PubMed · 4899392
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E I Kozlova, L I Vorob'eva, Z A Arkad'eva, L I Rozanova, G Ia Dzhavakhiia. [Microorganisms oxidizing methane].. https://pubmed.ncbi.nlm.nih.gov/4899392/
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Various thermophilic bacteria were analyzed by Southern hybridization analysis using oligonucleotide probes coding for the pyruvate phosphate dikinase (PPDK) gene from Clostridium symbiosum, and positive hybridization signals were observed in the chromosomal DNAs from Microbispora rosea subsp. aerata (IFO 14047). PPDK activity was detected in lactose induced cells and the enzyme was purified to homogeneity. The molecular mass of PPDK was estimated to be 230000 by gel filtration chromatography and 91000 by SDS-PAGE, suggesting that PPDK is a dimeric enzyme. This enzyme was specific for adenine nucleotide and the apparent Km values for AMP, PPi, and phosphoenolpyruvate were 5, 38, and 280 microM, respectively. It was stable in the pH range 6 to 11, and retained 80% activity after 60 min heat treatment at 60 degrees C. We cloned the PPDK gene from M. rosea. It consists of 878 amino acids with a molecular mass of 95514. Sequence comparison indicates around 50% similarity with other PPDKs and it has all the highly conserved regions of the related enzymes. We expressed the PPDK gene in Escherichia coli and obtained enzymatically active protein.
This study investigated the prevalence of nim genes (proposed to encode a 5-nitroimidazole resistance product) in 64 anaerobic/facultative anaerobic bacteria. Employing universal nim gene primers, 458-bp amplified fragments were recorded as presumptive positives in 22/64 strains at an annealing temperature of 52 degrees C and 15/64 strains at 62 degrees C, of which seven were propionibacteria. DNA sequencing confirmed the presence of nimA genes in Propionibacterium spp. (five strains), Actinomyces odontolyticus (one strain), Prevotella bivia (one strain) and Clostridium bifermentans (one strain) and nimB genes from five strains of Bacteroides fragilis. nimA genes were predominant in propionibacteria indicating a potential nimA gene source in anaerobic environments.
A review of the literature on pelvic actinomycosis reveals that actinomycetes normally reside in the female genital tract. Therefore the identification of actinomycetes in the vagina or cervix by any laboratory technique, including Papanicolaou smears with specific immunofluorescence or culture, is not diagnostic of any disease and is not predictive of any disease. The evidence strongly suggests that removal of the intrauterine contraceptive device of a patient with a positive culture is not necessary and that, in the absence of evidence for pelvic infection, antibiotics are not required. Pelvic actinomycosis is a rare disease whose pathogenesis is poorly understood.