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M J Ferraro

Publications and source records attributed to M J Ferraro.

At least 73 records · Page 4Linked to original sources

Species identities of enterococci isolated from clinical specimens.

Conventional tests and commercially available systems were used to determine the species identities of clinical isolates of enterococci. Strict adherence to the conventional test scheme of Facklam and Collins (R. R. Facklam and M. D. Collins, J. Clin. Microbiol. 27:731-734, 1989) resulted in the misidentification of lactose-negative Enterococcus faecalis isolates as Enterococcus solitarius, but this problem was overcome by the application of additional tests. The commercially available systems tested were unable to recognize some of the more recently described enterococcal species. E. faecalis accounted for 87.1% of 302 consecutive isolates. Enterococcus faecium (8.6%), Enterococcus avium (0.7%), Enterococcus durans (0.3%), Enterococcus gallinarum (1.0%), Enterococcus casseliflavus (1.0%), Enterococcus hirae (0.3%), and Enterococcus raffinosus (0.3%) isolates were also identified. None of the isolates produced beta-lactamase, but 15.4% of 235 isolates tested, including 1 strain of E. gallinarum, displayed high-level resistance to gentamicin.

Culture Media↗

Use of commercially available rapid chloramphenicol acetyltransferase test to detect resistance in Salmonella species.

Chloramphenicol resistance among Salmonella spp. has important public health and clinical implications, especially in areas of the world where these strains are endemic. The availability of rapid and sensitive screening methods for detection of antibiotic resistance is important. Therefore, we tested 33 strains of Salmonella for chloramphenicol acetyltransferase (CAT) activity using two rapid techniques. Evaluation of a 1-h tube method and a 30-min commercial disk procedure demonstrated that they are as accurate as standardized susceptibility techniques. Both the 1-h tube and 30-min disk methods detected CAT enzymatic activity produced by one CAT gene copy per cell.

Chloramphenicol O-Acetyltransferase↗

Frozen musculoskeletal allografts. A study of the clinical incidence and causes of infection associated with their use.

A retrospective study was performed to determine the clinical incidence and causes of infection related to the use of frozen musculoskeletal allografts. The results of this study of 324 grafts, prepared and supplied by our hospital bone bank, showed that the patients in whom femoral head grafts and other small bone and soft-tissue allografts were used had a negligible clinical incidence of infection. The incidence of infection related to the use of large allografts, such as osteoarticular or diaphyseal grafts, was approximately 5 per cent in patients who had treatment for a bone tumor and 4 per cent in those who had revision of a hip arthroplasty. These rates of infection were not substantially different from those that have been reported in similar series in which large allografts or sterilized prosthetic devices were used. The causes of the infections were difficult to determine, but contamination of the allograft was probably not a factor in most patients.

Anti-Bacterial Agents↗

Effect of varying pH on the susceptibility of Campylobacter pylori to antimicrobial agents.

The susceptibility of 22 clinical isolates of Campylobacter pylori to eight antimicrobial agents was studied under varying pH conditions. Macrolides (erythromycin, dirythromycin), clindamycin and to a lesser extent quinolones lost efficacy at lowered pH. The activity of ampicillin and metronidazole remained relatively stable throughout the pH range tested. The effect of pH an antimicrobial efficacy may warrant consideration when selecting an antibiotic to clear Campylobacter pylori in vivo, since the pH of the gastric submucous environment is not known for certain.

Anti-Bacterial Agents↗

In vitro activity of cefoperazone-sulbactam combinations against cefoperazone-resistant clinical bacterial isolates.

From July 1987 to January 1988, 452 cefoperazone-resistant bacterial isolates were identified among strains subjected to routine susceptibility testing in a clinical microbiology laboratory. The 452 isolates were tested for susceptibility to cefoperazone, sulbactam, and a 2:1 combination of these drugs by agar dilution techniques. The greatest benefit of the cefoperazone-sulbactam combination was noted against Bacteroides spp. and Acinetobacter spp. The combination demonstrated clinically significant synergism against approximately 20% of strains of Pseudomonas aeruginosa.

Acinetobacter↗

Comparative in vitro activity of SM7338, a new carbapenem antimicrobial agent.

The comparative in vitro activity of SM7338 was tested against 670 routine clinical isolates and 130 cefoperazone-resistant isolates of bacteria by agar dilution methods. SM7338 was at least as active as imipenem against gram-negative organisms but was slightly less active against gram-positive organisms. SM7338 was particularly active against members of the family Enterobacteriaceae, with MICs for 90% of strains of less than or equal to 0.125 micrograms/ml for all species tested. Differences in activity between SM7338 and imipenem were particularly striking against Proteus vulgaris, Proteus mirabilis, and Morganella morganii, against which MICs of SM7338 and imipenem for 90% of strains were 0.125 and 4 micrograms/ml, respectively. The presence of unique plasmid-mediated beta-lactamases in Pseudomonas aeruginosa PU21 transconjugants did not affect activity substantially, except in the case of OXA-2 (eightfold-increased MIC) and OXA-3 (fourfold-increased MIC). SM7338 was also active against a laboratory-derived strain of P. aeruginosa which hyperproduced chromosomal beta-lactamase, inhibiting both the wild type and the mutant at a concentration of 1.0 micrograms/ml.

Anti-Bacterial Agents↗

In vitro activities of daptomycin and other antimicrobial agents against vancomycin-resistant gram-positive bacteria.

A comparative evaluation of daptomycin and eight other antimicrobial agents was performed by the agar dilution technique with 56 strains of vancomycin-resistant gram-positive bacteria, including Leuconostoc, Lactobacillus, and Pediococcus spp. Erythromycin, deptomycin, clindamycin, and gentamicin exhibited the greatest activities, whereas penicillin, ampicillin, and cefotaxime showed moderate activities. The organisms were all highly resistant to vancomycin and cefoxitin.

Anti-Bacterial Agents↗

Bacteremia with Streptococcus bovis and Streptococcus salivarius: clinical correlates of more accurate identification of isolates.

Two biotypes of Streptococcus bovis can be identified by laboratory testing and can be distinguished from the phenotypically similar organism Streptococcus salivarius. We assessed the clinical relevance of careful identification of these organisms in 68 patients with streptococcal bacteremia caused by these similar species. S. bovis was more likely to be clinically significant when isolated from blood (89%) than was S. salivarius (23%). There was a striking association between S. bovis I bacteremia and underlying endocarditis (94%) compared with that of S. bovis II bacteremia (18%). Bacteremia with S. bovis I was also highly correlated with an underlying colonic neoplasm (71% of patients overall, 100% of those with thorough colonic examinations) compared with bacteremia due to S. bovis II or S. salivarius (17% overall, 25% of patients with thorough colonic examinations). We conclude that careful identification of streptococcal bacteremic isolates as S. bovis biotype I provides clinically important information and should be more widely applied.

Adolescent↗

Vancomycin-resistant gram-positive bacteria isolated from human sources.

Recent reports of infections with vancomycin-resistant gram-positive bacteria prompted us to study vancomycin-resistant isolates from human sources to characterize the types of bacteria displaying this phenotype. Thirty-six vancomycin-resistant gram-positive isolates, 14 from clinical specimens and 22 from stool samples, were identified. These isolates were tentatively identified as Lactobacillus spp. (25 strains), Leuconostoc spp. (6 strains), and Pediococcus spp. (3 strains) on the basis of morphology and physiological tests. Two isolates of indeterminate morphology could not be unambiguously assigned to a genus. Four isolates of vancomycin-resistant lactobacilli from normally sterile body sites were considered to be clinically significant. Vancomycin-resistant gram-positive bacteria may represent an emerging class of nosocomial pathogens. Better methods for distinguishing the various genera in the clinical microbiology laboratory are needed.

Adult↗

Routine culture of stool specimens for Yersinia enterocolitica is not a cost-effective procedure.

Cefsulodin-Irgasin-novobiocin (CIN) agar was used to isolate Yersinia enterocolitica from 3,622 stool specimens received in our laboratory during a 1-year period. Seven specimens (0.2%) yielded Y. enterocolitica strains from a total of five patients. The low frequency of Y. enterocolitica isolation observed, coupled with the isolation of this pathogen from three of the five patients by our standard stool examination protocol, leads us to conclude that routine culture of stool specimens on CIN agar is not a cost-effective procedure.

Cost-Benefit Analysis↗

Simple microbiologic detection of Campylobacter pylori.

A study of 84 gastric biopsies taken from 42 adult patients revealed simple techniques for Gram stain and culture for Campylobacter pylori. In an initial study of 18 biopsies, Gram stains prepared from ground, diluted tissue were all negative for curved, gram-negative rods, whereas 13 of these specimens were positive for C. pylori by culture. The Gram stains for the remaining 66 biopsies were prepared by a rinse-imprint technique. In this group, there were 30 Gram stains positive for organisms resembling C. pylori and 32 positive cultures. By Gram-staining two sites, fundus and antrum, the sensitivity of the Gram stain for identifying a positive specimen increased from 91 to 100%. Gram stain may be the preferred technique for rapid diagnosis. When cultured, C. pylori was recovered most often on modified Thayer-Martin medium incubated microaerophilically at 35 degrees C. The presence of antibiotics in modified Thayer-Martin medium limited upper respiratory flora overgrowth, which was often present on nonselective media.

Biopsy↗

Comparative in-vitro activity of A-56268 (TE-031), a new macrolide antibiotic.

The comparative in-vitro activity of A-56268 (TE-031), a new semisynthetic macrolide antibiotic, was assessed against approximately 400 bacterial isolates. The new drug demonstrated excellent activity against penicillin-susceptible streptococci (MIC90s less than or equal to 0.06 mg/l) and methicillin-susceptible staphylococci (MIC90 = 0.25 mg/l). Among other Gram-positive organisms tested, a significant number were resistant to A-56268 as well as to erythromycin and clindamycin. A-56268 was at least as active as erythromycin against Pasteurella multocida and Campylobacter jejuni, but was more active than erythromycin against Legionella spp. (MIC90 less than or equal to 0.06 mg/l), Bacteroides fragilis (MIC90 = 4 mg/l) and Bact. melaninogenicus (MIC90 less than or equal to 0.125 mg/l). Activity of A-56268 was pH dependent (more active at pH 7 than at pH 6) and was moderately affected by inoculum size. The drug was bactericidal against two strains of Streptococcus pyogenes tested, but exerted a bacteriostatic effect against Staphylococcus aureus and Str. faecalis.

Anti-Bacterial Agents↗

Hydrolytic enzymes of "Streptococcus milleri".

Seventy-two isolates classified as "Streptococcus milleri" were examined for the presence of various hydrolytic enzymes. While no protein or lipid-degrading activities were demonstrated, some isolates showed DNase and mucopolysaccharide-degrading activities. Beta-hemolytic isolates were more likely to produce these enzymes than were nonhemolytic strains. Isolates of one "S. milleri" biotype (mannitol fermentation positive) were uniformly devoid of all enzyme activities tested.

Chondroitinases and Chondroitin Lyases↗

Comparison of a new, rapid enzyme immunoassay with a latex agglutination test for qualitative detection of rubella antibodies.

A total of 450 sera were tested for rubella virus antibodies by using a new, rapid enzyme immunoassay, SUDS Rubella. The results were compared with those obtained by using the Rubascan test, a well-established latex agglutination method. The sensitivity of the SUDS Rubella was 99.5%, and the specificity was 100%, when compared with Rubascan. The SUDS Rubella test can be performed in 10 min and provides an accurate screening test for the detection of rubella antibodies.

Antibodies, Viral↗

Effect of diagnosis-related groups on diagnostic methodology in the hospital laboratory.

Traditionally physicians have ordered clinical laboratory tests for a variety of reasons. The establishment of a federally mandated prospective payment system for Medicare patients based on diagnosis-related groups has, among other things, necessitated a review of these reasons as well as the level of use of clinical laboratory services for a given diagnosis. Diagnosis-related group payment to hospitals is independent from the number of laboratory studies performed as long as the diagnosis-related group diagnosis is substantiated at the time the patient is discharged from the hospital. The cost-effective utilization of present tests as well as the adoption of new diagnostic methodologies depends on the assessment of whether a test possesses the appropriate parameters to be of sufficient diagnostic value. These factors include sensitivity, specificity, prevalence, speed, and the costs associated with false-negative or false-positive results. The assessment of the diagnostic value of present or future laboratory methods will require careful analysis relative to their financial impact both within the laboratory and for the hospital as a whole. The laboratory's knowledge of the diagnosis-related group accounting for the highest percentage of their hospital's costs, the highest volume of their cases, and the highest use of their services can aid in assessment of the appropriateness and level of laboratory services. An analysis of the percentage of microbiology costs associated with these diagnosis-related group categories for a large, tertiary care hospital is discussed.

Adolescent↗

Presumptive identification of "Streptococcus milleri" in 5 h.

Rapid miniaturized tests for acetoin production, arginine hydrolysis, and sorbitol fermentation were used for presumptive identification of non-beta-hemolytic "Streptococcus milleri" isolates in 5 h. All 77 "S. milleri" strains tested were Voges-Proskauer positive, arginine hydrolysis positive, and sorbitol fermentation negative. On the basis of these reactions, "S. milleri" was differentiated from isolates of other viridans group streptococcal species and from Streptococcus bovis.

Acetoin↗

Potential impact of rapid microbiology tests in the prospective payment era.

The potential impact of rapid microbiology tests in the prospective payment era is complex and difficult to assess. Although several of the newer methods have been shown to speed detection, isolation, and susceptibility testing of clinical isolates, many of these improvements come only at an additional cost to the microbiology laboratory. Decisions as to whether it is cost-effective to implement these tests may necessitate an analysis at three separate but interdependent levels: level 1--laboratory costs, level 2--hospital costs, and level 3--morbidity and mortality. Within each of these levels, cost offsets associated with a variety of factors may be identifiable. These factors should be carefully evaluated before implementing new methodologies in the microbiology laboratory.

Bacterial Infections↗