Species composition and growth-temperature characteristics of coliforms in relation to their sources.

Abstract

Species composition and growth-temperature characteristics of coliforms isolated from several types of environmental samples were investigated. It was possible to divide these isolates into eight distinct groups, six species groups and two unidentified, on the basis of their biochemical properties. The isolates included in the unidentified groups, giving IMViC reactions of --+ + and -+ -+, were tentatively termed "typical psychrotrophic coliform (TPC)" bacteria because of their ability to grow at 10. The TPC bacteria and Citrobacter freundii constituted the normal coliform flora of mountain soil and stream water samples. In contrast, Escherichia toll and Klebsiella pneumoniae were major predominant coliforms in polluted river water and sewage samples, the former being most common in human feces samples. In testing the growth response at different temperatures, the isolates of E. toll and the TPC bacteria showed relatively constant temperature preferences regardless of origin, whereas those of other coliform members gave varied results dependent upon their sources. The results provided circumstantial evidence that population densities of coliforms able to grow in EC broth at 43° and above but not in ordinary nutrient broth at 5° within 7 days of incubation in the environment are directly proportional to the degree of potential fecal contamination.The coliform bacteria are well established as indicators of hazardous fecal contamination of water and food (1, 2). Apart from Escherichia coli, a member of this group, these bacteria occur frequently in areas apparently free from obvious fecal contamination, although all coliforms were once thought of as being of fecal origin (3). Thus, the sanitary significance of coliforms not related to fecal sources has been and still is of major concern, with much interest being directed

Shortcut of the photosynthetic electron transfer in a mutant lacking the reaction center‐bound cytochrome subunit by gene disruption in a purple bacterium, Rubrivivax gelatinosus

“…Amplification of the DNA fragment containing pufC was performed using polymerase chain reaction (PCR) method as described in [30]. One of the primers had a sequence, 5'-GCCCAGCTGTT-CTGGGTCGG-3', the motif of which is seen at the 3' portion of pufM (at position -233 from pufC).…”

Habitat Association ofKlebsiellaSpecies

“…Although most of the human-associated nosocomial Klebsiella are likely to be K. pneumoniae or K. oxytoca, a significant percentage of the hospital environment/nonclinical Klebsiella may not be. Reported variations in Klebsiella response to temperature and survival in surface waters 53,57 and on hospital surfaces including hands 11,12 may also be due to the presence of several different Klebsiella spp. with varying growth ranges and nutritional capabilities.…”

Processamento mínimo de abóbora (Cucurbita moschata Duch.): alterações fisiológicas, qualitativas e microbiológicas.

“…De acordo com a Resolução RDC n o 12 de 02/01/2001, da Agência Nacional de Vigilância Sanitária (ANVISA) que pertence ao Ministério da Saúde, a legislação sanitária de alimentos exige, para hortaliças in natura, a ausência da Salmonella (em 25g da amostra) e admite, no máximo, 10 2 NMP (número mais provável) de coliformes fecais/g de produto para a preservação da saúde pública. Hiraishi & Horie (1982) afirmam que os coliformes são bons indicadores de contaminação fecal em alimentos. De acordo com a Internacional Commission on Microbiological Specifications for Foods -ICMSF (1978), a presença de coliformes em alimentos indica manipulação inadequada durante o processamento, uso inadequado de equipamentos em más condições sanitárias ou ainda utilização de matéria-prima contaminada.…”