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M G Cormican

Publications and source records attributed to M G Cormican.

36 records · Page 2Linked to original sources
PubMed1995

Cross-resistance analysis for DU-6859a, a new fluoroquinolone, compared to six structurally similar compounds (ciprofloxacin, clinafloxacin, fleroxacin, levofloxacin, ofloxacin, and sparfloxacin).

Emerging resistance to the current fluoroquinolones has encouraged synthesis of new compounds in this class. We have evaluated the activity of DU-6859a, a novel halogenated quinolone, against a panel of 300 bacteria, relative to the activity of ciprofloxacin, clinafloxacin, fleroxacin, levofloxacin, ofloxacin, and sparfloxacin. DU-6859a was the most active of the fluoroquinolones studied and retains potentially useful activity against 80% of isolates resistant (minimum inhibitory concentration, > or = 4 micrograms/ml) to ciprofloxacin. Continued clinical investigation of DU-6859a and similar new quinolones is urged.

Anti-Infective Agents↗
PubMed1995

Reevaluations of disk diffusion susceptibility testing interpretive criteria for lomefloxacin and norfloxacin using fluoroquinolone-resistant isolates.

The current National Committee for Clinical Laboratory Standards interpretive criteria for disk diffusion susceptibility testing of lomefloxacin and norfloxacin were reevaluated using a test panel of 298 bacteria (200 with ciprofloxacin minimum inhibitory concentrations (MICs) at > or = 4 micrograms/ml). MICs were correlated with the diameter of zones of inhibition by regression statistics and error-rate bounding methods. Modifications of the interpretive criteria for lomefloxacin disk susceptibility testing are proposed as follows: susceptible at > or = 20 mm and resistant at < or = 16 mm, a 2-mm decrease of existing break-point zones. These criteria result in an absolute interpretive agreement of 95.3% with a very major (false susceptible) error rate of only 0.7%. The currently used criteria for norfloxacin (susceptible at > or = 16 mm and resistant at < or = 13 mm) were validated, and these break-points had an absolute interpretive correlation between methods of 91.9%. The change proposed for lomefloxacin disk interpretations would minimize minor and major errors most often reported for Staphylococcus saprophyticus isolates.

Anti-Infective Agents↗
PubMed1995

Preliminary interpretive criteria for disk diffusion susceptibility testing of SCH 27899, a compound in the everninomicin class of antimicrobial agents.

As antimicrobial resistance among Gram-positive species becomes more common, alternative agents need to be developed for the therapy of serious infections. SCH 27899 is a compound from the everninomicin class of antimicrobial agents that possesses a potent Gram-positive spectrum. We evaluated three disk concentrations (0.25, 1, and 5 micrograms) of three SCH 27899 formulations including SCH 27899 base (SCHB), N-methylglucamine SCH 27899 (NMG-SCH), and NMG-SCH complexed with hydroxypropyl beta-cyclodextrin. Disk zone diameters were correlated with minimum inhibitory concentration for 209 aerobic, nonfastidious Gram-positive strains and selected Gram-negative bacilli to develop disk diffusion interpretive criteria. No significant differences in activity were noted among the three SCH 27899 preparations. Of the three disk concentrations, the correlation coefficient was greatest (r = 0.88) for the 5-micrograms SCHB disk test. For a tentative break point of < or = 2 micrograms SCHB/ml, preliminary disk interpretive criteria were: susceptible at > or = 12 mm, intermediate at 10-11 mm, and resistant at < or = 9 mm (absolute categorical agreement, 99.5%). Zones were small secondary to drug solubility and diffusion limitations. Using these criteria for the SCHB 5-micrograms disks, nearly all of the tested Gram-positive organisms were susceptible including methicillin-resistant staphylococci and vancomycin-resistant enterococci.

Aminoglycosides↗
PubMed1995

Evaluation of the in-vitro activity of furopenem (SY5555 or SUN5555) against respiratory tract pathogens and beta-lactamase producing bacteria.

Furopenem is a novel orally active penem. In this study, furopenem was highly active in vitro against Streptococcus pneumoniae (MIC90 0.03 mg/L), Haemophilus influenzae (MIC90, 2 mg/L), and Moraxella catarrhalls (MIC90, 0.5 mg/L). Its activity was not reduced by a variety of beta-lactamase enzymes, however beta -lactam resistance by other mechanisms was associated with higher MICs.

Bacteria↗
PubMed1995

Cross-resistance analysis for clinafloxacin compared with ciprofloxacin, fleroxacin, ofloxacin, and sparfloxacin using a predictor panel of ciprofloxacin-resistant bacteria.

Clinafloxacin was significantly more active against fluoroquinolone-resistant organisms than ciprofloxacin, ofloxacin, sparfloxacin and fleroxacin. Clinafloxacin inhibited 65% of isolates at the recommended breakpoint (< or = 1 mg/L) compared with only 30.0% for ciprofloxacin, 31.7% for ofloxacin, 32% for fleroxacin, and 37.7% for sparfloxacin at their recommended breakpoints. No strain susceptible to ciprofloxacin was resistant to the other compounds tested.

Anti-Infective Agents↗
PubMed1995

Susceptibility to levofloxacin predicted from in vitro susceptibility testing results obtained with ciprofloxacin and with ofloxacin.

A test battery of bacterial strains with a high incidence of resistance to fluoroquinolones was studied to determine the extent to which susceptibility to levofloxacin could be predicted from susceptibility tests performed with ciprofloxacin or ofloxacin as reagents. Isolates susceptible or intermediately susceptible to ofloxacin (MICs < or = 4 micrograms/ml) may be regarded as susceptible to levofloxacin, with the exception of Enterococcus faecium. Ciprofloxacin-susceptible isolates (MICs < or = 1 micrograms/ml) were also completely susceptible to levofloxacin. Clinical laboratories could use either of the currently used fluoroquinolones (ciprofloxacin or ofloxacin) to predict levofloxacin activity and spectrum with little risk of false-susceptible errors (0.0 to 1.3%). Results obtained with ofloxacin are superior in maximizing recognition of levofloxacin-susceptible clinical isolates.

Bacteria↗
PubMed1995

In vitro activity of levofloxacin and FK-037 against aerobic isolates from spontaneous bacterial peritonitis.

Spontaneous bacterial peritonitis is a potentially fatal complication of ascites, most often caused by the Enterobacteriaceae or streptococci. We have evaluated the in vitro activity of FK-037, a new cephalosporin, cefotaxime, cefpirome, ceftazidime, levofloxacin, and ofloxacin against a collection of 124 isolates from patients with spontaneous bacterial peritonitis. Levofloxacin (< or = 2 mg/L) was active against all isolates and ofloxacin (< or = 2 mg/L) against 98.4% of isolates. The cephalosporins (< or = 8 mg/L) were less active against cefpirome = 95.4%, FK-037 = 94.4%, and cefotaxime and ceftazidime = 91.1%. Given the high mortality associated with spontaneous bacterial peritonitis, clinical studies of the quinolones (specifically of levofloxacin) and the alternative cephalosporins presented for treatment of spontaneous bacterial peritonitis appears warranted.

Anti-Bacterial Agents↗
PubMed1994

PCR based fingerprinting of Enterobacter cloacae.

An outbreak of lower respiratory tract infection with Enterobacter cloacae occurred in an intensive care unit in a university teaching hospital. Random amplification of polymorphic DNA (RAPD) was used to assist in the investigation of the outbreak. The technique was readily applied to this organism and permitted differentiation between strains which had identical biochemical profiles and antibiograms. The versatility of this technique makes it attractive for use in hospitals where fingerprinting of any one of the many Gram-negative rods associated with nosocomial infection may be required from time to time.

Cross Infection↗
PubMed1992

Tuberculosis in the west of Ireland 1986-1990.

A review of mycobacteria isolated from clinical samples from the Western Health Board Area (WHBA) for the years 1986 to 1990 was performed to establish the pattern of mycobacterial infection. The incidence of microbiologically proven cases of tuberculosis (13.3/100,000) and of sputum smear positive cases (6.2/100,000) was determined and correlated with notification data. M. bovis accounts for 6.3% of cases of microbiologically confirmed tuberculosis in this area. Resistance to one or more of the first line anti-tuberculous drugs was noted in 5.3% of isolates (excluding pyrazinamide resistance in M. bovis). Clinically significant isolates of mycobacteria other than tuberculosis (MOTT) were rare throughout the five year period. The overall incidence of microbiologically proven cases of tuberculosis is relatively high and M. bovis and drug resistant isolates of M. tuberculosis are relatively common.

Drug Resistance, Microbial↗
PubMed1992

Use of polymerase chain reaction for early identification of Mycobacterium tuberculosis in positive cultures.

AIMS: To develop a readily applicable polymerase chain reaction (PCR) based technique which would permit the identification of Mycobacterium tuberculosis complex isolates from Bactec phials at an earlier stage than currently available methods. METHODS: Mycobacterial cells cultured in Bactec 12B medium were harvested by centrifugation. The cells were lysed by heating in distilled water. Oligonucleotide primers based on the sequence of the gene coding for the immunogenic protein MPB64 were then used to amplify a 240 base pair fragment of DNA directly from the crude cell lysate. The PCR product was visualised under ultraviolet light following electrophoresis of an aliquot in an agarose gel containing ethidium bromide. The sensitivity of the PCR was adjusted so that about 600 cfu of M tuberculosis gave a positive result. The lowest growth index at which this method of identification might be applied to Bactec phials was determined and a number of routine cultures giving a positive growth index examined. RESULTS: M tuberculosis was positively identified at the lowest growth index, as determined by the Bactec system. Of 45 routine cultures examined, with growth indexes ranging from 6 to 999, the 15 confirmed by conventional means to contain M tuberculosis were correctly identified from 1 ml of culture medium. CONCLUSIONS: The method described can be used to identify M tuberculosis isolates cultured in the Bactec system at the earliest detectable rise in growth index. It may therefore allow cultured mycobacteria to be identified at an earlier stage than conventional methods or the commercially available DNA probes adapted for use with the Bactec system.

Base Sequence↗
PubMed1991

The microbial flora of in-use blood pressure cuffs.

The capacity of blood pressure cuffs to act as vehicles of hospital infection has been recognised. We describe the microbial flora of in-use DINAMAP blood pressure cuffs used in the operating theatres and one recovery room in a teaching hospital. Our results show significant microbial contamination of in-use blood pressure cuffs.

Bacteria↗
PubMedDate not supplied

Comparative antimicrobial activity and spectrum of CP-99,219, a novel fluoroquinolone, tested against ciprofloxacin-resistant clinical isolates.

The fluoroquinolones have an established role in treatment of infection with aerobic gram negative rods. The increased importance of gram positive nosocomial infection and of acquired fluoroquinolone resistance has stimulated a search for new compounds with enhanced potency and spectrum. CP-99,219 is a novel compound in this class with enhanced activity against gram positive organisms. We have studied the activity of CP-99,219 relative to ciprofloxacin, fleroxacin, ofloxacin, and sparfloxacin using test panels of organisms with a high proportion of ciprofloxacin resistance. CP-99,219 is more potent than any of the other four compounds against both gram positive and gram negative bacteria. The activity of CP-99,219 against many bacteria resistant to the established agents, warrants further in vitro and clinical studies.

Acinetobacter↗
PubMedDate not supplied

Antimicrobial activity of cefotaxime tested against infrequently isolated pathogenic species (unusual pathogens).

The cefotaxime sodium spectrum of activity is very broad and includes many common species and a variety of less frequently isolated pathogens. We have reviewed the clinical microbiology literature (44 references) and the data base of the University of Iowa Hospitals and Clinics (Iowa City, IA) to collect data on the activity of cefotaxime against the less common species. Cefotaxime was consistently active against Actinobacillus actinomycetemcomitans, Capnocytophaga spp., Eikenella corrodens, Erysipelothrix rhusiopathiae, Pasteurella multocida, Plesiomonas shigelloides, and Fusobacterium nucleatum. The species Alcaligenes xylosoxidans, Flavobacterium spp., Stenotrophomonas (Xanthomonas) maltophilia, Bacillus cereus, Listeria monocytogenes, and Rhodococcus equi were uniformly cefotaxime resistant. For many other species there was considerable variation in reported minimum inhibitory concentrations. These data may be helpful in guiding therapy of unusual infections, particularly in the case of fastidious species, where the appropriate susceptibility testing methodology may not be immediately or routinely available.

Bacteria, Anaerobic↗
PubMedDate not supplied

Bactericidal activity of cefotaxime, desacetylcefotaxime, rifampin, and various combinations tested at cerebrospinal fluid levels against penicillin-resistant Streptococcus pneumoniae.

Penicillin resistance is increasingly prevalent amongst clinical isolates of Streptococcus pneumoniae. Recently, isolates resistant to the extended-spectrum cephalosporins have also begun to emerge, and combination therapy may be necessary for infection with such organisms. We have studied the activity of cefotaxime, ceftriaxone, ceftazidime, rifampin, chloramphenicol, and vancomycin against 10 S. pneumoniae strains with penicillin minimum inhibitory concentrations (MICs) ranging from 0.03-8 micrograms/ml. The bactericidal activity of cefotaxime, desacetylcefotaxime, rifampin, and combinations of these agents (cerebrospinal fluid levels) against these isolates was determined. Elevated MICs to penicillin were associated with generally twofold lower cefotaxime MICs. All strains remained susceptible to vancomycin and rifampin. The bactericidal activity of cefotaxime with or without desacetylcefotaxime was reduced by the addition of rifampin. Pneumococcal isolates with penicillin MICs of < or = 1 microgram/ml were slowly killed by cefotaxime alone or with desacetycefotaxime. At present, there is little evidence to support the addition of rifampin to cefotaxime for therapy of meningitis.

Anti-Bacterial Agents↗