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PubMed1991

Purification and properties of an organophosphorus acid anhydrase from a halophilic bacterial isolate.

A moderately halophilic bacterial isolate has been found to possess high levels of enzymatic activity against several highly toxic organophosphorus compounds. The predominant enzyme, designated organophosphorus acid anhydrase 2, has been purified 1,000-fold to homogeneity and characterized. The enzyme is a single polypeptide with a molecular weight of 60,000. With diisopropylfluorophosphate as a substrate, the enzyme has optimum activity at pH 8.5 and 50 degrees C, and it is stimulated by manganese and cobalt.

Antibodies, Monoclonal↗

PubMed1987

[Clinical observation of bacterial isolates from urine specimens of outpatients].

Changes of bacterial isolates from urine specimens of outpatients with urinary tract infections (UTI) from 1977 through 1984 were studied. Organisms which were isolated from patients with bacteriuria of over 10(3) bacteria per ml of urine regardless of grade of pyuria were studied. The incidence of UTI, especially that of acute cystitis was decreased during the recent 8 years. E. coli was the most predominant isolate in acute UTI with an isolation frequency of over 70% every year, followed by S. epidermidis nearly every year. Citrobacter spp., Klebsiella spp., P. mirabilis and S. aureus were also isolated steadily every year. Bacterial isolates in acute UTI were generally composed of these six species of bacteria. Although many kinds of bacteria were isolated in chronic UTI, E. coli was the most frequent species with an isolation frequency of 17-37%, followed by E. faecalis except in 1981 and 1982. The tendency of gram-negative rods to increase in acute and chronic UTI was observed except in 1981 and 1982. A slight decrease in sensitivity of E. coli and P. mirabilis against ampicillin (ABPC) and sulbenicillin (SBPC) was observed in acute UTI. In chronic UTI, the tendency of the sensitivity of E. coli against ABPC, SBPC and nalidixic acid to recover and the tendency of the sensitivity of P. aeruginosa against dibekacin to decrease were observed. E. faecalis was estimated to be sensitive to gentamicin, cefazolin, minocycline and fosfomycin. However, unlike those species mentioned above, many strains of E. faecalis showed a positive disc sensitivity to these drugs.

Acute Disease↗

PubMed2005

[Analysis of drug resistance spectrum and its mechanism in 1017 clinical bacterial isolates].

OBJECTIVE: To investigate the drug susceptibility of the clinical bacterial isolates to provide evidence for more adequate use of antibiotics. METHODS: Altogether 1017 clinical bacterial isolates were identified by BD Phoenix and tested for resistance against antimicrobial agents by K-B method. WHONET5 was applied for the analysis. RESULTS: The most frequent bacteria detected included P. aeruginosa (19.37%), coagulase-negative Staphylococci (CNS, 17.70%), E. coli (13.27%), S. aureu (SA, 12.09%), E. faecalis (11.8%), and K. pneumoniae (7.57%). In gram-negative isolates, the susceptibility rate of imipenem was 81.5%, and that of ceftazidime was above 70%. The incidences of E.coli and K. pneumoniae isolates producing extended spectrum beta-lactamase (ESBLs) were 34.8% and 45.5% respectively. In gram-positive isolates, the susceptibility rates of vancomycin and Teicoplanin were 98.8% and 100.0% respectively, and those of furazolidone, imipenem, amikacin, piperacillin/ tazobactam were above 70%. The oxacillin resistant rates of CNS and SA were 78.2% and 46.8%. CONCLUSION: The 1017 clinical bacterial isolates are characterized by high ratio of ESBL production and oxacillin resistance, suggesting the importance of adequate use of antimicrobial agents and effective control measures for reducing the drug resistance and preventing the spread of multi drug- resistant bacteria.

Anti-Bacterial Agents↗

PubMed2000

Identification and characterization of humic substances-degrading bacterial isolates from an estuarine environment.

Bacterial isolates were obtained from enrichment cultures containing humic substances extracted from estuarine water using an XAD-8 resin. Eighteen isolates were chosen for phylogenetic and physiological characterization based on numerical importance in serial dilutions of the enrichment culture and unique colony morphology. Partial sequences of the 16S rRNA genes indicated that six of the isolates were associated with the alpha subclass of Proteobacteria, three with the gamma-Proteobacteria, and nine with the Gram-positive bacteria. Ten isolates degraded at least one (and up to six) selected aromatic single-ring compounds. Six isolates showed ability to degrade [(14)C]humic substances derived from the dominant salt marsh grass in the estuary from which they were isolated (Spartina alterniflora), mineralizing 0.4-1.1% of the humic substances over 4 weeks. A mixture of all 18 isolates did not degrade humic substances significantly faster than any of the individual strains, however, and no isolate degraded humic substances to the same extent as the natural marine bacterial community (3.0%). Similar studies with a radiolabeled synthetic lignin ([beta-(14)C]dehydropolymerisate) showed measurable levels of degradation by all 18 bacteria (3.0-8.8% in 4 weeks), but mineralization levels were again lower than that observed for the natural marine bacterial community (28.2%). Metabolic capabilities of the 18 isolates were highly variable and generally did not map to phylogenetic affiliation.

Journal Article↗

PubMed2005

Bacterial isolates in severely malnourished children at Kenyatta National Hospital, Nairobi.

OBJECTIVES: To identify bacterial isolates and determine antibiotic sensitivity pattern in children with severe Protein Energy Malnutrition (PEM) presenting at the Paediatric Filter Clinic (PFC) of Kenyatta National Hospital (KNH). DESIGN: Hospital based cross-sectional survey. SETTING: Paediatric Filter Clinic of Kenyatta National Hospital (KNH), a tertiary level teaching institution for the University of Nairobi, Kenya. SUBJECTS: Children between two and sixty months presenting at the hospital outpatient filter clinic with severe malnutrition. RESULTS: Ninety-one children, forty six female and forty five males, were recruited for the study. Of these, sixty had Marasmus, twenty Kwashiorkor and eleven Marasmic-Kwashiorkor. HIV serology was positive in 43% of study subjects. There were 30 bacterial isolates from 26 subjects. Ten bacterial isolates were gram positive and twenty gram negative. Isolation rates did not vary by HIV serological status. Twenty one out of the 30 isolates were from blood culture. About 1/3 of the gram positive isolates were coagulase negative staphylococci, largely resistant to commonly used antibiotics such as Erythromycin, Ampicillin, Cotrimoxazole, Chloramphenicol and even Oxacillin. More than half demonstrated resistance to commonly used oral antibiotics while 80% of all gram positive and negative isolates were sensitive to Ciprofloxacin. Aminoglycosides, Gentamicin and Amikacin, and third generation Cephalosporins, Ceftriaxone and Ceftazidime, were found to be effective against most gram-negative isolates. CONCLUSION: Nearly a third (28.9%) of children admitted with severe malnutrition at KNH have concomitant severe bacterial infections; primarily manifesting as bacteraemia. Gram-negative agents are responsible for most severe bacterial infections in children admitted at the KNH, regardless of their HIV serological status. Whenever possible, blood culture should be included in the initial septic screening of severely malnourished children at KNH. In the absence of culture and sensitivity information, ciprofloxacin should be considered among the first line options in the empirical treatment of severe bacterial infections among these children. Clinical trials to further evaluate in-vivo effectiveness of various single or combination antibiotics are recommended.

Age Distribution↗

PubMed2003

Identification and antibiotic susceptibility of bacterial isolates from probiotic products.

In the present study, a total of 55 European probiotic products were evaluated with regard to the identity and the antibiotic resistance of the bacterial isolates recovered from these products. Bacterial isolation from 30 dried food supplements and 25 dairy products, yielded a total of 268 bacterial isolates selected from several selective media. Counts of food supplements showed bacterial recovery in 19 (63%) of the dried food supplements ranging from 10(3) to 10(6) CFU/g, whereas all dairy products yielded growth in the range of 10(5)-10(9) CFU/ml. After identification of the isolates using whole-cell protein profiling, mislabeling was noted in 47% of the food supplements and 40% of the dairy products. In six food supplements, Enterococcus faecium was isolated whereas only two of those products claim this species on their label. Using the disc diffusion method, antibiotic resistance among 187 isolates was detected against kanamycin (79% of the isolates), vancomycin (65%), tetracycline (26%), penicillinG (23%), erythromycin (16%) and chloramphenicol (11%). Overall, 68.4% of the isolates showed resistance against multiple antibiotics including intrinsic resistances. Initially, 38% of the isolated enterococci was classified as vancomycin resistant using the disc diffusion method, whereas additional broth dilution and PCR assays clearly showed that all E. faecium isolates were in fact vancomycin susceptible.

Anti-Bacterial Agents↗

PubMed1983

A comparison of manganese oxidation by growing and resting cells of a freshwater bacterial isolate, strain FMn 1.

A bacterial isolate, strain FMn 1, from reservoir sediment oxidized MN2+ when tested in growing culture and resting-cell suspension. The oxidation was biologically mediated and not the result of autoxidation because at a MnSO4 . H2O concentration of 0.05%, the pH remained below 7.5 for the duration of the experiments. The production of manganese oxide was qualitatively and quantitatively demonstrated. The manganese-oxidizing activity of this organism was found to be inducible.

Bacteria↗

PubMedDate not supplied

Frequency of occurrence and antimicrobial susceptibility of bacterial isolates from the intestinal and female genital tracts.

In the selection of empiric therapy for infections of the female genital tract and intraabdominal infections in humans, the requisite information includes (1) the frequency of isolation of bacterial species dominant in the normal gastrointestinal and female genital tracts and in intraabdominal and female genital tract infections and (2) the in vitro susceptibilities of the dominant species to drugs that may be used against them (e.g., penicillin G, cefoperazone, cefoxitin, chloramphenicol, clindamycin, and metronidazole). The predominant bacteria in fecal contents are not necessarily those most frequently found in infections. Intraabdominal and perirectal infections are usually polymicrobial, resulting from mixtures of facultative species (coliforms and streptococci) and anaerobes. The predominant bacteria of the normal vagina and cervix are lactobacilli, facultative streptococci, Peptococcus species, and Peptostreptococcus species. Most infections of the female genital tract are due to mixtures of facultative enteric bacilli, streptococci, and anaerobes (Peptococcus and Peptostreptococcus species, Bacteroides fragilis, Bacteroides disiens, Bacteroides melaninogenicus, Bacteroides bivius, and Bacteroides asaccharolyticus). Of the antibiotics tested, clindamycin appears the most active against many of the groups of bacteria isolated.

Abdomen↗

PubMed1995

Antibiogram of bacterial isolates from cases of otitis media and lower respiratory tract infections.

A total of one hundred and two cases of otitis media were screened for the isolation of bacterial flora of ears. Out of this, Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae accounting for 41.2%, 25.5% and 13.3% respectively were isolated. A further two hundred and four sputum samples from cases of lower respiratory tract infections were screened. Moraxella catarrhalis, S. aureus, S. pneumoniae and H. influenzae constituting 20.9%, 37%, 30% and 21% were isolated in that order. Thirty-one point seven percent of the Moraxella catarrhalis isolates were beta-lactamase positive. Beta-lactamase M. catarrhalis were resistant to penicillin and ampicillin while the non-beta-lactamase producers were sensitive to these antimicrobial agents. However, both beta-lactamase producers and non-producers were resistant to trimethoprim but sensitive to erythromycin, tetracycline and amoxycillin. Staphylococcus aureus, S. pneumoniae and H. influenzae was also sensitive to penicillin while S. pneumoniae was also sensitive to erythromycin and H. influenzae to chloramphenicol.

Adolescent↗

PubMed1999

Trovafloxacin susceptibility of aerobic clinical bacterial isolates from Sweden.

Trovafloxacin susceptibility was studied in aerobic clinical isolates of bacterial pathogens from 5 microbiology laboratories in Sweden. Trovafloxacin and ciprofloxacin minimum inhibitory concentration (MIC) determinations were performed on 474 clinical isolates. Disk diffusion tests using trovafloxacin and ciprofloxacin 10 microg disks were performed on a total of 7142 clinical isolates (trovafloxacin). Susceptibility interpretations for trovafloxacin and ciprofloxacin were determined from MIC values and disk diffusion tests using species-related MIC-limits and zone diameter breakpoints. Eight of 12 gram-positive species groups were fully susceptible to trovafloxacin as judged by MIC tests. Trovafloxacin gave MIC50 values of 0.032 mg/l for S. aureus, 1.0 mg/l for MRSA, 0.064 mg/l for coagulase negative staphylococci, 1.0 mg/l for MRSE, 0.064 mg/l for S. saprophyticus, 0.125 mg/l for group A and group B streptococci, 0.064 mg/l for group C and G streptococci and S. pneumoniae, 0.25 mg/l for E. faecalis, and 16.0 mg/l for E. faecium. These MIC values were 4-16-fold lower than those of ciprofloxacin. Both MIC and disk tests showed similar levels of susceptibility among gram-negative isolates for trovafloxacin and ciprofloxacin. For most gram-negative species the trovafloxacin MIC50 values were similar to or slightly higher than those for ciprofloxacin. Trovafloxacin MIC values were much lower for Acinetobacter strains, but higher for P. mirabilis compared with ciprofloxacin. The favourable susceptibility levels of Swedish aerobic pathogens to trovafloxacin emphasize the potential of this drug for the treatment of serious infections.

Anti-Infective Agents↗

PubMedDate not supplied

In vitro antibiotic sensitivity pattern of common bacterial isolates from cases of acute bacterial meningitis with special reference to ceftriaxone.

Ceftriaxone (RO 13-9904) has only recently been introduced in Benghazi and many parts of the word. We determined its in-vitro antibacterial activity against the primary aetiological agents of childhood meningitis in Benghazi, that included eighteen (23.3%) strains of H. influenzae, 17 (22.1%) of Str. pneumoniae and 1 (1.3%) of N. meningitidis isolated from 77 cases of acute purulent meningitis above the age of neonatal period. All strains of H. influenzae. Str. pneumoniae and N. meningitidis were sensitive to ceftriaxone and showed wide zones of inhibition by the disc diffusion technique of Kirby-Bauer. Ampicillin and chloramphenicol resistance was observed for H. influenzae (23% and 11% respectively), and Str. pneumoniae (12% and 0% respectively), in addition, 18% of strains of Str. pneumoniae showed resistance to penicillin. The broad spectrum activity of ceftriaxone has been confirmed for our locality and this finding, together with its exceptionally long half-life, excellent penetration into the C.S.F. and ease of administration (single daily dose) warrants it as the drug of choice in empherical treatment of cases of acute bacterial meningitis in children in Benghazi and in cases where resistance to ampicillin and chloramphenicol are found on subsequent testing.

Acute Disease↗

PubMed1981

Transformation of bile acids by mixed microbial cultures from human feces and bile acid transforming activities of isolated bacterial strains.

Microbiol transformation of cholic acid and chenodeoxycholic acid by anaerobic mixed cultures of human fecal microorganisms was investigated, and the results were examined in relation to the bile acid transforming activities of 75 bacterial strains isolated from the same fecal cultures. The reactions involved in the mixed cultures were dehydrogenation and dehydroxylation of the 7 alpha-hydroxy group in both primary bile acids and epimerization of the 3 alpha-hydroxy group in all metabolic bile acids. Extensive epimerization of the 7 alpha-hydroxy group of chenodeoxycholic acid yielding ursodeoxycholic acid was also demonstrated by certain fecal samples. 7 alpha-Dehydrogenase activity was widespread among the fecal isolates (88% of 16 facultative anaerobes and 51% of 59 obligate anaerobes), and 7 alpha-dehydroxylase activity was revealed in one of the isolates, and unidentified gram-positive nonsporeforming anaerobic bacterium. 3 alpha-Epimerization was effected by seven strains assigned to Eubacterium lentum, which were also active for 3 alpha- and 7 alpha-dehydrogenations. No microorganism accounting for 7 alpha-epimerization was recovered among the isolates. Splitting of conjugated bile acid was demonstrated by the majority of obligate anaerobes but the activity was rare among facultative anaerobes.

Bacteria↗

PubMed1983

The turbidimetric stability of common clinical bacterial isolates in water.

Ninety common clinical bacterial isolates were suspended in sterile deionized, tap and lake water to a turbidity of 100 Klett-Summerson Colorimeter Units. The suspensions were then measured for turbidity at seven and 14 days of storage at 25 degrees C. Turbidities for Proteus mirabilis, Klebsiella pneumoniae and Escherichia coli were stable for 14 days, however those of Serratia marcescens, Pseudomonas aeruginosa, Staphylococcus aureus and S. epidermidis were unstable as evidenced by a decreased turbidity. Staphylococci were much less stable in deionized water than tap or lake water. Overall, the turbidity of most isolates was most stable in lake followed by tap and deionized water, respectively.

Bacterial Physiological Phenomena↗

PubMed1977

Influence of hydrostatic pressure on the effects of the heavy metal cations of manganese, copper, cobalt, and nickel on the growth of three deep-sea bacterial isolates.

Increases hydrostatic pressure varied the 72-h growth yield of three bacterial isolates from the deep sea in the presence of heavy metal cations of Mn, Cu, Co, and Ni, depending on the bacterial isolate, the metal cation and its concentration, and the level of hydrostatic pressure. Above atmospheric, hydrostatic pressure was found to have one of the following four effects on the response of culture growth to a heavy metal cation. (i) It could be without effect; (ii) it could enhance inhibition by a metal cation; (iii) it could increase the 72-h growth yield by a metal cation; or (iv) it could protect against a growth inhibitory effect noted at a lower pressure. Possible reasons for these varied responses are discussed.

Bacteria↗

PubMed2006

Biosorption of chromium and nickel by heavy metal resistant fungal and bacterial isolates.

Microorganisms play a significant role in bioremediation of heavy metal contaminated soil and wastewater. In this study, heavy metal resistant fungi and bacteria were isolated from the soil samples of an electroplating industry, and the bioaccumulations of Cr(VI) and Ni(II) by these isolates were characterized to evaluate their applicability for heavy metal removal from industrial wastewaters. The optimum pH and temperature conditions for both the growth and heavy metal removal were determined for each isolate. The optimal pH for fungal isolates was lower (5-5.2) than that for bacterial isolates (7). The observed effect(s) of pH was attributable mainly to organism-specific physiology because in all the tested cases the cellular growth positively correlated with heavy metal removal. Batch and tolerance experiments provided information for solid retention time (SRT) design and the lethal tolerance limits for the isolated microorganisms. Experimental results indicated that expanded SRTs (stationary phase) can be recommended while using the fungal and bacterial Cr-resistant isolates for removing chromium. In the case of Ni-resistant bacterial isolate, a non-expanded SRT was recommended for designing continuous-flow completely stirred (CFCS) bioreactor so that a mid-log phase of cellular growth can be kept during the bioaccumulation process. The tolerance data with a high range of heavy metal concentrations revealed the Cr-resistant isolates, especially the fungal one, could tolerate chromium toxicity at up to 10,000 mg L(-1) chromium. Result indicates the applicability of the isolated Micrococcus sp. and Aspergillus sp. for the removal of chromium and nickel from industrial wastewater.

Adsorption↗

PubMed1990

[Susceptibilities of clinical bacterial isolates to antimicrobial agents. A study mainly focused on imipenem. Research Group for Testing Imipenem Susceptibility on Clinical Isolates].

We investigated susceptibilities of clinical bacterial isolates to imipenem (IPM) and other antimicrobial agents at 459 hospital laboratories throughout Japan from September to December of 1988. In this study, identification and susceptibility testing were performed at each hospital laboratory and the tests were carried out according to the 1-dilution or 3-dilution disc technique in which susceptibilities are classified into 4 grades: , ++, + and -. IPM had significantly high activity against Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Neisseria gonorrhoeae, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Salmonella spp., Citrobacter freundii, Proteus mirabilis, Providencia rettgeri, Acinetobacter calcoaceticus, Moraxella catarrhalis, Alcaligenes spp., Peptococcus spp./Peptostreptococcus spp., Bacteroides fragilis and Bacteroides spp. and should slightly lower activities on coagulase-negative staphylococci (CNS), Enterococcus faecalis, Haemophilus influenzae, Serratia marcescens, Proteus vulgaris, Providencia stuartii and Pseudomonas aeruginosa than on the above mentioned bacteria. In a comparative study on activities of IPM against bacteria from different clinical sources, no remarkable differences were found due to different sources among S. pneumoniae, E. faecalis, H. influenzae, E. coli, K. pneumoniae, E. cloacae, C. freundii, P. mirabilis or A. calcoaceticus, whereas slight differences were found among Staphylococcus aureus, CNS, S. marcescens and P. aeruginosa.

Anti-Bacterial Agents↗

PubMed1978

Growth characteristics of three bacterial isolates from an arctic soil.

Three bacterial isolates, a Pseudomonas sp., a Bacillus sp., and an Arthrobacter sp., commonly isolated from a hummocky sedge-moss meadow at Devon Island, N.W.T., Canada, were selected for further taxonomic characterization and for a study of the effects of temperature and limiting carbon source on growth. Pseudomonas M216 resembled P. putida and Bacillus M153, B. carotarum. Arthrobacter M51 had growth-factor requirements which were more complex than those of any named species of that genus. The temperature ranges of growth indicated that Pseudomonas M216 and Arthrobacter M51 were psychrotrophic while Bacillus M153 was mesophilic. Growth in batch culture at limiting glucose concentrations enabled the calculation of Ks and Y values for each isolate. These were similar to those obtained for other organisms and Pseudomonas M216 and Bacillus M153 showed a high affinity for glucose. The nutritional versatility of Arthrobacter M51 and its ability to grow at low temperatures and the high growth rates and affinity of Pseudomonas M216 for low substrate concentrations may account for their competitive abilities in the natural environment, while the inability of Bacillus M153 to grow at low temperatures may limit its activity in tundra soils.

Arctic Regions↗

PubMed1991

[Susceptibilities of clinical bacterial isolates to antimicrobial agents, 1989. A study mainly focused on imipenem. The Research Group for Testing Imipenem Susceptibilities of Clinical Isolates].

We investigated susceptibilities of clinical bacterial isolates to imipenem (IPM) and other antimicrobial agents at hospital laboratories throughout Japan from September to December of 1989. The susceptibility testing was carried out according to the 1-dilution or 3-dilution disc technique in which susceptibilities are classified into 4 grades: (+++), (++), (+) and (-). IPM showed markedly high in vitro activities against Streptococcus pneumoniae, Neisseria gonorrhoeae, Moraxella catarrhalis, Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Citrobacter freundii, Acinetobacter calcoaceticus, Bacteroides fragilis and had rather strong activities against Enterococcus faecalis, Haemophilus influenzae, Serratia marcescens, Proteus mirabilis, Morganella morganii, Pseudomonas aeruginosa and Achromobacter xylosoxidans, but was less active to Staphylococcus aureus, coagulase-negative staphylococci and Xanthomonas maltophilia. IPM has been found to have activities superior to those of other antibiotics tested against E. faecalis, E. cloacae, C. freundii, S. marcescens, P. aeruginosa and B. fragilis. No antibiotics tested showed good activities against MRSA except minocycline.

Bacteria↗