A total of 958 samples of raw fish, fish products and "frutti di mare" were tested for staphylococci. Among 153 strains isolated and subjected to identification the most frequently present were: S. aureus, S. warneri, S. hominis and S. sciuri. These species stated for 46.4; 20.9; 7.2 and 5.2 percent of the total number of identified staphylococci species, respectively. Atypical coagulase-negative S. aureus represented 11.3 percent of identified strains of this species. With coagulase-negative staphylococci taken into account, presence of staphylococci was confirmed in 69.8 percent of the 275 samples tested, while contamination with coagulase-positive staphylococci was confirmed in 24.7 percent of them

Two hundred samples of foodstuffs and water were examined for the presence of Enterococcus sp., of which 105 were identified as positive. Sixty samples of foodstuffs and water were examined for the presence of Staphylococcus sp., of which 48 were identified as positive. The isolated strains were identified and, based on their generic attributes, they were ranked to genus Enterococcus and Staphylococcus. For sorting, a STAPHYtest 16, API Staph and EN-COCCUS tests were used. The isolates were further subjected to screening of susceptibility to antibiotics, a broth microdilution method was applied.

Doutoramento em Engenharia Alimentar. Universidade de Lisboa, Instituto Superior de Agronomia | The main objective of this study was, to evaluate the microbiological quality and safety of water and RTE foods sold on the streets of Maputo. For this, 83 RTE street food samples from 83 different vendors and 116 water samples from different sources were analyzed. Selected bacterial isolates were molecularly identified and characterized. High levels of unsatisfactory samples were found in both hot (76.7%) and cold (75%) foods. Based on staphylococcal counts, approximately 25% of the food samples were unsatisfactory/potentially hazardous. A high level of fecal contamination was detected in all types of water samples. In Escherichia coli isolates from food and water, the highest percentages of resistance were for the ß-lactams imipenem (35.5 and 39.3%, respectively) and ampicillin (39.3 and 46.4%, respectively). Multidrug resistance was observed in 31.3% of the isolates, being higher in water isolates (45.5%) than food isolates (19.2%). ESBL was the most frequent (57.7%) antibiotic resistance gene among those encoding β-lactamases, while tetA was the most frequent (50%) among non-β-lactamase genes. Furthermore, 73% of the multidrug-resistant E. coli isolates also had virulence genes. The most frequent virulence gene was sec (30.3%) followed by the hlb (24.2%) and sak and sed genes (12.5% each). Regarding the presence of antibiotic resistance genes in Staphylococcus, blaZ (penicillin resistance) was the most frequent (74.2%) followed by mecA (methicillin resistance) and vancA (vancomycin resistance) genes (43.9% and 42.4%, respectively. Staphylococcus isolates had a high ability to form biofilms on different materials and these biofilms were resistant to high concentrations of methicillin (32 g/ml). The results reported here show that water and food sold on the streets of Maputo, Mozambique, pose a potential risk to public health. | O principal objectivo deste estudo foi avaliar a qualidade microbiológica e a segurança da água e dos alimentos RTE vendidos nas ruas de Maputo. Para isso, foram analisadas 83 amostras de comida de rua RTE de 83 vendedores diferentes e 116 amostras de água de diferentes origens. Os isolados bacterianos selecionados foram identificados e caracterizados molecularmente. Foram encontrados elevados níveis de amostras insatisfatórias, tanto em alimentos quentes (76,7%) quanto em alimentos frios (75%). Com base na contagem de estafilococos, aproximadamente 25% das amostras de alimentos eram insatisfatórias/potencialmente perigosas. Foi encontrado um elevado nível de contaminação fecal em todos os tipos de amostras de água. Nos isolados de Escherichia coli provenientes de alimentos e água, as maiores percentagens de resistência foram para os ß-lactâmicos imipenem (35,5 e 39,3%, respectivamente) e ampicilina (39,3 e 46,4%, respectivamente). A multirresistência foi observada em 31,3% dos isolados, sendo maior nos isolados de água (45,5%) do que nos isolados de alimentos (19,2%). ESBL foi o gene para β-lactamases mais frequente (57,7%), enquanto tetA foi o mais frequente (50%) entre genes não β-lactamases. Além disso, 73% dos isolados de E. coli multirresistentes também tinham genes de virulência. O gene de virulência mais frequente foi sec (30,3%), seguido pelos genes hlb (24,2%) e sak e sed (12,5% cada). Em Staphylococcus, blaZ (resistência à penicilina) foi o gene mais frequente (74,2%), seguido pelos genes mecA e vancA (43,9% e 42,4%, respectivamente). Staphylococcus mostrou capacidade de formar biofilmes em diferentes materiais e esses biofilmes eram resistentes a elevadas concentrações de meticilina (32 g/ml). Os resultados aqui relatados mostram que a água e os alimentos vendidos nas ruas de Maputo, Moçambique, representam um risco potencial para a saúde pública. | N/A