Ants' role (Hymenoptera: Formicidae) as potential vectors of mycobacteria dispersion / Comportamento de formigas (Hymenoptera: Formicidae) como vetores potenciais de dispersão de micobactérias

Ants are found worldwide playing an important environmental role. Some species are considered as agricultural pests and potential risk to human life and public health acting as pathogens carriers. Ants as Paratrechina longicornis and Camponotus spp. have been found inside hospitals. The aim of this study was the research of mycobacteria in 138 samples of ants (137 Paratrechina longicornis and only one Camponotus spp.) which got into the laboratories of tuberculosis diagnosis. These ants were suspended in sterile saline solution and inoculated into Petragnani and Stonebrink media, incubated at 37° C until 90 days and the isolates were identified as environmental mycobacteria (1 Mycobacterium fortuitum peregrinum, 1 Mycobacterium smegmatis) and 1 Mycobacterium tuberculosis complex. These results showed that ants should also act as mechanical vectors of mycobacteria dissemination in risk environments, reinforcing their significance in public health.

As formigas têm uma distribuição mundial e representam importante papel no ecossistema. Algumas espécies são consideradas pragas para a agricultura e um risco potencial à vida humana e à saúde pública veiculando mecanicamente agentes patogênicos. Formigas como Paratrechina longicornis e Camponotus spp. têm sido encontradas em ambientes hospitalares. O foco do presente estudo foi a identificação de micobactérias em 138 amostras de formigas (137 Paratrechina longicornis e apenas uma Camponotus sp.), que tiveram acesso a áreas de laboratórios de diagnóstico de tuberculose. Essas formigas foram suspensas em solução salina estéril que foi semeada em meios de Petragnani e Stonebrink, incubadas a 37º C por até 90 dias e as estirpes de micobactérias isoladas foram identificadas pelas técnicas clássicas como micobactérias ambientais (sendo 1 Mycobacterium smegmatis, 2 Mycobacterium fortuitum peregrinum e 1 Mycobacterium tuberculosis). Esses resultados mostram que as formigas podem também se constituir vetores de dispersão de micobactérias em ambientes de risco, reforçando sua importância em saúde pública.

ANTS ROLE (HYMENOPTERA: FORMICIDAE) AS POTENTIAL VECTORS OF MYCOBACTERIA DISPERSION

ABSTRACT Ants are found worldwide playing an important environmental role. Some species are considered as agricultural pests and potential risk to human life and public health acting as pathogens carriers. Ants as Paratrechina longicornis and Camponotus spp. have been found inside hospitals. The aim of this study was the research of mycobacteria in 138 samples of ants (137 Paratrechina longicornis and only one Camponotus spp.) which got into the laboratories of tuberculosis diagnosis. These ants were suspended in sterile saline solution and inoculated into Petragnani and Stonebrink media, incubated at 37° C until 90 days and the isolates were identified as environmental mycobacteria (1 Mycobacterium fortuitum peregrinum, 1 Mycobacterium smegmatis) and 1 Mycobacterium tuberculosis complex. These results showed that ants should also act as mechanical vectors of mycobacteria dissemination in risk environments, reinforcing their significance in public health.

RESUMO As formigas têm uma distribuição mundial e representam importante papel no ecossistema. Algumas espécies são consideradas pragas para a agricultura e um risco potencial à vida humana e à saúde pública veiculando mecanicamente agentes patogênicos. Formigas como Paratrechina longicornis e Camponotus spp. têm sido encontradas em ambientes hospitalares. O foco do presente estudo foi a identificação de micobactérias em 138 amostras de formigas (137 Paratrechina longicornis e apenas uma Camponotus sp.), que tiveram acesso a áreas de laboratórios de diagnóstico de tuberculose. Essas formigas foram suspensas em solução salina estéril que foi semeada em meios de Petragnani e Stonebrink, incubadas a 37º C por até 90 dias e as estirpes de micobactérias isoladas foram identificadas pelas técnicas clássicas como micobactérias ambientais (sendo 1 Mycobacterium smegmatis, 2 Mycobacterium fortuitum peregrinum e 1 Mycobacterium tuberculosis). Esses resultados mostram que as formigas podem também se constituir vetores de dispersão de micobactérias em ambientes de risco, reforçando sua importância em saúde pública.

Transmission of tuberculosis in an endemic urban setting in Brazil.

SETTING: Two out-patient facilities in São Paulo, Brazil. OBJECTIVE: To study the transmission pattern of tuberculosis (TB) among human immunodeficiency virus (HIV) infected and uninfected persons in a setting endemic for TB. DESIGN: A prospective study comparing HIV-seropositive and -seronegative TB patients identified consecutively between 1 March 1995 and 1 April 1997. The patients were stratified according to their Mycobacterium tuberculosis isolate IS6110 RFLP patterns. Risk factors were sought for infection with an RFLP cluster pattern strain, inferred to represent recent transmission. RESULTS: Fifty-eight (38%) of 151 HIV-seropositive patients and 36 (25%) of 142 HIV-seronegative patients were infected with M. tuberculosis isolates that belonged to cluster patterns (OR 1.84, 95% CI 1.08-3.13). Multidrug-resistant (MDR) strains were isolated from 19 patients, all of whom were HIV seropositive; 12 (63%) of these, and 46 (35%) of 132 drug-susceptible isolates had cluster patterns (OR 3.20, 95% CI 1.08-9.77). CONCLUSION: In a TB-endemic urban setting in Brazil, the proportion of cases resulting from recent transmission appears to be greater among HIV-seropositive than among HIV-seronegative patients. A large proportion of MDR-TB (63%) cases was caused by strains that had cluster RFLP patterns, suggesting recent transmission of already resistant organisms. This type of knowledge regarding TB transmission may help to improve locally appropriate TB control programs.