified in 152 (28.7%) samples. In the univariate analysis, both the age groups above 25 years and alcohol consumption were associated with the RDRio deletion. The multivariate analysis confirmed the association of the RDRio deletion with the age groups: 25-35 years old [OR: 2.28 (1.02-5.07; p = 0.04)] and 36-60 years old (OR: 2.36 (1.11-5.05); p = 0.03], and also with alcohol consumption [OR: 1.63 (1.05-2.54); p = 0,03]. MAIN CONCLUSIONS: In this study, we identified new factors associated with the M. tuberculosis of the RDRio deletion strains infection.

Clinical and epidemiological profiles of individuals with drug-resistant tuberculosis.

Drug-resistant tuberculosis (TB) is a growing global threat. Approximately 450,000 people developed multidrug-resistant TB worldwide in 2012 and an estimated 170,000 people died from the disease. This paper describes the sociodemographic, clinical-epidemiological and bacteriological aspects of TB and correlates these features with the distribution of anti-TB drug resistance. Mycobacterium tuberculosis (MT) cultures and drug susceptibility testing were performed according to the BACTEC MGIT 960 method. The results demonstrated that MT strains from individuals who received treatment for TB and people who were infected with human immunodeficiency virus were more resistant to TB drugs compared to other individuals (p < 0.05). Approximately half of the individuals received supervised treatment, but most drug-resistant cases were positive for pulmonary TB and exhibited positive acid-fast bacilli smears, which are complicating factors for TB control programs. Primary healthcare is the ideal level for early disease detection, but tertiary healthcare is the most common entry point for patients into the system. These factors require special attention from healthcare managers and professionals to effectively control and monitor the spread of TB drug-resistant cases.

Molecular and spatial evaluation of small rodents and Didelphimorphis infected with Mycobacterium leprae in the southern Amazon, Brazil.

BACKGROUND: The high levels of recent transmission of leprosy worldwide demonstrate the necessity of epidemiologic surveillance to understand and control its dissemination. Brazil remains the second in number of cases around the world, indicating active transmission of Mycobacterium leprae (M. leprae) in the population. At this moment, there is a consensus that the bacillus is transmitted by inter-human contact, however, different serologic, molecular, and histopathological approaches indicate the existence of non-human transmission sources. METHODS AND RESULTS: The qPCR assay was used to amplify the molecular targets 16S RNAr and RLEP, in samples of liver, spleen, and ear of wild animals belonging to Didelphimorphia and Rodentia orders, in highly endemic areas of Mato Grosso, Brazil. The RLEP repetitive sequence was positive in 202 (89.0%) samples, with 96 (42.3%) of these also being positive for the 16S gene. Regarding the collection sites, it was observed that the animals were found in areas profoundly deforested, close to urban areas. CONCLUSIONS: Our results suggest that wild animals can play an important role in the maintenance of M. leprae in endemic regions with major anthropic action in Brazil. Therefore, integrating human, animal, and environmental health care with the One Health initiative is highly efficient for the development of effective strategies to contain and control leprosy in Brazil.

The Effect of Geoclimatic Factors on the Distribution of Paracoccidioidomycosis in Mato Grosso do Sul, Brazil.

The incidence of paracoccidioidomycosis (PCM) varies in Latin America, and it is influenced by environmental factors. This study evaluated the distribution of PCM acute/subacute form (AF) cases and their correlation with geoclimatic factors in the Mato Grosso do Sul (MS) state. The study included 81 patients diagnosed with the PCM/AF at the University Hospital of the Federal University of Mato Grosso do Sul between January 1980 and February 2022. Geographic coordinates, health microregion of patient's residence, compensated average temperature, relative air humidity (RH), El Niño Southern Oscillation (ENSO), and average global temperature were analyzed. The highest incidence was observed in the Aquidauana (7/100,000 inhabitants), while Campo Grande, the state's capital, had the highest number (n = 34; 42.4%) and density (4.4 cases/km2) of cases. The number of cases increased during extended periods of the El Niño phenomenon. A positive correlation was found between higher RH and PCM/AF cases. Most PCM/AF cases were found in areas with loamy soils and RH ranging from 60.8 to 73.6%. In MS, the health microregions of PCM/AF patients are characterized by deforestation for agricultural and pasture use, coupled with loamy soils and specific climatic phenomena leading to higher soil humidity.

Genetic diversity of Mycobacterium leprae in the state of São Paulo, an area of low-leprosy incidence in Brazil.

BACKGROUND: Brazil has the second largest number of leprosy cases worldwide, and the state of São Paulo has been considered non-endemic since 2006. METHODS: We analyzed 16 variable number tandem repeats loci and three single nucleotide polymorphisms loci of Mycobacterium leprae (M. leprae) in 125 clinical isolates from patients in different municipalities in the state. RESULTS: The clustering pattern of M. leprae indicated that the transmission of leprosy persisted in the state and included scenarios of intra-extra-familial transmission in areas with low endemicity. CONCLUSIONS: A significantly active circulation of M. leprae was observed. Therefore, surveillance and control measures must be implemented.

Genotyping of Mycobacterium leprae present on Ziehl-Neelsen-stained microscopic slides and in skin biopsy samples from leprosy patients in different geographic regions of Brazil.

We analysed 16 variable number tandem repeats (VNTR) and three single-nucleotide polymorphisms (SNP) in Mycobacterium leprae present on 115 Ziehl-Neelsen (Z-N)-stained slides and in 51 skin biopsy samples derived from leprosy patients from Ceará (n = 23), Pernambuco (n = 41), Rio de Janeiro (n = 22) and Rondônia (RO) (n = 78). All skin biopsies yielded SNP-based genotypes, while 48 of the samples (94.1%) yielded complete VNTR genotypes. We evaluated two procedures for extracting M. leprae DNA from Z-N-stained slides: the first including Chelex and the other combining proteinase and sodium dodecyl sulfate. Of the 76 samples processed using the first procedure, 30.2% were positive for 16 or 15 VNTRs, whereas of the 39 samples processed using the second procedure, 28.2% yielded genotypes defined by at least 10 VNTRs. Combined VNTR and SNP analysis revealed large variability in genotypes, but a high prevalence of SNP genotype 4 in the Northeast Region of Brazil. Our observation of two samples from RO with an identical genotype and seven groups with similar genotypes, including four derived from residents of the same state or region, suggest a tendency to form groups according to the origin of the isolates. This study demonstrates the existence of geographically related M. leprae genotypes and that Z-N-stained slides are an alternative source for M. leprae genotyping.

Social school contacts of multibacillary leprosy cases in children living in the hyperendemic region of the Midwest of Brazil.

OBJECTIVE: To analyze the prevalence of Mycobacterium leprae detection and the associated factors among social contacts in the school environment of multibacillary cases living in a hyperendemic municipality of the state of Mato Grosso. METHODS: Cross-sectional study with 236 social contacts of multibacillary leprosy from public schools and residents in Cuiabá (Mato Grosso) in 2018. The sources of information were interviews and nasal swab tests for molecular analysis by polymerase chain reaction - PCR. For the prevalence ratio estimates, crude and adjusted analyses were performed using robust Poisson regression and their respective confidence intervals (95% CI). The ArcGIS 9.1 software was used for the geographic distribution analyses. RESULTS: The prevalence of detection of M. leprae in social contacts was 14%. A total of 63.6% of the schools surveyed had 5.1% to 50% of the social contacts of leprosy with positive PCR. The analysis of the geographic distribution in the neighborhoods showed a high prevalence of infection, being higher than 50% in some localities. The highest proportion of positive results occurred in the northern region of the city and from a precarious socioeconomic class. CONCLUSION: The results showed a high prevalence of detection of M. leprae among social contacts in areas with poor socioeconomic conditions. In these regions, there is a greater risk of infection and of getting sick.

Genetic diversity of mycobacterium leprae isolates from Brazilian leprosy patients.

INTRODUCTION: Leprosy is a chronic disease caused by infection with Mycobacterium leprae, an obligate intracellular parasite. A problem in studying the transmission of leprosy is the small amount of variation in bacterial genomic DNA. The discovery of variable number of tandem repeats (VNTRs) allowed the detection of strain variation in areas with a high prevalence of leprosy. Four genotypes of M. leprae based on three single-nucleotide polymorphism (SNPs) were also discovered to be useful for analysis of the global spread of leprosy. METHODS: In this present study, we examined the allelic diversity of M. leprae at 16 select VNTR and three SNP loci using 89 clinical isolates obtained from patients mainly from the neighbouring states of São Paulo and Rio de Janeiro Brazil. RESULTS AND CONCLUSION: By use of a PCR-RFLP-based procedure that allows the recognition of SNP types 3 and 4 without the need for the more expensive DNA sequencing steps, characterisation of the main M. leprae genotypes was easy. When applied on the study population, it was found that the SNP type 3 is most frequent in these two states of Brazil, and that VNTRs provided further discrimination of the isolates. Two Short Tandem Repeats (STRs) were monomorphic, with the remaining 14 STRs represented by two to 18 alleles. Epidemiological associations with township or state were not evident in this random collection and require further investigations. In phylogenetic trees, branches formed by all 16 STRs clearly separated SNP type 3 organisms from the other types while the allelic patterns of two minisatellite loci 27-5 and 12-5 were highly correlated with SNP type 3. This strain typing study provide the basis for comparison of M. leprae strain types within Brazil and with those from other countries, and informed selection of genomic markers and methods for future studies.

Genetic diversity of Mycobacterium leprae in the state of São Paulo, an area of low-leprosy incidence in Brazil

ABSTRACT Background: Brazil has the second largest number of leprosy cases worldwide, and the state of São Paulo has been considered non-endemic since 2006. Methods: We analyzed 16 variable number tandem repeats loci and three single nucleotide polymorphisms loci of Mycobacterium leprae (M. leprae) in 125 clinical isolates from patients in different municipalities in the state. Results: The clustering pattern of M. leprae indicated that the transmission of leprosy persisted in the state and included scenarios of intra-extra-familial transmission in areas with low endemicity. Conclusions: A significantly active circulation of M. leprae was observed. Therefore, surveillance and control measures must be implemented.

Social school contacts of multibacillary leprosy cases in children living in the hyperendemic region of the Midwest of Brazil

Abstract Objective: To analyze the prevalence of Mycobacterium leprae detection and the associated factors among social contacts in the school environment of multibacillary cases living in a hyperendemic municipality of the state of Mato Grosso. Methods: Cross-sectional study with 236 social contacts of multibacillary leprosy from public schools and residents in Cuiabá (Mato Grosso) in 2018. The sources of information were interviews and nasal swab tests for molecular analysis by polymerase chain reaction - PCR. For the prevalence ratio estimates, crude and adjusted analyses were performed using robust Poisson regression and their respective confidence intervals (95% CI). The ArcGIS 9.1 software was used for the geographic distribution analyses. Results: The prevalence of detection of M. leprae in social contacts was 14%. A total of 63.6% of the schools surveyed had 5.1% to 50% of the social contacts of leprosy with positive PCR. The analysis of the geographic distribution in the neighborhoods showed a high prevalence of infection, being higher than 50% in some localities. The highest proportion of positive results occurred in the northern region of the city and from a precarious socioeconomic class. Conclusion: The results showed a high prevalence of detection of M. leprae among social contacts in areas with poor socioeconomic conditions. In these regions, there is a greater risk of

Perfil sociodemográfico, clínico e geoespacial de casos novos de hanseníase diagnosticados no Instituto Lauro de Souza Lima, Bauru, São Paulo, entre 2015 e 2019 / Sociodemographic, clinical and geospatial profile of new leprosy cases diagnosed at Institute Lauro de Souza Lima, Bauru, São Paulo, between 2015 and 2019

Embora o Brasil venha apresentando uma redução considerável no número de casos novos de hanseníase, alguns estudos têm demonstrado transmissão ativa mesmo em áreas não endêmicas, como o estado de São Paulo. Diante disso, investigamos o perfil sociodemográfico, clínico e geoespacial dos casos novos de hanseníase diagnosticados entre 2015 e 2019 no Instituto Lauro de Souza Lima (ILSL), um centro de referência localizado no município de Bauru, interior do estado de São Paulo. Foram diagnosticados 177 novos casos de hanseníase nesse período, sendo 61,6% dos pacientes naturais do estado. A maioria dos indivíduos era do sexo masculino (59,9%) e a faixa etária mais prevalente foi de 60 a 69 anos; 79,1% se autodeclaravam brancos e 65,6% possuíam pouca ou nenhuma escolaridade. A forma clínica dimorfa foi a mais frequente (42,4%), a baciloscopia foi positiva em 38,4% dos pacientes (49,0% entre o sexo masculino e 22,5% entre o sexo feminino) e 49,0% dos pacientes possuíam incapacidades no diagnóstico. O georreferenciamento, realizado para os casos oriundos do município de Bauru (n = 31), revelou que a maioria dos pacientes residia em regiões com elevado nível de vulnerabilidade social. O perfil dos pacientes atendidos no ILSL apontou para predominância de homens adultos ou idosos com baixa escolaridade, multibacilares, apresentando incapacidades físicas e longo tempo de sintomas. Em conjunto, nossos dados sugerem atraso no diagnóstico que pode contribuir para a manutenção da transmissão da hanseníase mesmo numa região não endêmica.(AU)

Although Brazil has shown a considerable reduction in the number of new cases of leprosy, some studies have shown active transmission even in non-endemic areas, such as São Paulo state. Considering this, we investigated the sociodemographic, clinical and geospatial profile of new cases of leprosy diagnosed between 2015 and 2019 at the Lauro de Souza Lima Institute (ILSL) a reference center localized in Bauru, a municipality in the interior of São Paulo state. A total of 177 new cases of leprosy were diagnosed in this period, with 61.6% of the patients born in the state. The majority of the individuals was male (59.9%), the most prevalent age group was 60 to 69 years old, 79.1% declared themselves white color/race and 65.6% had little or no schooling. The borderline form of leprosy was the most frequent (42.4%), slit skin smear was positive in 38.4% of patients (49.0% among men and 22.5% among women) and 49.0% had disabilities at diagnosis. Georeferencing, performed for cases from the municipality of Bauru (n = 31), revealed that most patients lived in regions with a high level of social vulnerability. The profile of leprosy new cases found at ILSL pointed to a predominance of adult or elderly men with low education, multibacillary, presenting physical disabilities and a long time of symptoms. Altogether, our data suggests a delay in diagnosis that may contribute to the maintenance of leprosy transmission even in a non-endemic region.(AU)

Tuberculosis associated factors caused by Mycobacterium tuberculosis of the RDRio genotype

BACKGROUND Tuberculosis (TB) continues to be a disease that affects many countries around the world, including Brazil. Recently, a subtype of Latin American-Mediterranean family strain was identified and characterised by RDRio. The strain has been associated with different characteristics of the disease. OBJECTIVES In the present study we investigated the association of epidemiological, clinical, radiological and bacteriological variables with pulmonary tuberculosis caused by RDRioMycobacterium tuberculosis strain in large regions of São Paulo. METHODS We conducted a cross-sectional study in 530 patients with pulmonary tuberculosis, diagnosed using sputum culture, from two regions of the São Paulo state in Brazil. The samples were brought to São Paulo reference laboratories for epidemiological, clinical, radiological and bacteriological analyses, and the data were obtained from a TB notification system. RDRio genotyping and Spoligotyping of the samples were performed. For the analysis of the categorical variables we used the chi-square test or the Fisher’s exact test, and for the continuous variables, the Mann-Whitney test. In addition, a logistic regression was used for multivariate analysis. Differences with p < 0.05 were considered significant. FINDINGS The RDRio deletion was identified in 152 (28.7%) samples. In the univariate analysis, both the age groups above 25 years and alcohol consumption were associated with the RDRio deletion. The multivariate analysis confirmed the association of the RDRio deletion with the age groups: 25-35 years old [OR: 2.28 (1.02-5.07; p = 0.04)] and 36-60 years old (OR: 2.36 (1.11-5.05); p = 0.03], and also with alcohol consumption [OR: 1.63 (1.05-2.54); p = 0,03]. MAIN CONCLUSIONS In this study, we identified new factors associated with the M. tuberculosis of the RDRio deletion strains infection.

Clinical and epidemiological profiles of individuals with drug-resistant tuberculosis

Drug-resistant tuberculosis (TB) is a growing global threat. Approximately 450,000 people developed multidrug-resistant TB worldwide in 2012 and an estimated 170,000 people died from the disease. This paper describes the sociodemographic, clinical-epidemiological and bacteriological aspects of TB and correlates these features with the distribution of anti-TB drug resistance. Mycobacterium tuberculosis (MT) cultures and drug susceptibility testing were performed according to the BACTEC MGIT 960 method. The results demonstrated that MT strains from individuals who received treatment for TB and people who were infected with human immunodeficiency virus were more resistant to TB drugs compared to other individuals (p < 0.05). Approximately half of the individuals received supervised treatment, but most drug-resistant cases were positive for pulmonary TB and exhibited positive acid-fast bacilli smears, which are complicating factors for TB control programs. Primary healthcare is the ideal level for early disease detection, but tertiary healthcare is the most common entry point for patients into the system. These factors require special attention from healthcare managers and professionals to effectively control and monitor the spread of TB drug-resistant cases.

Genotyping of Mycobacterium leprae present on Ziehl-Neelsen-stained microscopic slides and in skin biopsy samples from leprosy patients in different geographic regions of Brazil

We analysed 16 variable number tandem repeats (VNTR) and three single-nucleotide polymorphisms (SNP) in Mycobacterium leprae present on 115 Ziehl-Neelsen (Z-N)-stained slides and in 51 skin biopsy samples derived from leprosy patients from Ceará (n = 23), Pernambuco (n = 41), Rio de Janeiro (n = 22) and Rondônia (RO) (n = 78). All skin biopsies yielded SNP-based genotypes, while 48 of the samples (94.1%) yielded complete VNTR genotypes. We evaluated two procedures for extracting M. leprae DNA from Z-N-stained slides: the first including Chelex and the other combining proteinase and sodium dodecyl sulfate. Of the 76 samples processed using the first procedure, 30.2% were positive for 16 or 15 VNTRs, whereas of the 39 samples processed using the second procedure, 28.2% yielded genotypes defined by at least 10 VNTRs. Combined VNTR and SNP analysis revealed large variability in genotypes, but a high prevalence of SNP genotype 4 in the Northeast Region of Brazil. Our observation of two samples from RO with an identical genotype and seven groups with similar genotypes, including four derived from residents of the same state or region, suggest a tendency to form groups according to the origin of the isolates. This study demonstrates the existence of geographically related M. leprae genotypes and that Z-N-stained slides are an alternative source for M. leprae genotyping.

Drug resistance and genotypes of strains of Mycobacterium tuberculosis isolated from human immunodeficiency virus-infected and non-infected tuberculosis patients in Bauru, São Paulo, Brazil.

Little is known about transmission and drug resistance of tuberculosis (TB) in Bauru, State of S o Paulo. The objective of this study was to evaluate risk factors for transmission of Mycobacterium tuberculosis strains in this area. Strains were collected from patients attended at ambulatory services in the region and susceptibility towards the main first line antibiotics was determined and fingerprinting performed. A total of 57 strains were submitted to susceptibility testing: 23 (42.6%) were resistant to at least one drug while 3 (13%) were resistant against both rifampicin and isoniazide. Resistant strains had been isolated from patients that had not (n = 13) or had (n = 9) previously been submitted to anti-TB treatment, demonstrating a preoccupying high level of primary resistance in the context of the study. All strains were submitted to IS6110 restriction fragment length polymorphism (IS6110-RFLP) and double repetitive element PCR (DRE-PCR). Using IS6110-RFLP, 26.3% of the strains were clustered and one cluster of 3 patients included 2 HIV-infected individuals that had been hospitalized together during 16 days; clustering of strains of patients from the hospital was however not higher than that of patients attended at health posts. According to DRE-PCR, 55.3% belonged to a cluster, confirming the larger discriminatory power of IS6110-RFLP when compared to DRE-PCR, that should therefore be used as a screening procedure only. No clinical, epidemiological or microbiological characteristics were associated with clustering so risk factors for transmission of TB could not be defined in the present study.

Drug resistance and genotypes of strains of Mycobacterium tuberculosis isolated from human immunodeficiency virus-infected and non-infected tuberculosis patients in Bauru, São Paulo, Brazil

Little is known about transmission and drug resistance of tuberculosis (TB) in Bauru, State of São Paulo. The objective of this study was to evaluate risk factors for transmission of Mycobacterium tuberculosis strains in this area. Strains were collected from patients attended at ambulatory services in the region and susceptibility towards the main first line antibiotics was determined and fingerprinting performed. A total of 57 strains were submitted to susceptibility testing: 23 (42.6 percent) were resistant to at least one drug while 3 (13 percent) were resistant against both rifampicin and isoniazide. Resistant strains had been isolated from patients that had not (n = 13) or had (n = 9) previously been submitted to anti-TB treatment, demonstrating a preoccupying high level of primary resistance in the context of the study. All strains were submitted to IS6110 restriction fragment length polymorphism (IS6110-RFLP) and double repetitive element PCR (DRE-PCR). Using IS6110-RFLP, 26.3 percent of the strains were clustered and one cluster of 3 patients included 2 HIV-infected individuals that had been hospitalized together during 16 days; clustering of strains of patients from the hospital was however not higher than that of patients attended at health posts. According to DRE-PCR, 55.3 percent belonged to a cluster, confirming the larger discriminatory power of IS6110-RFLP when compared to DRE-PCR, that should therefore be used as a screening procedure only. No clinical, epidemiological or microbiological characteristics were associated with clustering so risk factors for transmission of TB could not be defined in the present study

Hanseníase experimental murina: inoculaçäo do Mycobaterium leprae via intranasal / Murine experimental hansen's disease: intranasal inoculation of the mycobacterium leprae

Considerando as vias aéreas superiores como a mais provável porta de entrada do M.leprae no organismo, no presente estudo avaliou-se o comportamento do bacilo inoculado experimentalmente via intranasal. Assim, camondongos suiços foram inoculados por instilaçäo nasal com M.leprae e sacrificados em diferentes períodos de tempo. Em cada cada sacrifício os pulmöes foram removidos e submetidos ao lavado broncoalveolar (LBA) e análise histopatológica. O LBA foi avaliado quanto ao número de bacilos recuperados e número total e diferencial de células inflamatórias; foi ainda semeado em meios de cultivo Lowenstein-Jensen e Middlebrook 7H9 e 7H11. No LBA foram encontrados bacilos até o 6§ mês de inoculaçäo, näo houve crescimento de micobactérias nas culturas. O número total de células, linfócitos e neutrófilos do LBA obtido de camundongos infectados foi maior que o do grupo controle até o 6§ mês da experimentaçäo. A análise histopatológica revelou pequenos infiltrados celulares distribuídos pelo parênquima pulmonar e ao redor dos vasos até o 6§ mês de sacrifício; näo foram observadas lesöes de disseminaçäo. Os resultados obtidos revelam que a inoculaçäo de M. leprae, via intranasal, em camundongos Suíços, näo levou ao desenvolvimento da doença nem a multiplicaçäo dos bacilos; assim estudos aidcionais envolvendo outras linhagens de camundongos poderäo ser úteis para determinar a importância da via intranasal na infecçäo hansênica