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PubMed2005

Antimicrobial susceptibility pattern of bacterial isolates from post-operative wound infections.

516 bacterial isolates were obtained from 502 pus samples, collected from post operative wound infections. Staphylococcus aureus (n=166) was the most frequently isolated bacteria followed by Escherichia coli (n=114), Pseudomonas aeruginosa (n=65), Acinetobacter (n=43), Klebsiella pneumoniae (n=29) and others. Majority of the isolates were resistant to ampicillin, ampicillin-clavulanic acid, cephelexin, cefuroxime, cefotaxime, fluoroquinolones and cotrimoxazole. Alarming antimicrobial resistance made it imperative that measures for control be taken with special emphasis on formulation and implementation of antibiotic policy.

Anti-Bacterial Agents↗

PubMed2004

The identification of genetically related bacterial isolates using pulsed field gel electrophoresis on nursing home units: a clinical experience.

OBJECTIVES: To describe a laboratory-based technique to track nursing home infections. DESIGN: Retrospective data analysis. SETTING: A 721-bed skilled care facility with 14 nursing units. PARTICIPANTS: Residents in a nursing home, average age 76+/-10, 78% male. MEASUREMENTS: Bacterial isolates were listed for each nursing unit. Clusters of identical species and antibiotic susceptibility were identified followed by pulsed-field gel electrophoresis (PFGE). If the genetic analysis yielded related strains, the director of nursing performed a clinical investigation. PFGE is available through reference laboratories at a cost of approximately 75 dollars/isolate. RESULTS: Twenty-four clinical clusters of phenotypically identical bacteria (species, antibiotic susceptibility) were identified. Fourteen included genetically related isolates. CONCLUSION: Approximately half of the phenotypically identical clusters contained genetically related isolates. The identification of genetically related bacterial isolates on nursing units by PFGE provides staff with a specific circumstance to review secretion precautions. Genetic analysis may also demonstrate that apparent clusters are unrelated.

Aged↗

PubMed2003

Resistance of bacterial isolates from poultry products to therapeutic veterinary antibiotics.

Bacterial isolates from poultry products were tested for their susceptibility to 10 antibiotics commonly used in the therapeutic treatment of poultry. Bacteria were isolated from fresh whole broiler carcasses or from cut-up meat samples (breast with or without skin, wings, and thighs) that were either fresh or stored at 4 or 13 degrees C (temperatures relevant to poultry-processing facilities). The Biolog system was used to identify isolates, and a broth dilution method was used to determine the antibiotic resistance properties of both these isolates and complementary cultures from the American Type Culture Collection. The antibiotics to which the most resistance was noted were penicillin G, sulfadimethoxine, and erythromycin; the antibiotic to which the least resistance was noted was enrofloxacin. Individual isolates exhibited resistances to as many as six antibiotics, with the most common resistance pattern involving the resistance of gram-negative bacteria to penicillin G, sulfadimethoxine, and erythromycin. Differences in resistance patterns were noted among 18 gram-positive and 7 gram-negative bacteria, and comparisons were made between species within the same genus. The data obtained in this study provide a useful reference for the species and resistance properties of bacteria found on various raw poultry products, either fresh or stored at temperatures and for times relevant to commercial processing, storage, and distribution. The results of this study show that resistance to antibiotics used for the therapeutic treatment of poultry occurs in bacteria in the processing environment.

Animals↗

PubMed1991

Penicillin amidohydrolase productivity of locally isolated bacterial species.

Penicillin amidohydrolase productivity of four locally isolated bacterial species is described. Organisms were identified as Escherichia coli, Pseudomonas aeruginosa, Sarcina lutea and Bacillus megaterium. Highest enzyme productivity of 3.2 U/mL with a corresponding dry cell mass of 4.5 g/L was recorded from S. lutea.

Bacillus megaterium↗

PubMed2000

In vitro activity of difloxacin against canine bacterial isolates.

The in vitro activity of difloxacin against canine bacterial isolates from clinical cases was studied in the United States and The Netherlands. Minimal inhibitory concentrations (MIC), the postantibiotic effect, the effect of pH on antimicrobial activity, and the bacterial killing rate tests were determined according to standard techniques. The MICs of American and Dutch isolates agreed in general. The MICs of the American gram-negative isolates ranged from 0.06 to 2.0 microg/ml, and the MICs of the Dutch gram-negative isolates ranged from 0.016 to 8.0 microg/ml. A few European strains of Proteus mirabilis and Klebsiella pneumoniae had relatively high MICs. Bordetella bronchiseptica also was less susceptible to difloxacin. The MICs of the American gram-positive cocci ranged from 0.125 to 4.0 microg/ml, and the MICs of Dutch isolates ranged from 0.125 to 2.0 microg/ ml. Difloxacin induced a concentration-dependent postantibiotic effect that lasted 0.2-3 hours in cultures with Escherichia coli, Staphylococcus intermedius, Streptococcus canis, Proteus spp., and Klebsiella pneumoniae. There was no postantibiotic effect observed against canine Pseudomonas aeruginosa. Decreasing the pH of the medium increased the MIC of Proteus mirabilis for difloxacin. The MICs of Escherichia coli and Klebsiella pneumoniae were lowest at neutral pH and were slightly increased in acid or alkaline media. At a neutral pH, most tested bacterial species were killed at a difloxacin concentration of 4 times the MIC. Similar results were obtained when these same bacteria were tested against enrofloxacin. A Klebsiella pneumoniae strain in an acidic environment was readily killed at difloxacin or enrofloxacin MIC, but at neutral pH the drug concentration had to be raised to 4 times the MIC for a bactericidal effect. After 24 hours of incubation at pH 7.1, difloxacin and enrofloxacin had similar bactericidal activity for all bacteria tested except Staphylococcus intermedius. Against S. intermedius, difloxacin was more bactericidal than enrofloxacin.

Animals↗

PubMed1991

Bacterial isolates and drug susceptibility tests at Kaffa Regional Public Health Laboratory, south west Ethiopia.

A two year period bacteriological data was analysed and the frequent bacterial isolates from different clinical specimens included: S. aureus, 25% E. coli, 15%; Proteus spp 14%; Citrobacter-Enterobacter group, 10% coagulase negative Staphylococcus species, 9%; and other miscellaneous bacteria each less than 9%. The majority of the bacterial isolates were resistant to commonly available antimicrobial agents like tetracycline, ampicillin, and chloramphenicol.

Bacteria↗

PubMed1994

Susceptibility patterns of clinical bacterial isolates in nineteen selected hospitals in Thailand.

Susceptibility patterns of 3,115 clinical isolates obtained from blood, urine, sputum and pus in 19 hospitals located in each part of Thailand, were studied using ampicillin, ampicillin plus sulbactam, piperacillin, gentamicin, amikacin, cefazolin, cefuroxime, cefotaxime, ceftazidime, ofloxacin and imipenem. E.coli, S.aureus, P. aeruginosa, Klebsiella spp., Acinetobacter spp., Proteus spp. and Salmonella spp., were the seven most common isolates and accounted for 28.3, 15.3, 14.6, 14.5, 5.2, 3.3 and 3.3 per cent of total isolates respectively. Susceptibility percentages of common bacterial isolates from blood to third-generation cephalosporins, amikacin, ofloxacin and imipenem were satisfactory and higher than those of clinical isolates from other specimens. As expected, nosocomial strains were more resistant than community-acquired strains. Isolates from government hospitals were more resistant to gentamicin and amikacin but more susceptible to ampicillin compared with those from private hospitals. Susceptibility to imipenem among isolates from private hospitals was less but did not reach statistical significance.

Anti-Bacterial Agents↗

PubMed1991

Production of trypsin and chymotrypsin inhibitors by oral bacterial isolates.

Using an agar-skim milk gel method, over 300 oral bacterial isolates were tested for their ability to produce trypsin or chymotrypsin inhibitor. Eleven bacterial strains, including seven isolates identified as Bacteroides intermedius, were found to inhibit both proteolytic activities. The inhibitory factors of the 11 bacterial strains could be divided into two categories: i) heat-stable and dialysable, and ii) heat-labile and non-dialysable. The protease inhibitor activity of B. intermedius strains, which belongs to the latter category, was found in a membrane fraction as well as in a membrane-free extract. Furthermore, three strains of B. intermedius showed this inhibitory activity in the culture supernatant. In combination with plasma-derived protease inhibitors, the production of these additional protease inhibitors by oral bacteria could protect the host from tissue degradation.

Adult↗

PubMed2004

Isolated bacterial meningitis as the key syndrome of infective endocarditis.

BACKGROUND: Bacterial meningitis is an unusual first manifestation but a major complication of infective endocarditis. PATIENTS AND METHODS: We present three well documented cases of isolated bacterial meningitis in endocarditis. Against this background we review the literature. RESULTS: All patients presented with bacterial meningitis. Staphylococcus aureus was isolated in blood cultures of all patients, but was found only in the cerebrospinal fluid (CSF) of one patient. The underlying endocarditis was confirmed histologically in all three cases. Two patients recovered completely and one died. CONCLUSION: An extensive search for endocarditis is recommended in every case of an unusual isolate in bacterial meningitis whether it is isolated from blood or CSF.

Aged↗

PubMed1984

Analysis of bacterial isolates from cerebrospinal fluid.

We set out to determine the frequency of occurrence of contamination of cerebrospinal fluid with bacteria, seeking also to identify aids to differentiating contaminants from etiologically significant isolates. From 2,091 specimens, 182 bacterial isolates were obtained from 129 patients. Meningitis was the source of 81 isolates (32 patients); contamination yielded 101 isolates (97 patients). The cell counts and protein and glucose concentrations in the cerebrospinal fluid were significantly more often abnormal in specimens from patients with meningitis. Haemophilus influenzae and enteric gram-negative bacilli were usually cause for meningitis, whereas Staphylococcus epidermidis was the most common contaminant. In view of the reported high rate of procedural error in carrying out lumbar puncture, a program aimed at teaching proper technique is recommended to decrease the frequency of false-positive cultures of cerebrospinal fluid.

Bacteria↗

PubMed1981

Antigonococcal and antibacterial spectra of some bacterial isolates of the urogenital flora.

The antigonococcal and antibacterial spectra of bacterial isolates of the urogenital flora selected for their in vitro interference of Neisseria gonorrhoeae growth were determined on solid medium. A broad antigonococcal spectrum was found for all the selected isolates when they were tested against gonococcal virulent (T1) strains, penicillinase producing strains and strains belonging to the auxotypes NR, Thi-, Pro- Hyx-, Pro- Meth- Thp-, Arg- Meth- and Arg- Hyx- Ura-. Except for the group D streptococci, all the selected isolates particularly the coagulase negative staphylococci showed a narrow interference spectrum towards aerobic and anaerobic bacterial representatives of the normal urogenital flora. The selected isolates inhibited also the growth of N. meningitidis and N. catarrhalis meaning that they produce antineisserial rather than antigonococcal activities. The crude preparations isolated from cultures of Micrococcus sp. No. 2 and 42, and Acinetobacter sp. No. 13 on solid medium showed similar antigonococcal and antibacterial spectra as those observed with the basal spot/lawn method. These inhibitory activities were characterized for stability to extreme of temperature and pH values, and for susceptibility to different enzyme treatments. Based on ultrafiltration, differences in molecular size were observed between the inhibitors. These substances appear different from the previously reported gonococcal inhibitors of bacterial origin.

Aerobiosis↗

PubMed1985

Nitrogen utilization in bacterial isolates from the equine cecum.

A total of 114 bacterial isolates were obtained from the cecal contents of two mature cecally fistulated horses on a habitat-simulating medium containing 40% energy-depleted cecal fluid. Of these isolates, 108 were maintained in pure cultures and were tentatively grouped on the basis of cell morphology and physiological characteristics. Gram-negative rods (50.9%), gram-positive rods (22.8%), and gram-positive cocci (21.9%) represented the largest groups isolated from these animals. Fifty isolates were tested for their ability to grow in media containing urea, ammonia, peptones, or amino acids as sole nitrogen sources. None of the isolates had a unique requirement for urea or ammonia since nitrogen derived from peptones, amino acids, or both supported growth as well as did ammonia or urea in a low nitrogen medium. Of the cecal isolates, 18% were able to use urea for growth, and 20.5% were able to grow with ammonia as the sole nitrogen source. All organisms grew in the experimental media containing peptones as the sole nitrogen source. Urease activity was detected in only 2 of 114 isolates tested. The inability of isolates to use urea or ammonia as nitrogen sources may have been a reflection of growth conditions in the habitat-stimulating medium used for isolation, but it could also suggest that many cecal bacteria require nitrogen sources other then ammonia or urea for growth.

Animals↗

PubMed2001

Biodegradation of tert-butyl alcohol and related xenobiotics by a methylotrophic bacterial isolate.

A new aerobic bacterial strain, CIP 1-2052, isolated from an activated sludge sample, was able to use tert-butyl alcohol (TBA), a product of methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE) degradation, as its sole carbon and energy source. Cobalt ions stimulated TBA mineralization. The maximum growth and TBA degradation rates were 0.032 +/- 0.004 h(-1) and 35.8 +/- 8.5 mg TBA x g(-1) (cell dry mass) per h, respectively. The growth yield on TBA was 0.54 +/- 0.02 g x g(-1). Strain CIP 1-2052 exhibited a particular substrate specificity towards alcohols. It degraded tertiary alcohols, TBA and tert-amyl alcohol (TAA), but neither their primary and secondary alcohol homologues, nor ethanol. However, one-carbon compounds, namely methanol and formate, were degraded by strain CIP 1-2052, showing the methylotrophic nature of this isolate. The properties of this new strain suggest that it could be used for bioremediation of contaminated aquifers.

Air Pollutants↗

PubMed1999

Inhibition of atrazine degradation by cyanazine and exogenous nitrogen in bacterial isolate M91-3.

A variety of s-triazine herbicides and nitrogen fertilizers frequently occur as co-contaminants at pesticide manufacturing and distribution facilities. The degradation of atrazine and cyanazine by the bacterial isolate M91-3 was investigated in washed-cell suspensions and crude cellular extracts. Cyanazine competitively inhibited atrazine degradation. The maximum atrazine degradation rate (Vmax) was 41 times higher and the half-saturation constant for the inhibitor (Ki) was 1.3 times higher in the crude cellular extract than in the washed-cell suspension, suggesting that cellular uptake influenced degradation of the s-triazines. Cultures that had received prior exposure to atrazine and simazine exhibited comparable atrazine degradation rates, while cells exposed to cyanazine, propazine, ametryne, cyanuric acid, 2-hydroxyatrazine, biuret, and urea exhibited a lack of atrazine-degradative activity. Growth in the presence of exogenous inorganic nitrogen inhibited subsequent atrazine-degradative activity in washed-cell suspensions, suggesting that regulation of s-triazine and nitrogen metabolism are linked in this bacterial isolate. These findings have significant implications for the environmental fate of s-triazines in agricultural settings since these herbicides are frequently applied to soils receiving N fertilizers. Furthermore, these results suggest that bioremediation of s-triazine-contaminated sites (common at pesticide distribution facilities in the cornbelt) may be inhibited by the presence of N fertilizers that occur as co-contaminants.

Atrazine↗

PubMedDate not supplied

Capillary gas chromatography with chemical ionization negative ion mass spectrometry in the identification of odorous steroids formed in metabolic studies of the sulphates of androsterone, DHA and 5alpha-androst-16-en-3beta-ol with human axillary bacterial isolates.

The products of metabolism of the sulphates (0.5 micromol/l) of androsterone, dehydroepiandrosterone (DHA) and 5alpha-androst-16-en-3beta-ol have been investigated after incubation with 72 h cultures of human axillary bacterial isolates for 3 days at 37 degrees C. The medium used, tryptone soya broth (TSB), contained yeast extract and Tween 80. The isolates used were Coryneform F1 (known previously to metabolize testosterone and to be involved in under-arm odour (UAO) production, i.e. UAO +ve), Coryneform F46 (inactive in both the testosterone metabolism and UAO tests, i.e. UAO -ve) and Staphylococcus hominis/epidermidis (IIR3). Control incubations of TSB alone, TSB plus each of the steroid sulphates and TSB plus each of the bacterial isolates were also set up. After termination of reactions and addition of internal standards, 5alpha-androstan-3beta-ol and 5alpha-androstan-3-one (50 ng each), extracted and purified metabolites were subjected to combined gas chromatography-mass spectrometry with specific ion monitoring. Steroidal ketones were derivatized as their O-pentafluorobenzyl oximes; steroidal alcohols (only androst-16-enols in this study) were derivatized as their tert-butyldimethylsilyl ethers. Analysis was achieved by negative ion chemical ionization mass spectrometry for the pentafluorobenzyl oximes at [M-20]- and electron impact positive ion mass spectrometry for the tert-butyldimethylsilyl ethers at [M-57]+. The incubation broth contained two compounds which had gas chromatographic and mass spectrometric properties identical to those of DHA and 4-androstenedione. It was not possible, therefore, to show unequivocally that DHA sulphate (DHAS) was converted microbially into DHA, although this is implied by the finding of small quantities of testosterone and 5alpha-dihydrotestosterone in incubations with F1. With androsterone S, no free androsterone was recorded and only very small (5 pg or less) amounts of testosterone. Two odorous steroids, androsta-4,16-dien-3-one and 5alpha-androst-2-en-17-one (Steroid I) were formed (mean quantities 40 and 45 pg, respectively). The sulphate of 5alpha-androst-16-en-3beta-ol was metabolized with F1 into large quantities of the odorous steroids, 5alpha-androst-16-en-3-one and Steroid I. In addition, much smaller quantities of androsta-4,16-dien-3-one were formed. In contrast, incubations of DHAS with F46 resulted in no metabolites except, possibly, DHA, but the sulphate moiety of androsterone S was also cleaved to yield the free steroid together with large amounts of Steroid I. In incubations of DHAS and androsterone S with F1, no 16-unsaturated steroids were formed, although 5alpha-androst-16-en-3beta-yl S was de-sulphated and the free steroid further metabolized. No evidence was obtained for androst-16-ene metabolism in incubations with F46. In incubations with S. hominis/epidermidis (IIR3), androsterone S was converted into androsterone and, in high yield, to Steroid I plus some 5alpha-androst-16-en-3-one. Both DHAS and androsterone S were converted into androst-16-enols. Sulphatase activity was also manifested when 5alpha-androst-16-en-3beta-yl S was utilized as substrate with IIR3, large quantities of Steroid I and 5alpha-androst-16-en-3-one being formed, together with further metabolism of androst-16-enes. In view of the fact that both DHAS and androsterone S occur in apocrine sweat, the metabolism of these endogenous substrates by human axillary bacteria to several odorous steroids may have important implications in the context of human odour formation.

Actinomycetales↗

PubMed1995

Prevalence and antibiotic sensitivity of Danish versus other European bacterial isolates from intensive care and hematology/oncology units.

The prevalence and antibiotic sensitivity patterns of bacteria collected consecutively from medical and surgical intensive care units (ICUs) and from hematology/oncology units in nine hospitals in Denmark were determined and compared to data collected simultaneously in 12 other European countries. Bacterial isolates from 794 Danish patients were tested and compared to 8,625 isolates from European patients. The minimal inhibitory concentrations of eight different antibiotics were determined using a microdilution plate. Similar to findings in European countries, the most common source of bacterial isolates in Danish units was the respiratory tract (49%), followed by blood (18%), urinary tract (14%) and surgical wounds (10%). Staphylococcus aureus was the most prevalent respiratory organism in Danish units, whereas Enterobacteriaceae and Pseudomonas aeruginosa dominated in other countries. In blood, Escherichia coli was most prevalent in Denmark while coagulase-negative staphylococci were predominant in other countries. Urinary tract isolates were dominated by Escherichia coli in both Denmark and the other countries, but Enterococcus faecalis and Pseudomonas aeruginosa were more frequently isolated in the other countries. Staphylococcus aureus was the most frequent wound isolate in Denmark, while Enterobacteriaceae other than Escherichia coli dominated in other European countries. Thus, in Denmark Escherichia coli and Staphylococcus aureus, followed by Pseudomonas aeruginosa and Klebsiella spp. (from ICUs) or Enterococcus spp. and Klebsiella spp. (from hematology/oncology units), are the most prominent pathogens in these units today. Indicator organisms of antibiotic consumption (Pseudomonas aeruginosa and methicillin-resistant coagulase-negative staphylococci and Staphylococcus aureus) were more frequent in other European countries than Denmark. In general the Danish isolates were more sensitive to antibiotics than the European isolates.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗

PubMed1995

In vitro efficacy of cefquinome (INN) and other anti-infective drugs against bovine bacterial isolates from Belgium, France, Germany, The Netherlands, and the United Kingdom.

The in vitro antibacterial activity of cefquinome (INN), an aminothiazolyl-cephalosporin of the fourth generation of cephalosporins, was investigated by determining the minimal inhibitory concentration (MIC, microgram/ml) for 714 bacterial isolates of bovine origin and comparing it with those of amoxicillin, amoxicillin and clavulanic acid, ceftiofur, cephapirin, enrofloxacin, gentamicin, kanamycin and oxytetracycline. Drug resistance was determined by using break-points, which consider the dosage regimen and pharmacokinetics of the veterinary antimicrobials investigated. Cefquinome demonstrated a very high in vitro activity against bacterial isolates of Pasteurella spp., Escherichia coli and Salmonella spp. Overall, the level of resistance against the different anti-infectives tested was lowest for cefquinome. For the remaining substances examined, in vitro activity and the level of resistance showed considerable differences. The chemical and pharmaceutical features of cefquinome are discussed.

Animals↗

PubMed1986

Etiologic significance of bacterial isolates from rams with palpable epididymitis.

Identified and partly identified bacterial isolates were obtained from 48 rams of various breeds that had unilateral or bilateral epididymitis. Most of the animals were approximately 1 year of age; a few were older. Brucella ovis, Actinobacillus spp, Corynebacterium spp, Haemophilus spp, Acinetobacter spp, Escherichia coli, Moraxella spp, Staphylococcus spp, Pasteurella spp, Streptococcus spp, and Chlamydia psittaci were isolated. A vaccine strain of B ovis, isolated species of bacteria, and mixtures of isolates of tissue homogenates containing all isolates except B ovis and C psittaci were inoculated via the mucous membranes of the eyes, nares, and prepuce. Palpable epididymitis was not produced by the inoculations. The vaccine strain of B ovis induced complement-fixation reaction in 11 of 20 rams.

Acinetobacter↗