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Biomedical subjects

S M Markowitz

Publications and source records attributed to S M Markowitz.

At least 55 records · Page 3Linked to original sources

An analysis of blood and body fluid exposures sustained by house officers, medical students, and nursing personnel on acute-care general medical wards: a prospective study.

OBJECTIVE: To prospectively examine the epidemiology of blood and body fluid exposures sustained by medicine housestaff, medical school students, registered nurses (RNs), licensed practical nurses (LPNs), and nurses' aides (NAs) on general medicine wards and to define problem areas that may be amenable to change. DESIGN: Daily data collection during 9 months using a self-reporting questionnaire. SETTING: General medical wards in 2 tertiary referral hospitals. PARTICIPANTS: Medicine housestaff/students and nursing personnel. RESULTS: Physicians reported 644 exposures, of which 98 (15.2%), 296 (46.0%), and 250 (38.8%) were sustained by medicine residents, interns, and students, respectively. Blood contact occurred with 591 (91.8%) exposures. For physicians, 575 (89.3%) exposures occurred during venipuncture, intravenous catheter manipulation, and arterial punctures. Interns and students most commonly incurred exposures during venipunctures and intravenous manipulations; residents commonly were exposed during emergent intravenous catheter placements. Five-hundred-twenty-two (81%) exposures occurred between 7 A.M. and 7 P.M. During 524 (81.4%) exposures, physicians were not using barrier devices. Nurses reported 235 exposures, of which 140 (59.6%), 23 (9.8%), and 72 (30.6%) were sustained by RNs, LPNs, and NAs, respectively. RN exposures commonly occurred during intravenous manipulations and glucometer fingersticks. LPNs and NAs incurred a higher percentage of exposures during nonprocedural patient care. Blood contact and wound drainage accounted for 167 (71.1%) and 31 (13.2%) exposures, respectively. CONCLUSIONS: Exposures to blood and body fluids frequently are incurred by healthcare workers on general medical wards. Efforts to reduce these exposures should be directed not only at improving procedural skills of healthcare workers for venipunctures, intravenous catheter insertions, and glucometer fingersticks, but also in increasing barrier use during procedural and nonprocedural tasks.

Blood↗

Evidence for clonal spread of a single strain of beta-lactamase-producing Enterococcus (Streptococcus) faecalis to six hospitals in five states.

Beta-lactamase-producing (Bla+) enterococci have been reported in three state and two countries. Pulsed-field gel electrophoresis was used to compare 14 Bla+ Enterococcus (Streptococcus) faecalis isolated from hospitalized patients in seven states and three continents. The restriction endonuclease digestion patterns of isolates from Connecticut, Massachusetts, Lebanon, and Argentina were all markedly different, indicating that these were different strains. However, isolates from Delaware, Texas, Pennsylvania (Philadelphia and Pittsburgh), Florida, and Virginia were similar, indicating that these isolates were derivatives of a single strain. This conclusion was supported by hybridization using individual fragments as probes. Spread of Bla+ enterococci within the hospital setting was also demonstrated. These findings illustrate the value of pulsed-field gel electrophoresis for epidemiologic analyses and support the importance of identifying and containing organisms with new resistance properties in an effort to decrease their transmission to and from, as well as within, hospitals.

Argentina↗

Antimicrobial susceptibility and molecular epidemiology of beta-lactamase-producing, aminoglycoside-resistant isolates of Enterococcus faecalis.

beta-Lactamase-producing (BL+), aminoglycoside-resistant (AR) Enterococcus faecalis is endemic in our hospital, having caused widespread colonization and infection. Suitable therapy for infections caused by these organisms has been problematic. We compared the antimicrobial and bactericidal activities, by broth macrodilution and time-kill methods, of several antibiotics, alone and in combination, against BL+, AR isolates of E. faecalis and determined the transmissibility of antibiotic resistance markers. Ampicillin-sulbactam, imipenem, daptomycin, and ciprofloxacin were the most active antibiotics with MICs for 90% of isolates tested of 2, 1, 2, and 1 microgram/ml, respectively, against inocula of 10(3) and 10(5) CFU/ml. Little inoculum effect was noted with imipenem, vancomycin, daptomycin, or ciprofloxacin, while the addition of sulbactam to ampicillin partially inhibited the effect of the increased inoculum. Penicillin-sulbactam and ampicillin-sulbactam combinations in a 2:1 ratio were most frequently bactericidal (greater than or equal to 3-log10-unit decrease in bacterial titers at 24 h for 13 of 20 isolates), followed by daptomycin (8 of 20 isolates) and ciprofloxacin (2 of 20 isolates). Bactericidal activity was not demonstrated for imipenem or teicoplanin. beta-Lactamase production and aminoglycoside resistance were associated with a 60- to 65-MDa plasmid which was easily transferred to a plasmid-free E. faecalis recipient. The 840-bp beta-lactamase gene probe hybridized to purified plasmid DNA from BL+ donor isolates of E. faecalis and transconjugants but not from BL- isolates. Ampicillin-sulbactam and daptomycin (an investigational antibiotic) seem to be reasonable choices for the empiric therapy of presumed enterococcal infections in hospitals in which BL+, AR E. faecalis strains are isolated. Their use should ideally be supported by tests for bactericidal activity.

Aminoglycosides↗

Pneumonia and empyema infection associated with a Bacillus species that resembles B. alvei.

An organism resembling Bacillus alvei was isolated from the lung and pleural fluid of an immunocompetent patient. The isolate differed from the type strain of B. alvei in its ability to reduce nitrate and its inability to produce dihydroxyacetone and acetylmethylcarbinol. The isolate was resistant to ciprofloxacin and showed intermediate susceptibility to vancomycin.

Bacillaceae Infections↗

A prospective study of the clinical utility of lymphocyte monitoring in the cardiac transplant recipient.

Monitoring peripheral lymphocytes for changes in antigen expression or subpopulations was performed by flow cytometry in an attempt to identify infection or rejection in cardiac transplantation recipients (CTRs). In this study, 32 cardiac transplantation recipients were followed prospectively, and the results of 274 lymphocyte analyses for transferrin receptor expression, an indicator of lymphocyte activation, and CD4/CD8 lymphocyte ratios were correlated with the patient's clinical status, e.g., infection (early or late), rejection (mild, moderate, or severe), or quiescence. The percentage of lymphocytes expressing the transferrin receptor (%TR+) increased significantly during all stages of infection (2.9%, P = 0.02), or stratified into early (2.7%, P = 0.03) or late stage infection (2.6%, P = 0.03). The increase in %TR+ lymphocytes was also noted during mild (2.8%, P = 0.01) and moderate (3.0%, P = 0.008) rejection. The specificity and positive predictive value of an increased %TR+ lymphocyte was 97% and 93%, respectively, during early infection; 92 and 71%, respectively, during mild rejection; and 85 and 80%, respectively, during moderate rejection. The CD4/CD8 lymphocyte ratio did not correlate with either infection or rejection (P greater than 0.05). In conclusion, an increase in the %TR+ lymphocytes indicates the presence of infection, especially acute infection, or, less likely, rejection in the cardiac transplant recipient, but its clinical utility may be as a screening test for the presence of infection, especially early infection in CTRs during the posttransplantation period. The CD4/CD8 lymphocyte ratio does not correlate with the presence of infection or rejection in the CTR.

Antigens, Differentiation, T-Lymphocyte↗

Native valve endocarditis caused by an organism resembling Corynebacterium striatum.

An organism resembling Corynebacterium striatum was isolated from the blood of a patient with acute aortic valvular insufficiency and no history of valvular heart disease. At autopsy, histopathologic examination of the aortic valve revealed pleomorphic gram-positive bacilli and destruction of valvular tissue. Our isolate differed from other nondiphtherial corynebacteria, including the type strain of C. striatum (ATCC 6940), in its ability to reduce nitrite. Nitrite reduction may be useful for distinguishing strains of corynebacteria.

Aged↗

Biliary obstruction and cholestasis in AIDS: case report.

In summary, we have described a patient with AIDS and a previously unreported cause of biliary tract obstruction. The incidence of cryptococcal visceral lymphadenitis in patients with AIDS and disseminated cryptococcosis is unknown, but, if present, is probably clinically silent in most instances. However, in the differential diagnosis of abdominal pain and cholestasis in such patients, one should consider major biliary duct obstruction due to cryptococcal lymphadenitis.

Acquired Immunodeficiency Syndrome↗

Disseminated coccidioidomycosis. Unusual manifestations in a cardiac transplantation patient.

Because of the immunosuppressive therapy received by patients undergoing cardiac transplantation, disseminated infections, including disseminated fungal infections, often develop. Disseminated coccidioidomycosis developed in a 23-year-old man soon after undergoing orthotopic cardiac transplantation. Clinical manifestations included an unusual rash, severe myositis and arthropathy, a rapid downhill course, and pathologic evidence of widespread fungal invasion, including invasion of the cardiac graft. Detailed travel and geographic histories, and perhaps skin testing and antibody determinations for geographic-specific pathogens, should be part of the preoperative evaluation of all transplant candidates.

Adult↗

Isolation of Stomatococcus mucilaginosus from drug user with endocarditis.

Stomatococcus mucilaginosus was isolated from the blood of a patient with endocarditis and a past history of drug abuse and aortic valve replacement. At autopsy, Gram stain of the aortic valve revealed gram-positive cocci. Our isolate was atypical for S. mucilaginosus in that colonies were nonmucoid and nonadherent to agar surfaces. Cellular capsules were demonstrated by light and electron microscopy. Phenotypic characteristics identified by conventional methods as well as profile numbers obtained by using two commercial identification systems for staphylococci, the API Staph-Ident and the dms Staph Trac, are presented. Practical tests that differentiate S. mucilaginosus from the genera Micrococcus and Staphylococcus include growth on nutrient agar containing salt and lysostaphin susceptibility. Additional tests that helped differentiate our isolate from group D streptococci included hydrolysis of L-pyrrolidonyl-beta-naphthylamide and streptococcal serogrouping.

Adult↗

Echovirus meningomyeloencephalitis with administration of intrathecal immunoglobulin.

Echovirus meningomyeloencephalitis was treated with cerebral intraventricular immunoglobulin. This case includes a complete examination of the central nervous system (CNS) supported by viral culture studies, immunoperoxidase staining and electron microscopy. Neuronal loss was most severe in the cerebellum and spinal cord. This may lead to the ataxia and a poliomyelitis-like syndrome often seen in cases of echovirus meningomyeloencephalitis. Focal encephalitic lesions, antigen-antibody reactions and live virus were found at numerous levels of the CNS in spite of intrathecal and intravenous immunoglobulin therapy. This mode of therapy and the electron microscopic features noted in echovirus infections are discussed.

Adult↗

Effect of L-cysteine on the activity of penicillin antibiotics against Clostridium difficile.

We observed elevated MICs of penicillin antibiotics while performing agar dilution susceptibility testing of strains of Clostridium difficile on supplemented brain heart infusion agar, an effect which was completely eliminated by the exclusion of L-cysteine from the medium. L-Cysteine antagonizes the activity of penicillins against C. difficile, most likely by direct inactivation of the antibiotic.

Cephalosporins↗

Outbreak of Salmonella typhimurium gastroenteritis due to an imported strain resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole in a nursery.

An outbreak caused by a highly resistant strain of Salmonella typhimurium occurred in a nursery at a university medical center. The outbreak strain, which was resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole, was apparently imported from the Far East by a Cambodian refugee. The five patients involved had severe underlying diseases, and bacteremia and meningitis developed in one of these patients. The only reservoir identified was the gastrointestinal tracts of the infected patients, and infection was probably transmitted by the contaminated hands of hospital personnel. The outbreak was rapidly brought under control by isolating cases outside of the nursery and by instituting enteric precautions for infants who remained in the nursery. When compared by disk diffusion susceptibility tests with 353 strains of S. typhimurium tested at the Centers for Disease Control, the imported strain had a unique antibiogram. Bacteriophage typing of the strains revealed that all were untypable; this, in itself, was a good marker, because only 5 to 10% of S. typhimurium isolates in this country have this property. Agarose gel electrophoresis of isolates from the five patients revealed an identical plasmid banding pattern consisting of three large and three small plasmids. Highly resistant strains of S. typhimurium imported from the Far East may spread rapidly when introduced into a hospital nursery. Prompt institution of control measures may limit the outbreak and prevent systemic infections for which there are few effective therapeutic agents.

Ampicillin↗

Retrospective analysis of plasmid patterns in a study of burn unit outbreaks of infection due to Enterobacter cloacae.

To evaluate the usefulness of plasmid pattern analysis as an epidemiologic tool and to determine the mechanism of resistance to silver sulfadiazine and mafenide acetate, silver sulfadiazine-resistant, mafenide acetate-resistant Enterobacter cloacae isolates from a 1976 outbreak of infections in a burn unit (group I) were analyzed retrospectively. These strains were compared with various E cloacae isolates (groups II-V), including E cloacae isolates from a more recent (1982) burn unit outbreak (group V). Agarose gel electrophoresis (AGE) of DNA isolated from "epidemic" strains of E cloacae revealed a uniform pattern of four plasmid DNA bands, ranging in molecular size from 66 to 2 megadaltons. No such plasmid pattern was seen in silver sulfadiazine-, mafenide acetate-susceptible isolates of E cloacae in groups II, III, and V. Analysis of non-E cloacae coisolates suggested that silver sulfadiazine resistance was associated with the 55-megadalton plasmid. Plasmid pattern analysis easily separated "epidemic" E cloacae isolated in 1976 from those isolated in 1982.

Burns↗

Aspergillus fumigatus endocarditis on a normal heart valve.

We have described an elderly man with no known underlying predisposing systemic or valvular disease who had mitral valve infection and endophthalmitis due to Aspergillus fumigatus. Two-dimensional echocardiography was valuable in detecting fungal vegetations.

Aged↗