Microbiological aspects of an urban river used for unrestricted irrigation in the semi-arid region of north-east Brazil.

This study compared the behaviour of pathogenic bacteria (Salmonella and Listeria), faecal indicators (faecal coliforms FC and faecal streptococci FS), somatic coliphages and F-specific bacteriophages in an urban river contaminated with domestic sewage and surface run-off from agricultural and cattle grazing lands. The influence of physical and chemical parameters was also investigated as well as Salmonella and Listeria serotype diversity and drug resistance patterns. Faecal contamination was high (FC = 5 x 10(6) - 4 x 10(3) CFU/100 mL; FS = 4 x 10(5) - 2 x 10(2) CFU/100 mL) but decreased along the river by up to 99.5% following 47% reduction of BOD5 and 91% increase of DO, both associated with the self purification process. Somatic coliphages (6.9 x 10(5) - 1 x 10(3) PFU/100 mL) and F-specific bacteriophages (5.8 x 10(4) - 65 PFU/100 mL) behaved similarly with reductions of 99.85%. Salmonella and Listeria were isolated at all sampling points with highestfrequencies (91-100%) at those with sewage discharge and rural water run-off. The lowest value (35%) occurred at the end of the river where it was (a) wider and shallower, (b) it ran slower and was warmer (29-33 degrees C), (c) the pH was alkaline (8.2-9.9), (d) electrical conductivity (2,200-5,800 microS/cm) and DO (6-13 mg/L) were highest. Pathogen decline did not follow exactly FC and FS reduction patterns, while physical and chemical parameters apparently did not interfere with Salmonella and Listeria survival to the same extent as they did with FC and FS. Somatic coliphages and F-specific bacteriophages did not show more resistance than bacterial indicators. Catchment area contribution seemed to be more significant for pathogens than for indicators and rainy periods increased pathogenic isolation frequency. Five Salmonella serotypes and five serogroups were identified. S. hadar and serogroup E were predominant (50%); both are increasing in Brazil apparently from animal sources. Nearly 25% of Salmonella strains were resistant to at least one of twelve antimicrobials tested. Resistance to tetracycline was common (17%) followed by cefalotine (3%). Five Listeria serogroups were isolated and L. grayi (43%) and L. monocytogenes (9%) were present at all points. Listeria drug resistance rates were 100% for oxaciline followed by clindamicine (97%), tetracycline (34%) and vancomycin (32%). Both pathogenic bacterial strains presented resistance to the same drugs observed in humans and warm blood animals but the high number of sensitive strains and the low numbers of strains resistant to more than one drug was not expected because of the heavy anthropogenic impact in this basin.

River water quality improvement by natural and constructed wetland systems in the tropical semi-arid region of northeastern Brazil.

The efficiencies of a natural Typha spp wetland (Wn) formed on a river bed and its effluent treatment in a constructed wetland (Wc, subsurface horizontal flow) were investigated in northeastern Brazil (Paraiba State). The Wc system (12 tanks with stone gravel, 4.13 m2, 0.22 m3, 20 Typha spp rhizomes, m(-2) each, with 38, 29, and 19 mm x d(-1) hydraulic loadings, and 5, 7, and 10 days HRT) was fed daily with effluent from a Wn. Wn removal presented the highest values after Typha spp were cut during the 5th week. Removal values were (1st and 2nd periods or before and after cutting): 75% and 81% BOD5; 10-53% total phosphorus; 13%-55% ammonia; 89%-91% FC; 90-96% coliphages and bacteriophages. Wc removals increased with time with best results on 10 d HRT. Removals were also higher in the 2nd period: 74%-78% BOD5; 58%-82% ammonia; 90% FC; 94-98% FS; and 92%-96% coliphages and bacteriophages. Despite the high remaining values of FC (1.4 x 10(4) CFU/100 ml) and FX (4 x 10(3) CFU/100 ml), the removals were satisfactory and HRT dependent, suggesting a gradual optimization of the system with time. The Wc exhibited good efficiency for improving water quality from polluted river.

Influência das condiçöes higiênico-sanitárias no processo de beneficiamento de tilápias (Oreocrhomis niloticus) em filés congelados / Influence of the hygienic-sanitary conditions in the process of tilapia in frozen fillets

Foram analisadas 60 amostras de peixes coletadas ao longo da cadeia de produçäo de filés congelados em um frigorífico de uma fazenda de criaçäo de peixes, situada em Campina Grande-PB (Brasil). Os peixes recém-capturados apresentaram o valor mínimo para NMP de 3,0/g tanto para coliformes totais (CT) como para coliformes fecais (CF) e também para Escherichia coli. Para bactérias aeróbias mesófilas (CPP) esse valor mínimo foi de 0,3x10.000 UFC/g. As concentraçöes de Staphylococcus aureus flutuaram entre o valor Estimado de <10,0 a 10,6x100 UFC/g e Salmonella spp. esteve presente em 8,3 por cento das amostras. A contaminaçäo dos peixes foi crescente ao longo da cadeia de processamento atingindo valores nas amostras comercializadas de 2400,0 NMP/g tanto para CT como para CF como para E.coli, embora maiores valores tenham sido observados para os coliformes em amostras de filés näo congelados. Para CPP esses valores finais foram de 10.000,0 x10.000 UFC/g. Os resultados evidenciaram deficiências higiênicas por parte dos manipuladores na indústria, necessitando de melhorias em todo o processamento, principalmente, na filetagem e retirada da pele, etapas nas quais as amostras se apresentaram mais contaminadas por S. aureus.

Distribuição da microbiota anemófila em ambiente hospitalar (Campina Grande, PB) / Anemophilic microbiota distribuition in a hospital environment (Campina Grande, PB)

No ambiente hospitalar é frequente a presença de microrganismos oportunistas que ao infectar pacientes imunodeprimidos, idosos e crianças causam surtos hospitalares severos. Todavia, os microrganismos selecionados neste ambiente apresentam multi-resistência aos antimicrobianos de uso rotineiro, dificultando a antibioticoterapia. Neste trabalho foi avaliada a distribuição e a diversidade da microbiota anemófila de 15 salas de um hospital da rede privada (Campina Grande, PB), e analisando o padrão de resistência das bactérias isoladas. Os resultados de 4 coletas mostraram uma diversidade de 20 gêneros de fungos e 10 de bactérias (5 grupos de Gram-positivos e 5 de Gram-negativos). O centro cirúrgico, o berçário e a UTI-adulto foram os locais de maior contaminação. Penicillium spp, Cladosporium spp e FNE foram os fungos de maior frequência de isolamento. Dentre as bactérias, Staphylococcus aureus, oxacilina resistente esteve presente na maioria dos ambientes. Netilmicina e amicacina foram os antibióticos com maior sensibilidade e ampicilina com o menor. Recomenda-se intensificar a desinfecção e assepsia do hospital assim como investigar a relação entre as frequências de isolamento de microrganismos patogênicos e oportunistas com as condições climáticas.

Sensibilidade "in vitro" de Vibrio cholerae 01, de origem humana e ambiental, a produtos naturais e a antibióticos tradicionais / Sensitivity in vitro of Vibrio cholerae 01 from human and environmental, natural products and traditional antibiotics

Foi avaliada a sensibilidade "in vitro" de 43 cepas de Vibrio cholerae 01 (22 de origem humana e 21 ambientais) com relação a seis antibióticos usados na quimioprofilaxia da diarréia colérica (TET, ERI, CLO, AMP, SUT, NOR ), a cinco produtos naturais com atividade antimicrobiana (extratos de B. virgiloides, C. altissiana e P. sellowinus e óleos essenciais de C. citratus e C. limonum), e a duas imidas semi-sintéticas análogas de filantimidas. Todas as cepas foram sensíveis a TET, AMP, CLO. SUT e NOR. Apenas uma, de origem humana, foi resistente a ERI. Dos fitoterápicos, tiveram atividade antimicrobiana os óleos essenciais "in natura" e as duas imidas semi-sintéticas. O óleo de C. citratus inibiu o crescimento de todas as cepas com halos ≥16mm e o de C. limonum inibiu apenas 41% com halos médios de 10mm. A atividade antimicrobiana destes óleos é atribuída a seus constituintes químicos (pineno, E-citral, 7-citral, α-terpinemo, mirceno e citronela). As imidas apresentam forte atividade antimicrobiana em concentrações ≥12,3 µg/mL. Os extratos de B. virgiloides (leguminoseae), C. altissiana e P. sellowinus (Euphorbiaceae), apesar de apresentarem constituintes químicos como alcalóides, taninos, e óleos com propriedade antimicrobiana, não apresentaram atividade, provavelmente por terem maior efeito contra bactérias Gram positivas. Os resultados sugerem o possível emprego de produtos naturais como alternativos no tratamento da cólera.

The significance of hospitals as reservoirs for endemic multiresistant Salmonella typhimurium causing infection in urban Brazilian children.

To identify possible sources of multiply drug-resistant Salmonella typhimurium among children in São Paulo, Brazil, we reviewed records of 470 children who had visited eight outpatient clinics from March 1981 to May 1982 and of 28 children who had been admitted to one referral hospital between June and November of 1982, and we examined plasmid profiles of the Salmonella isolates by agarose-gel electrophoresis. S. typhimurium was identified in 37 of these children. Case-control studies showed that children with S. typhimurium infections were more likely to have been hospitalized before onset of diarrhea than were either age-matched children without diarrhea (P = .031) or age-matched children with nonbacterial diarrhea (P = .035). Four distinct plasmid profiles, each of which was temporally clustered, were identified in 20 (67%) of 30 S. typhimurium strains isolated from previously hospitalized children and in two (28%) of seven strains from children not previously hospitalized. Each of three of these four profiles was associated with a different hospital, results suggesting that multiresistant-S. typhimurium infections in São Paulo are often nosocomially acquired.