Avaliação do potencial de formigas (Hymenoptera: formicidae) como vetores mecânicos de bactérias do gêneroSstaphylococcus no ambiente hospitalar.

In a hospital environment, these bacteria can be spread by insects such as ants, which are characterized by high adaptability to the urban environment. Staphylococcus is a leading cause of hospital infection. In Europe, Latin America, USA and Canada, the group of coagulase negative staphylococci (CoNS) is the second leading cause of these infections, according to SENTRY (antimicrobial surveillance program- EUA). In this study, we investigated the potential of ants (Hymenoptera: Formicidae) as vehicle mechanics of Staphylococcus bacteria in a public hospital, in Natal-RN. The ants were collected, day and night, from June 2007 to may 2008, in the following sectors: hospitals, laundry, kitchen, blood bank. The ants were identified according to the identification key of Bolton, 1997. For the analysis of staphylococci, the ants were incubated in broth Tryptic Soy Broth (TSB) for 24 hours at 35 º C and then incubated on Mannitol Salt Agar. The typical colonies of staphylococci incubated for 24 hours at 35 ° C in Tryptic Soy Agar for the characterization tests (Gram stain, catalase, susceptibility to bacitracin and free coagulase). The identification of CoNS was performed through biochemical tests: susceptibility to novobiocin, growth under anaerobic conditions, presence of urease, the ornithine decarboxylation and acid production from the sugars mannose, maltose, trehalose, mannitol and xylose. The antimicrobial susceptibility examined by disk-diffusion technique. The technique of Polymerase Chain Reaction was used to confirm the presence of mecA gene and the ability to produce biofilm was verified by testing in vitro using polystyrene inert surface, in samples of resistant staphylococci. Among 440 ants, 85 (19.1%) were carrying coagulase-negative staphylococci (CoNS) of the species Staphylococcus saprophyticus (17), Staphylococcus epidermidis (15), Staphylococcus xylosus (13), Staphylococcus hominis hominis (10), Staphylococcus lugdunensis (10), Staphylococcus warneri (6), Staphylococcus cohnii urealyticum (5), Staphylococcus haemolyticus (3), Staphylococcus simulans (3), Staphylococcus cohnii cohnii (2), and Staphylococcus capitis (1). No Staphylococcus aureus was found. Among the isolates, 30.58% showed resistance to erythromycin. Two samples of CoNS (2.35%), obtained from the ant Tapinoma melanocephalum collected in the post-surgical female ward, S. Hominis hominis and S. lugdunensis harbored the mecA gene and were resistant to multiple antibiotics, and the specie S. hominis hominis even showed to be a biofilm producer. This study proves that ants act as carriers of multidrug-resistant coagulase-negative Staphylococci and biofilm producers and points to the risk of the spreading of pathogenic microorganisms by this insect in the hospital environment

Obtenção de sistemas multiparticulados de isoniazida revestidos com polímero de liberação entérica

Known for thousands of years, tuberculosis (TB) is the leading cause of mortality by a single infectious disease due to lack of patient adherence to available treatment regimens, the rising of multidrug resistant strains of TB (MDR-TB) and co-infection with HIV virus. Isoniazid and rifampicin are the most powerful bactericidal agents against M. tuberculosis. Because of that, this couple of drugs becomes unanimity in anti-TB treatment around the world. However, the rifampicin in acidic conditions in the stomach can be degraded rapidly, especially in the presence of isoniazid, which reduces the amount of available drug for absorption, as well as its bioavailability, contributing to the growing resistance to tuberculostatic drugs. Rifampicin is well absorbed in the stomach because of its high solubility between pH 1 and 2 and the gastric absorption of isoniazid is considered poor, therefore it is mostly intestinal. This work has as objective the development of gastro-resistant multiple-systems (granules and pellets) of isoniazid aiming to prevent the contact with rifampicin, with consequent degradation in acid stomach and modulate the release of isoniazid in the intestine. Granules of isoniazid were obtained by wet method using both alcoholic and aqueous solutions of PVP K-30 as aggregating and binder agent, at proportions of 5, 8 and 10%. The influence of the excipients (starch, cellulose or filler default) on the physical and technological properties of the granules was investigated. The pellets were produced by extrusionesferonization technique using isoniazid and microcrystalline cellulose MC 101 (at the proportion of 85:15) and aqueous solution of 1% Methocel as platelet. The pellets presented advantages over granular, such as: higher apparent density, smaller difference between apparent and compaction densities, smoother surface and, especially, smaller friability, and then were coated with an organic solution of Acrycoat L 100 ® in a fluidized bed. Different percentages of coating (15, 25 and 50%) were applied to the pellets which had their behavior evaluated in vitro by dissolution in acidic and basic medium. Rifampicin dissolution in the presence of uncoated and coated isoniazid pellets was evaluated too. The results indicate that the gastro resistance was only achieved with the greatest amount of coating and isoniazid is released successfully in basic step. The amount of rifampicin in the dissolution medium when the isoniazid pellets were not coated was lower than in the presence of enteric release pellets. Therefore, the polymer Acrycoat L 100 ® was efficient for coating with gastro-resistant function and can solve the problem of low bioavailability of rifampicin and help to reduce its dosage

Avaliação do potencial de formigas (Hymenoptera: formicidae) como vetores mecânicos de bactérias do gêneroSstaphylococcus no ambiente hospitalar.

In a hospital environment, these bacteria can be spread by insects such as ants, which are characterized by high adaptability to the urban environment. Staphylococcus is a leading cause of hospital infection. In Europe, Latin America, USA and Canada, the group of coagulase negative staphylococci (CoNS) is the second leading cause of these infections, according to SENTRY (antimicrobial surveillance program- EUA). In this study, we investigated the potential of ants (Hymenoptera: Formicidae) as vehicle mechanics of Staphylococcus bacteria in a public hospital, in Natal-RN. The ants were collected, day and night, from June 2007 to may 2008, in the following sectors: hospitals, laundry, kitchen, blood bank. The ants were identified according to the identification key of Bolton, 1997. For the analysis of staphylococci, the ants were incubated in broth Tryptic Soy Broth (TSB) for 24 hours at 35 º C and then incubated on Mannitol Salt Agar. The typical colonies of staphylococci incubated for 24 hours at 35 ° C in Tryptic Soy Agar for the characterization tests (Gram stain, catalase, susceptibility to bacitracin and free coagulase). The identification of CoNS was performed through biochemical tests: susceptibility to novobiocin, growth under anaerobic conditions, presence of urease, the ornithine decarboxylation and acid production from the sugars mannose, maltose, trehalose, mannitol and xylose. The antimicrobial susceptibility examined by disk-diffusion technique. The technique of Polymerase Chain Reaction was used to confirm the presence of mecA gene and the ability to produce biofilm was verified by testing in vitro using polystyrene inert surface, in samples of resistant staphylococci. Among 440 ants, 85 (19.1%) were carrying coagulase-negative staphylococci (CoNS) of the species Staphylococcus saprophyticus (17), Staphylococcus epidermidis (15), Staphylococcus xylosus (13), Staphylococcus hominis hominis (10), Staphylococcus lugdunensis (10), Staphylococcus warneri (6), Staphylococcus cohnii urealyticum (5), Staphylococcus haemolyticus (3), Staphylococcus simulans (3), Staphylococcus cohnii cohnii (2), and Staphylococcus capitis (1). No Staphylococcus aureus was found. Among the isolates, 30.58% showed resistance to erythromycin. Two samples of CoNS (2.35%), obtained from the ant Tapinoma melanocephalum collected in the post-surgical female ward, S. Hominis hominis and S. lugdunensis harbored the mecA gene and were resistant to multiple antibiotics, and the specie S. hominis hominis even showed to be a biofilm producer. This study proves that ants act as carriers of multidrug-resistant coagulase-negative Staphylococci and biofilm producers and points to the risk of the spreading of pathogenic microorganisms by this insect in the hospital environment