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At least 19 recordsLinked to original sources
PubMed1999

Growth rates of mesophilic bacteria, aerobic psychrotrophic bacteria, and lactic acid bacteria in low-dose-irradiated pork.

Frozen pork patties, thawed overnight at 0 degrees C or temperature abused through storage at 15 degrees C for 24 h, were packaged using both vacuum and air packaging methods. Immediately after packaging, both sets of patties were irradiated at 0, 0.5, 1, and 2 kGy. All the samples were stored at 2 degrees C and were analyzed for populations of mesophilic, psychrotrophic, and lactic acid bacteria every 3 days for 30 days. By using a mesophilic population of 10(7) cells/g as a criteria for spoilage, fresh pork patties receiving a dose of 0 kGy had shelf lives of 11 and 16 days with air and vacuum packaging methods, respectively, whereas temperature-abused patties had a shelf life of 7 days with both air and vacuum packaging methods. Both fresh and abused patties that received a dose of 2 kGy had shelf lives that were greater than 30 days at 2 degrees C with both air and vacuum packaging methods. Descriptive models based on the Gompertz equation for mesophilic, psychrotrophic, and lactic acid bacteria were developed, and the generation time and lag-phase duration for each bacterial population were calculated.

Animals↗
PubMed1991

Molybdenum-dependent degradation of quinoline by Pseudomonas putida Chin IK and other aerobic bacteria.

Eighteen different aerobic bacteria were isolated which utilized quinoline as sole source of carbon, nitrogen, and energy. Attempts were unsuccessful at isolating anaerobic quinoline-degrading bacteria. The optimal concentration of quinoline for growth was in the range of 2.5 to 5 mM. Some organisms excreted 2-hydroxyquinoline as the first intermediate. Hydroxylation of quinoline was catalyzed by a dehydrogenase which was induced in the presence of quinoline or 2-hydroxyquinoline. Quinoline dehydrogenase activity was dependent on the availability of molybdate in the growth medium. Growth on quinoline was inhibited by tungstate, an antagonist of molybdate. Partially purified quinoline dehydrogenase from Pseudomonas putida Chin IK indicated the presence of flavin, iron-sulfur centers, and molybdenum-binding pterin. Mr of quinoline dehydrogenase was about 300 kDa in all isolates investigated.

Bacteria, Aerobic↗
PubMed1992

Critical assessment of blood culture techniques: analysis of recovery of obligate and facultative anaerobes, strict aerobic bacteria, and fungi in aerobic and anaerobic blood culture bottles.

Recent reports have documented a decrease in anaerobic bacteremias and have questioned the need for routine anaerobic blood cultures. At the same time, we and others have noted an increase in fungal bloodstream infections. In this two-part study, we first compared recoveries of obligate anaerobic bacteria with those of fungi over a 13-year period and then examined the recoveries of all bacteria and fungi in aerobic and anaerobic blood culture bottles during a 12-month period. During the 13-year period, the number of patients with anaerobic bacteremia remained relatively constant (average, 39 patients per year), while the incidence of fungemia steadily increased, from 12 patients in 1978 to 117 patients in 1990. Of the 1,090 anaerobic isolates, 55.1 and 90.2% were recovered in aerobic and anaerobic bottles, respectively, compared with 98.6 and 37.0% of the 2,582 fungi. During the 12-month period of evaluation, 2,980 bacteria and fungi were recovered in cultures collected from 1,555 patients. Overall, 21.1% more organisms were recovered in aerobic bottles than in anaerobic bottles, including significantly more Staphylococcus species; gram-positive aerobic bacilli; Escherichia, Enterobacter, Pseudomonas, Xanthomonas, and Acinetobacter species; miscellaneous gram-negative bacilli; and yeasts. Only anaerobic gram-negative bacilli and non-spore-forming gram-positive bacilli were isolated more commonly in anaerobic bottles. These data support the concepts that bacteremia caused by obligate anaerobic bacteria is decreasing relative to sepsis caused by other bacteria and fungi and that the routine use of unvented anaerobic blood culture bottles reduces the recovery of common aerobic bloodstream pathogens.

Bacteremia↗
PubMed1998

Biology of moderately halophilic aerobic bacteria.

The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms. The property of halophilism is widespread within the bacterial domain. Bacterial halophiles are abundant in environments such as salt lakes, saline soils, and salted food products. Most species keep their intracellular ionic concentrations at low levels while synthesizing or accumulating organic solutes to provide osmotic equilibrium of the cytoplasm with the surrounding medium. Complex mechanisms of adjustment of the intracellular environments and the properties of the cytoplasmic membrane enable rapid adaptation to changes in the salt concentration of the environment. Approaches to the study of genetic processes have recently been developed for several moderate halophiles, opening the way toward an understanding of haloadaptation at the molecular level. The new information obtained is also expected to contribute to the development of novel biotechnological uses for these organisms.

Adaptation, Biological↗
PubMed1992

(An)aerobic bacteria found in secondary-cataract material. A SEM/TEM study.

Twenty four patients, who had marked reduction of vision due to secondary-cataract developed after an ECCE, were treated by surgical cleaning of the posterior lens capsule. During this procedure globular secondary-cataract material was removed and collected for morphological examination by SEM and TEM. Fragments of various sizes and shapes, including some with a 'golf ball' structure, were seen; these closely resembled particles frequently found in cataractous lenses. In addition, in 18 patients micro-organisms were found: rod-shaped bacteria, cocci, and in 2 cases yeasts. These findings were the more remarkable because these were clinically quiet eyes with no signs of intra-ocular inflammation and cultures have been persistently negative. We imagine that these bacteria must have entered the eye during the cataract extraction and have settled there without causing an infection.

Bacteria, Aerobic↗
PubMed1983

Activity of imipenem on aerobic bacteria.

Imipenem is a new carbapenem antibiotic with a broad spectrum of activity on Gram-positive and Gram-negative bacteria. It is a potent inhibitor of plasmid- and chromosomally-mediated beta-lactamases. The purpose of this study was to evaluate the in vitro activity of imipenem on clinical isolates classified according to their susceptibility to beta-lactam antibiotics. On penicillin G-susceptible bacteria, imipenem is comparable to penicillin. On streptococci, pneumococci, Staphylococcus aureus and Listeria the MICs were 0.02 to 0.06 mg/l. On gonococci, MICs were 0.04 to 0.25 mg/l. Gram-negative bacteria susceptible to beta-lactam antibiotics or naturally resistant to certain of them (e.g. Klebsiella pneumoniae resistant to ampicillin and carbenicillin) were highly susceptible to imipenem with MICs from 0.06 to 0.5 mg/l. It was slightly less active on Haemophilus influenzae, compared to ampicillin. On beta-lactam-resistant bacteria, imipenem maintained a remarkable activity. For penicillin-resistant pneumococci (MIC 16 mg/l) the imipenem MIC was 1 mg/l. Imipenem was equally effective on beta-lactamase-producing and non-producing Haemophilus influenzae and gonococci. Among 12 Nocardia asteroides tested, 11 had MIC less than 1 mg/l. When tested at 30 degrees, the MIC of imipenem for oxacillin-resistant Staphylococcus aureus ranged from 8 to 64 mg/l in contrast to 0.03 to 0.06 mg/l for oxacillin-sensitive isolates. Eighteen strains of enterococci (17 faecium, 2 faecalis) resistant to ampicillin (MIC 128 mg/l) were more resistant to imipenem (MIC 16 to 256 mg/l). Imipenem was very active on beta-lactam-resistant Gram-negative bacteria, including multiply-resistant Salmonella typhi., with MICs in a range from 0.06 to 4 mg/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
PubMed1997

In-vitro activity of trovafloxacin against sensitive and resistant aerobic bacteria using the standard microdilution broth method and Etest.

A comparison of MICs of trovafloxacin (CP-99,219) determined by the standard microdilution broth method versus the Etest was performed for multiple strains of Gram-positive and Gram-negative bacteria. A comparison was also made of the in-vitro activity of trovafloxacin versus ciprofloxacin and ofloxacin. The MIC50 and MIC90 were determined by both methods for each species tested. The Etest resulted in MICs one to two dilutions higher than the microdilution broth method. Trovafloxacin was the most active agent against Gram-positive organisms. Ciprofloxacin was the most active agent against Citrobacter freundii, Proteus mirabilis, Proteus vulgaris, Morganella morganii and Serratia marcescens, while trovafloxacin had equal or greater activity compared with ciprofloxacin and ofloxacin against the other Gram-negative organisms tested. Overall, ofloxacin was the least active agent tested. In addition, the in-vitro activity of trovafloxacin or ciprofloxacin in combination with ampicillin/sulbactam, gentamicin or vancomycin was evaluated. The combination of trovafloxacin and gentamicin was synergic against two of 20 Enterococcus faecium isolates, the combination of trovafloxacin and ampicillin/sulbactam was synergic against two of 24 Enterococcus faecalis isolates, and the combination of ciprofloxacin and gentamicin was synergic against one of 25 Stenotrophomonas maltophilia isolates. All other antibiotic combinations resulted in an additive or indifferent effect.

Ampicillin↗
PubMedDate not supplied

Evaluation of Petrifilm method for enumerating aerobic bacteria in Crottin goat cheese.

The Petrifilm Aerobic Count Plate (ACP) developed by 3M laboratories, is a ready-to-use culture medium system, useful for the enumeration of aerobic bacteria in food. Petrifilm was compared with a standard method in several different food products with satisfactory results. However, many studies showed that bacterial counts in Petrifilm were significantly lower than those obtained with conventional methods in fermented food. The purpose of this study was to compare the Petrifilm method for enumerating aerobic bacteria with a conventional method (PCA) in Crottin goat's cheese. Thirty samples were used for the colony count. The mean count and standard deviation were 7.18 +/- 1.17 log CFU g(-1) on PCA and 7.11 +/- 1.05 log CFU g(-1) on Petrifilm. Analysis of variance revealed no significant differences between both methods (t = 1.33, P = 0.193). The Pearson correlation coefficient (0.971, P = 0.0001) indicated a strong linear relationship between the Petrifilm and the standard method. The results showed that Petrifilm is suitable and a convenient alternative to this standard method for the enumeration of aerobic flora in goat soft cheese.

Aerobiosis↗
PubMed1982

Isolation of aerobic bacteria from the placenta.

Cultures for aerobic bacteria were prepared from 353 placentas. Specimens were taken from the chorion after removing the amnion. The specimens were immersed into Stuart transport medium. Microscopic examination of the placenta and cultures from the throat and ear of newborns were also done. The rate of positive bacterial cultures was 16%. Chorioamnionitis was found in 15%. The proportion of chorioamnionitis caused by aerobic bacteria was 44%. The rate of positive bacterial cultures from the placenta in the group of newborns with clinical signs of intrauterine infection was 63%. Bacteria can be present on the chorionic plate without any histological evidence of chorioamnionitis. Bacteriological examination of the placenta is therefore mandatory when amniotic fluid infection is suspected.

Amniotic Fluid↗
PubMed1979

Distribution of aerobic bacteria which contain bacteriochlorophyll a.

Sixteen strains of aerobic bacteria which contain bacteriochlorophyll a were isolated from the samples collected in aerobic marine environments: thalli of Enteromorpha linza, Porphyra sp., Sargussum horneri; beach sand; and the surface seawater from Aburatsubo Inlet. When they occurred, their proportions among the aerobic heterotrophic populations ranged from 0.9 to 1.1% in the seaweed samples and from 1.2 to 6.3% in the beach sand samples and were 0.9% in the seawater sample. The results suggested that the aerobic photopigmented bacteria widely inhabit aerobic marine environments.

Journal Article↗
PubMed1999

Aerobic bacteria and solids in a three-tank, two-pass, counterflow scalder.

Scald water and whole carcass rinse samples were collected on 9 different d in a commercial broiler processing plant operating adjacent lines that processed birds from the same flock simultaneously. A conventional, single-tank, two-pass scalder was installed on one line and the other line had a three-tank, two-pass, counterflow scalder in which water mixed across the two lines of carcasses within each tank. Water samples from the turn around point in each tank were analyzed for aerobic bacteria and suspended solids. At the same time that water samples were taken, six carcasses were removed from the processing line immediately after feather removal and rinsed in 100 mL of phosphate-buffered saline; recovered rinse solution was analyzed for aerobic bacteria using a most probable number procedure. Estimated numbers of aerobic bacteria were significantly reduced in the third tank of the counterflow scalder compared to the second tank, or compared to the single tank of the conventional scalder. Despite the differences in aerobic bacteria between scald tanks, numbers of aerobic bacteria in carcass rinses were not affected by scalder design. Organic and total solids were significantly reduced in the third tank of the counterflow scalder compared to the first and second tanks, and in the third tank of the counterflow scalder compared to the conventional scalder. Solids in the third (final) tank of the counterflow scalder were reduced by about 70% compared to the conventional scalder.

Animals↗