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PubMed2000

Spectrum of aetiological agents of postoperative endophthalmitis and antibiotic susceptibility of bacterial isolates.

PURPOSE: To determine the spectrum of infectious agents of postoperative endophthalmitis, the relationship with the time of onset of symptoms after surgery and the antibiotic susceptibilities of the aerobic bacterial isolates. METHODS: A retrospective review of microbiological records from January 1995 to December 1998 yielded 173 isolates from intraocular specimen of 170 patients with culture-proven postoperative endophthalmitis. Antibiotic susceptibility of these isolates was determined for various ocular antibiotics using the Kirby-Bauer disk-diffusion test. Based on the time of onset of illness, clinical presentation was classified into acute, delayed and chronic. RESULTS: Among 170 cases, 71 (41.7%) were attributable to gram-negative, 64 (37.6%) to gram-positive bacteria, and 37 (21.8%) to fungi. Gram-negative bacteria included P. aeruginosa (29;17.1%), other Pseudomonas spp (15;8.8%), non-fermenters (18;10.6%) and others (10;5.8%). Among these, 40 of 72 (55.5%) were sensitive to gentamicin, 47 of 72 (65.2%) to cefotaxime, 47 of 69 (68.1%) to amikacin, 52 of 71 (73.2%) to ciprofloxacin, and 25 of 40 (62.5%) to ceftazidime. The gram-positive bacteria included S. epidermidis (22;12.9%), S. aureus (13;7.6%), P. acnes (10;5.9%), Enterococcus spp (4;2.3%), Streptococcus spp (7;4.1%) and others (8;4.8%). Among these, 41 of 53 (77.3%) were sensitive to gentamicin, 47 of 53 (88.6%) to cefotaxime, 46 of 52 (88.4%) to ciprofloxacin, 38 of 41 (92.6%) to cefazolin and 27 of 37 (72.9%) to ceftazidime. All gram-positive bacteria were sensitive to vancomycin. CONCLUSION: In this large series of postoperative endophthalmitis, gram-negative bacilli followed by fungi accounted for the largest number of cases. A high degree of resistance of gram-negative bacilli to gentamicin, cefotaxime, amikacin and ceftazidime was recorded.

Anti-Bacterial Agents↗

PubMed1991

Multicenter evaluation of the in vitro activities of three new quinolones, sparfloxacin, CI-960, and PD 131,628, compared with the activity of ciprofloxacin against 5,252 clinical bacterial isolates.

The in vitro activities of three new quinolones (sparfloxacin, CI-960, and PD 131,628) were compared with that of ciprofloxacin against 5,252 routine clinical aerobic and facultatively anaerobic bacterial isolates. Overall, CI-960 was the most active drug in vitro (MIC for 90% of the strains tested, 0.13 micrograms/ml); ciprofloxacin and sparfloxacin were the least active (MIC for 90% of the strains tested, 1.0 micrograms/ml). All three new quinolones, but particularly CI-960 and PD 131,628, exhibited significantly greater activity than ciprofloxacin against enterococci and staphylococci.

Anti-Infective Agents↗

PubMed1982

Comparative in vitro activity of norfloxacin (MK-0366) and ten other oral antimicrobial agents against urinary bacterial isolates.

The in vitro activity of a new oral antimicrobial agent, norfloxacin (MK-0366), was compared with those of nalidixic acid, nitrofurantoin, co-trimoxazole, trimethoprim, sulfamethoxazole, cinoxacin, tetracycline, ampicillin, carbenicillin, and cephalexin against 628 urinary bacterial isolates. Norfloxacin was the most active antimicrobial agent tested against the gram-negative bacilli. It was less active than a few of the other antimicrobial agents against enterococci and Staphylococcus aureus.

Anti-Bacterial Agents↗

PubMed1998

Production of cyclomaltononaose (delta-cyclodextrin) by cyclodextrin glycosyltransferases from Bacillus spp. and bacterial isolates.

The conversion of soluble starch to cyclomaltohexaose (alpha-CD), cyclomaltoheptaose (beta-CD), cyclomaltooctaose (gamma-CD) and cyclomaltononaose (delta-CD) by cyclodextrin glycosyltransferases (E.C. 2.4.1.19) from Bacillus spp. and bacterial isolates was studied. The results show that delta-CD was formed by all the enzymes investigated in the range of 5%-11.5% of the total amount of alpha-, beta-, gamma-, and delta-CD produced.

Bacillus↗

PubMed1983

Progressive increase in antibiotic resistance of gram-negative bacterial isolates. Walter Reed Hospital, 1976 to 1980: specific analysis of gentamicin, tobramycin, and amikacin resistance.

During a five-year period at Walter Reed Army Hospital, Washington, DC, the frequency of aminoglycoside resistance among clinical bacterial isolates increased from less than 1% in 1976 to 13% of all isolates in later years. This resistance was seen among frequently isolated species of gram-negative bacilli isolated from patients throughout the hospital and from all anatomical sites, including blood. The incidence of gentamicin and amikacin resistance rose with increased administration of these antibiotics; however, the incidence of tobramycin resistance increased despite its minimal usage. From 1977 to 1978 and from 1979 to 1980, there was a decrease in the conjugal transmissibility of resistance to gentamicin and tobramycin. There was no detectable transmissible amikacin resistance. These findings suggest that high priority must be given to strategies that limit the emergence and dissemination of organisms resistant to these important antibiotics.

Amikacin↗

PubMed1994

A 16-year survey of changes in bacterial isolates associated with chronic suppurative otitis media.

Bacteria were isolated and cultured from the ears of outpatients with chronic suppurative otitis media (OMC) who attended the otologic clinics of Kyushu University Hospital from 1976 to 1991. Bacterial isolates were analyzed retrospectively to determine their incidences and antibiotic sensitivities. Staphylococcus aureus and Pseudomonas aeruginosa were the most commonly isolated organisms. The incidence of S. aureus infections gradually rose over 16 years, while the incidence of Proteus infections gradually declined. The frequency of isolation of glucose non-fermenting gram-negative rod (NF-GNR) species, fungi and anaerobic bacteria gradually increased. The species of bacteria isolated from OMC cases with acute and chronic infections, cholesteatoma and postoperative infections were compared. Over the 16 years, the isolation of S. aureus increased in frequency. The differences in each type of OMC ceased to exist. S. aureus were quite sensitive to most of the antibiotics tested, whereas Ps. aeruginosa and NF-GNR showed poor sensitivity.

Acute Disease↗

PubMed2005

Biofilm formation characteristics of bacterial isolates retrieved from a reverse osmosis membrane.

High-quality water purification systems using reverse osmosis (RO) membrane separation have faced a major challenge related to biofilm formation on the membrane surface, or biofouling. To understand this issue, the biofilm formation characteristics of four bacterial isolates previously retrieved from an RO membrane treating potable water were investigated. Biofilm formation of all four isolates occurred to different extents in microtiter plates and could be related to one or more cell properties (hydrophobicity, surface charge, and motility). For Dermacoccus sp. strain RO12 and Microbacterium sp. strain RO18, bacterial adhesion was facilitated by cell surface hydrophobicity, and for Rhodopseudomonas sp. strain RO3, adhesion was assisted by its low surface charge. Sphingomonas sp. strain RO2 possessed both twitching and swarming motilities, which could be important in mediating surface colonization. Further, strains RO2, RO3, and RO12 did not exhibit swimming motility, suggesting that they could be transported to RO membrane surfaces by other mechanisms such as convective permeate flow. The biofilm formation of RO2 was further tested on different RO membranes made of cellulose acetate, polyamide, and thin film composite in continuous flow cell systems. The resultant RO2 biofilms were independent of membrane surface properties and this was probably related to the ex-opolysaccharides secreted bythe biofilm cells. These results suggested that RO2 could colonize RO membranes effectively and could be a potential fouling organism in RO membranes for freshwater purification.

Bacterial Physiological Phenomena↗

PubMed1994

In vitro activity of FK-037, a novel parenteral cephalosporin, against bacterial isolates from neutropenic cancer patients.

The in vitro activity of FK-037, a novel parenteral cephalosporin, was compared to that of ceftazidime, aztreonam and piperacillin (agents often used in empiric regimens in cancer patients) against recent bacterial isolates from patients with cancer. FK-037 was either equal to or 2 to 16-fold more active than the comparative agents against members of the Enterobacteriaceae. It was also active against Acinetobacter spp., Aeromonas spp., Pseudomonas aeruginosa, and other Pseudomonas spp. Xanthomonas maltophilia and Alcaligenes denitrificans were relatively resistant to all four agents. FK-037 was also 4 to 16-fold more active against most gram-positive organisms (including some methicillin-resistant staphylococci) than was ceftazidime. Enterococcus spp., Listeria monocytogenes and Staphylococcus haemolyticus were relatively resistant to FK-037 and ceftazidime. Overall, FK-037 has a broad antimicrobial spectrum that includes the majority of gram-positive and gram-negative isolates.

Aztreonam↗

PubMed1999

Comparative activities of six different fluoroquinolones against 9,682 clinical bacterial isolates from 20 European university hospitals participating in the European SENTRY surveillance programme. The SENTRY participants group.

The in-vitro activities of gatifloxacin, trovafloxacin, levofloxacin, sparfloxacin, ofloxacin, and ciprofloxacin were tested against 9,682 clinical bacterial isolates from 20 European university hospitals participating in the European SENTRY surveillance programme. Gatifloxacin and trovafloxacin exhibited the highest activities against gram-positive cocci, while levofloxacin, ofloxacin, ciprofloxacin, and gatifloxacin were the most active against Enterobacteriaceae. Ciprofloxacin and levofloxacin showed the highest antimicrobial activities against Pseudomonas spp., while gatifloxacin and trovafloxacin were the most active against Acinetobacter spp. and Stenotrophomonas maltophilia. All Haemophilus spp. and Moraxella catarrhalis isolates were fully susceptible to all quinolones tested. Overall, the new quinolones, showed improved activity against gram-positive cocci and gram-negative non-fermenters while retaining their broad-spectrum activity against gram-negative bacilli.

Anti-Infective Agents↗

PubMed2001

In vitro activities of three nonfluorinated quinolones against representative bacterial isolates.

In vitro susceptibility tests were performed to document the inhibitory activities of three nonfluorinated quinolone (NFQ) compounds (PGE 9262932, PGE 9509924, and PGE 4175997) compared to those of ciprofloxacin, levofloxacin, and trovafloxacin against 3,030 bacterial isolates. The spectra of the NFQ agents included most gram-positive species as well as quinolone-susceptible Enterobacteriaceae. Ciprofloxacin-resistant, methicillin-resistant Staphylococcus aureus strains were inhibited by the NFQ series at < or =1.0 microg/ml. The NFQ compounds were not very active against Pseudomonas aeruginosa and most other nonfermentative gram-negative bacilli. Against other species, the potency of the NFQ agents was similar to that of trovafloxacin. Continued investigation of the NFQ compounds seems to be warranted.

4-Quinolones↗

PubMed1998

Bile duct bacterial isolates in primary sclerosing cholangitis: a study of explanted livers.

BACKGROUND/AIMS: The pathogenesis of the inflammatory lesion in primary sclerosing cholangitis is unknown. The clinical picture is characterized by i.a. episodes of fever, the cause of which also remains speculative. Previous studies of bacterial isolates in the liver or bile ducts in primary sclerosing cholangitis have had the shortcoming of possible contamination associated with the sampling. The aim of this study was to investigate whether bile and bile duct tissue, obtained under sterile conditions in connection with liver transplantation, contain bacteria. METHODS: We studied bile from bile duct walls and bile collected from the explanted livers of 36 patients with primary sclerosing cholangitis and 14 patients with primary biliary cirrhosis. RESULTS: Positive cultures were obtained from 21 of 36 primary sclerosing cholangitis patients, but from none of the primary biliary cirrhosis patients. The number of bacterial strains was inversely related to the time after the last endoscopic retrograde cholangiography. Treatment with antibiotics or intraductal stent, or the occurrence of fever before liver transplantation did not seem to influence the culture results, whereas antibiotic treatment in connection with endoscopic retrograde cholangiography may possibly have reduced the number of isolates in the cultures. Alpha-haemolytic Streptococci were retrieved as late as 4 years after the last endoscopic retrograde cholangiography. Retrospective analysis of liver laboratory tests after endoscopic retrograde cholangiography did not indicate a deleterious effect of the investigation. CONCLUSIONS: The data suggest that antibiotics should be given routinely in connection with endoscopic retrograde cholangiography. They also raise the question of a possible role of alpha-haemolytic Streptococci in the progression of primary sclerosing cholangitis.

Adult↗

PubMed1986

Comparative growth of natural bacterial isolates on various lignin-related compounds.

Bacterial strains were isolated on the basis of their ability to proliferate in a minimal medium containing one of a series of lignin-related compounds as the sole carbon and energy source. These included the aromatic monomers guaiacol, vanillic and coumaric acids, a dimer and a trimer possessing the arylglycerol-beta-aryl ether linkage, anisoin, and both the ether-soluble and -insoluble fractions of kraft lignin. The growth of the strains on each of these compounds was measured. The results showed that the metabolic properties of the strains varied according to the structure of the carbon sources used for their selection. Spectrophotometric tracings of the culture medium during the log phase of growth of one of the strains on the beta-O-4 dimer revealed decomposition with the release of guaiacol.

Journal Article↗

PubMedDate not supplied

Hydrolytic enzymes and surfactants of bacterial isolates from lubricant-contaminated wastewater.

Fifteen bacterial monocultures were isolated from lubricant-contaminated wastewater of an electric power station in Sofia. Six isolates showed best growth in liquid media with 1.5% hexadecane, and on mineral salt agar plates supplemented with one of the following hydrocarbons: n-hexadecane, paraffin, kerosene and samples of wastewater. The ability of all isolates to produce extracellular hydrolytic enzymes and surface-active glycolipids was assessed on the basis of their growth on hydrocarbons. The study of this relatively closed micro-ecosystem revealed the existence of well-balanced microbial consortium where different members have their own role and support each other. On this basis, an alternative approach is proposed for bioaugmented clean up of wastewater contaminated with hydrocarbons and organic polymers using a mixed culture of indigenous bacteria that combines the best producers of glycolipids and hydrolytic enzymes.

Alkanes↗

PubMed2006

Biosorption of nickel and cadmium by metal resistant bacterial isolates from agricultural soil irrigated with industrial wastewater.

Agricultural soil irrigated with industrial wastewater (more than two decades) analysed for heavy metals revealed high levels of Fe, Cr, Cu, Zn, Ni and Cd. Out of a total of 40 bacterial isolates obtained from these soils, 17 belonged to the family enterobacteriaceae and 10 were Pseudomonas spp. A maximum MIC of 200 for Cd, 400 for Zn and Cu, 800 for Ni, and 1600 microg/ml for Pb was observed. Biosorption of Ni and Cd studies over a range of metal ion concentrations with Escherichia coli WS11 both in single and bi-metal systems showed that the adsorption of Cd and Ni was dependent on the concentrations and followed the Freundlich adsorption isotherm. The biosorption of Ni increased from 6.96 to 55.31 mg/g of cells, and Cd from 4.96 to 45.37 mg/g of cells at a concentration ranging from 50 to 400 microg/ml after 2h of incubation in a single metal solution. A further increase in incubation time had no significant effect on the biosorption of metals.

Adsorption↗

PubMed1996

Comparative activity of eight antimicrobial agents against clinical bacterial isolates from the United States, measured by two methods.

In a surveillance study conducted during 1992-1993 at 83 medical institutions of different types and sizes (e.g., laboratories, community hospitals, teaching hospitals) and from different geographical areas of the United States, clinical bacterial isolates were tested for their susceptibility to eight comparative antimicrobial agents (cefepime, ceftazidime, cefotaxime, ceftriaxone, ciprofloxacin, gentamicin, imipenem, and piperacillin). A total of 12,574 isolates were tested by either the Etest method (AB Biodisk) or a microdilution method (MicroScan) in the participating laboratories; 11.8% of these isolates were subsequently retested for quality assurance purposes by both methods in a central laboratory. The results obtained in the central laboratory were essentially the same as the results obtained in the participating laboratories. This article presents data for gram-negative and gram-positive isolates other than Streptococcus pneumoniae, the results of which have been previously published. Antimicrobial susceptibility results obtained with the two different minimum inhibitory concentration (MIC) methods--MicroScan and Etest--showed that most isolates of Enterobacteriaceae were susceptible to cefepime, exceeding the activity of ceftazidime, ceftriaxone, and cefotaxime, principally because of the greater activity of cefepime against the species that produce Bush group 1 beta-lactamases (predominantly Enterobacter cloacae, Enterobacter aerogenes, and Citrobacter freundii). In addition, the activity of cefepime against Pseudomonas aeruginosa isolates was essentially equivalent to that of ceftazidime and greater than that of third-generation cephalosporins. Most methicillin-susceptible Staphylococcus aureus were susceptible to all the cephalosporins, whereas methicillin-resistant S. aureus and enterococci were resistant. Overall, the most active antimicrobials in this study were imipenem, ciprofloxacin, and cefepime, but the activity of all the antimicrobials varied with different species. Categorically, the results from the microdilution and Etest methods were equivalent.

Anti-Bacterial Agents↗

PubMed1986

The metabolism of carbaryl by three bacterial isolates, Pseudomonas spp. (NCIB 12042 & 12043) and Rhodococcus sp. (NCIB 12038) from garden soil.

At an alkaline pH and in aqueous solution, carbaryl hydrolyses to form 1-naphthol, methylamine and carbon dioxide, but it is much more stable at an acid pH. Two bacterial isolated from garden soil, Pseudomonas sp. (NCIB 12042) and Rhodococcus sp. (NCIB 12038), could grow on carbaryl as sole carbon and nitrogen source at pH 6.8 but failed to metabolize carbaryl rapidly. Both could use 1-naphthol as sole carbon source and NCIB 12042 metabolized 1-naphthol via salicylic acid which induced higher expression of enzymes in the pathway. Strain NCIB 12038 metabolized 1-naphthol via salicylic and gentisic acids. In contrast, Pseudomonas sp. (NCIB 12043) was selected in a soil perfusion column enrichment at pH 5.2 and metabolized carbaryl rapidly to 1-naphthol and methylamine. 1-Naphthol was metabolized via gentisic acid. Neither salicylate nor gentisate induced higher expression of enzymes for 1-naphthol catabolism in NCIB 12038 and NCIB 12043.

Carbaryl↗

PubMed2005

[Clinical analysis of reasons for the absence of bacterial isolation in new cases of destructive pulmonary tuberculosis].

Saint Petersburg has been marked by a reduction in the efficiency of Mycobacterium tuberculosis (MBT) detection in the past 5 years. This is suggested by negative changes in the ratio of the rate of detected bacterial isolation to the phase of lung decay in new cases of tuberculosis. This is largely due to the fact that before treatment, clinicians do not fulfil in full measure the regulated requirements for the choice of studies and for the frequency of examinations for MBT. Sampling for microbiological studies is made, by infringing the technological specifications. Highly informative methods for MBT detection are not frequently used in the above cases. This all hampers diagnosis and rational treatment in these patients.

Bronchoscopy↗

PubMed2026

A culture collection of bacterial isolates from Lake Erie and Lake Victoria.

We present a culture collection of 44 aquatic bacterial cultures isolated from samples collected from Lake Erie's Sandusky and Maumee Bays and Lake Victoria's Winam Gulf. Here, we detail isolation, cryopreservation, and genomic DNA preparation methods and sequences of full-length 16S rRNA genes.

Great Lakes↗