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Biomedical subjects

D M Shlaes

Publications and source records attributed to D M Shlaes.

At least 91 records · Page 5Linked to original sources
PubMed1986

Comparative activities of the beta-lactamase inhibitors YTR 830, clavulanate, and sulbactam combined with ampicillin and broad-spectrum penicillins against defined beta-lactamase-producing aerobic gram-negative bacilli.

The in vitro synergistic activities of the beta-lactamase inhibitors YTR 830, clavulanate, and sulbactam, combined with ampicillin, ticarcillin, mezlocillin, azlocillin, piperacillin, and apalcillin, were determined against 34 strains of members of the Enterobacteriaceae family, Pseudomonas aeruginosa, Aeromonas hydrophila, and Haemophilus influenzae with characterized plasmid or chromosomal beta-lactamases or both. Strains were tested against fixed concentrations of beta-lactamase inhibitors (8 micrograms/ml) combined with doubling dilutions of beta-lactams. Synergy was defined as a fourfold or greater decrease in the MIC of the beta-lactam. Against Enterobacteriaceae producing Richmond and Sykes class III and V plasmid-mediated beta-lactamases, synergy was obtained against most strains with YTR 830- and clavulanate-beta-lactam combinations, with sulbactam being less effective. Against Enterobacteriaceae producing class I chromosomal beta-lactamases, combinations containing YTR 830 or sulbactam were more synergistic than combinations containing clavulanate. Against strains producing class V PSE enzymes, all three inhibitors were synergistic with piperacillin and apalcillin against strains producing PSE-1, -3, and -4 enzymes, while the PSE-2-producing strain was resistant to all inhibitors. YTR 830-beta-lactam combinations were also synergistic against strains producing the novel beta-lactamases OHIO-1, TLE-1, AER-1, and ROB-1. Overall, YTR 830 with piperacillin or apalcillin was the most effective combination.

Ampicillin↗
PubMed1986

Novel plasmid-mediated beta-lactamase in members of the family Enterobacteriaceae from Ohio.

Epidemiologic studies of plasmid-mediated resistance at the Cleveland Veterans Administration Medical Center revealed that related plasmids had disseminated among members of the family Enterobacteriaceae. We studied the beta-lactamases encoded by these plasmids in Escherichia coli C600 transformants or transconjugants. Substrate and inhibition profiles of the enzymes determined by two of these plasmids suggested an activity resembling TEM-1; however, isoelectric focusing revealed a pI of 7.0. These two plasmids were originally found in a Serratia marcescens (pDS076) and an Enterobacter cloacae (pDS075) strain isolated from the same sink in the medical intensive care unit and later, in an Enterobacter cloacae (pDS142 identical to pDS076) isolate colonizing a patient in the same unit. The plasmids also carried the aminoglycoside resistance determinant, 2"-aminoglycoside nucleotidyl transferase. A 2-kilobase AvaI restriction endonuclease digestion fragment of pSD075 known to carry the beta-lactamase determinant was used as a molecular probe. This probe did not recognize sequences of any plasmid-mediated beta-lactamase tested including the recently described determinants ROB-1, TLE-1, and OXA-4-7. A TEM-1 probe derived from the 0.7-kilobase PstI-EcoRI fragment of pBR322 failed to recognize the new beta-lactamase gene. Four additional Enterobacter cloacae and two Enterobacter aerogenes strains isolated in Columbus, Ohio, have been shown to produce a pI 7.0 beta-lactamase and to carry plasmids recognized by the 2-kilobase probe. These data suggest dissemination of a novel plasmid-mediated beta-lactamase among members of the family Enterobacteriaceae in Ohio and demonstrate the development and utility of a molecular probe for the new determinant. We suggest that the novel beta-lactamase be named OHIO-1.

DNA, Bacterial↗
PubMed1985

Wangiella dermatitidis endocarditis in an intravenous drug user.

Wangiella dermatitidis is an infrequently encountered dematiacious fungus that usually causes localized infections of the skin and subcutaneous tissues. This report presents the first well-documented case of natural valve infection caused by this organism as it occurred in intravenous drug abuser. His course has been complicated by relapsing infection of two aortic prostheses and dissemination to the vertebral spine. Treatment with a combination of amphotericin B, rifampin, and ketoconazole has arrested the progression of his infection. The microbiologic features and existing clinical information regarding this fungus are reviewed and in vitro susceptibility data for the present isolate are presented.

Adult↗
PubMed1985

Infections due to Lancefield group G streptococci.

The group G streptococcus has surfaced in the past 10 to 15 years as an important opportunistic and nosocomial pathogen. Although more precise organism recognition accounts for a portion of these cases, there can be little doubt that the group G streptococcus has become a more prevalent pathogen. Commercial kits, utilizing staphylococcal coagglutination or latex agglutination, are now available, affording all clinical laboratories the opportunity to identify this organism easily. Published reviews encompassing the experiences of a single institution or even several institutions affiliated with a single medical center, particularly as they were influenced by referral patterns, did not reflect the broad scope of infections that we discovered by extending our survey into the community, beyond the medical center complex and its immediate affiliated hospitals. Although malignancy is the single most obvious background factor, alcoholism and diabetes are also important host determinants of infection. Skin and soft-tissue infections (and surface sources of infection) are equally important among patients with or without the element of malignancy. Polymicrobial infection, including polymicrobial bacteremia, is an important feature, with S. aureus infections accounting for most of these cases, relating to the skin and soft tissue sources of infections so commonly seen. We saw a panorama of problems including endocarditis, septic arthritis, pleuropulmonary infections, bone and joint infections, puerperal sepsis and neonatal infection, peritonitis and ophthalmitis; we also saw a significant number of patients with bacteremia and no apparent primary source of infection. Response to antibiotic therapy was dictated by the nature of the underlying diseases, and individuals without a background of malignant disease did well, particularly those with skin and soft-tissue infections. While the literature suggests that patients with endocarditis and septic arthritis due to this organism respond poorly to antibiotic therapy, implying that such failures relate to in vitro antibiotic phenomena, we preferred to examine the problem from the viewpoint of the host(s) involved. Subacute endocarditis and acute endocarditis due to the group G streptococcus may be clinically separable, and thus require separate therapeutic approaches. In patients with septic arthritis, prosthetic devices, prior joint disease and immunosuppressive diseases and therapy often adversely influence the response to antibiotic therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Abortion, Septic↗
PubMed1984

Infection caused by vancomycin-resistant Streptococcus sanguis II.

A patient with bacteremia caused by vancomycin-resistant Streptococcus sanguis II is presented. This rare occurrence suggests that vancomycin may not be a completely reliable antibiotic in the treatment of infections due to viridans species of the genus Streptococcus. Gram-positive isolates from blood and otherwise sterile body fluids should be tested for susceptibility to vancomycin.

Anti-Bacterial Agents↗
PubMed1984

Comparison of latex agglutination and immunofluorescence for direct Lancefield grouping of streptococci from blood cultures.

Simulated positive blood cultures with 84 known stock strains of streptococci were used to comparatively evaluate the direct identification of these organisms by fluorescein-tagged antibody staining (immunofluorescence [IF]) and latex agglutination (LA). IF was not evaluated for Lancefield group D strains (a total of 81 strains tested) and had 89% sensitivity and 91% specificity. IF was least sensitive for the identification of Lancefield group F, in which three of seven strains showed no fluorescence with the group F reagent. Since LA was more convenient and revealed comparable sensitivities and specificities on 84 simulated cultures, we tested this procedure using an additional 29 fresh positive clinical blood cultures, for a total of 113 cultures tested by this technique. Of 11 Streptococcus pneumoniae strains, 9 reacted with the LA group C reagent, a problem not observed with IF. However, all these strains were identified by a rapid modified bile solubility test. Of the 12 Streptococcus faecalis strains, 4 were falsely negative with the group D reagent, but all were correctly identified by a rapid litmus milk reduction test. Of 12 group A strains, 1 was not detected. Of all 113 strains tested by LA, eliminating S. faecalis and S. pneumoniae, the sensitivity and specificity were 97 and 98%, respectively. LA was simple and reliable in the rapid identification of streptococci from blood cultures and appeared to be preferable to IF. When LA is used, the group D reagent should not be used, and all samples reacting with the group C reagent should be tested by a modified rapid bile solubility test to exclude S. pneumoniae.

Blood↗
PubMed1984

Sputum elastin fibers and the diagnosis of necrotizing pneumonia.

Potassium hydroxide (KOH) preparations for elastin fibers on sputum obtained from 80 patients seen over a four-month period at two Cleveland hospitals were performed. The results were compared with roentgenographic evidence of necrosis and case diagnosis. Sixty-one patients had neither elastin in sputum nor roentgenographic evidence of cavitation; 11 had positive results using both methods. Two patients had no elastin fibers in sputum but had parenchymal pulmonary cavities on chest x-ray film. Six patients had elastin observed in KOH preparations of sputum, but no cavitation roentgenographically. The presence of elastin in sputum was strongly correlated with roentgenographic evidence of pulmonary necrosis (p = 5.7 X 10(-8]. Including patients seen before, after, and during the prospective study, we have observed a total of nine with positive sputum preparations for elastin and no cavitation on chest x-ray film for whom tissue was available for study. All had pulmonary necrosis histologically. Our observations suggest that the KOH preparation of sputum for elastin fibers may be more sensitive than the chest roentgenogram in the detection of pulmonary necrosis and may be a useful adjunct in the diagnosis of necrotizing disease.

Diagnosis, Differential↗
PubMed1984

Toxic-shock syndrome associated with nasal packing: analogy to tampon-associated illness.

A pure culture of migmatoxin-producing Staphylococcus aureus was isolated from the purulent nasal packing removed from a 13-year-old premenarchal girl with toxic-shock syndrome after rhinoplasty. The similarities between this case and the tampon-associated illness are examined. An increased awareness of these similarities and the identification of predisposing factors may lead to earlier detection and treatment of toxic-shock syndrome.

Adolescent↗
PubMed1983

Combination antimicrobial therapy.

In spite of a large volume of data regarding the in vitro activity of single and combined antimicrobial activity, the clinical relevance of these studies is unclear. Few comparative trials of combined and single antibiotic therapy of human infection have been performed. Synergistic combination therapy has been shown to be beneficial in a few specific circumstances. Antagonistic combinations should be avoided in the treatment of meningitis, endocarditis, and infections of immunocompromised patients. The bactericidal titer of serum or spinal fluid should reflect adequacy of therapy of meningitis, endocarditis, and osteomyelitis, and adjustments can be made accordingly.

Adult↗
PubMed1983

Variability in DNA sequence of closely related nosocomial gentamicin-resistant plasmids.

Endemic gentamicin-resistant plasmids derived from 12 species of gram-negative bacilli were analyzed by restriction-endonuclease digestion. These digests showed wide variations in digest patterns, but one or more common fragments were seen in all plasmids studied. Southern blot analysis using one plasmid as a probe revealed that most but not all of these plasmids shared extensive regions of homology. The variance observed in restriction-digest patterns could be accounted for either by introduction of unrelated DNA or by intramolecular events. We conclude that variation in restriction-digest patterns of endemic gentamicin-resistant plasmids is insufficient to establish that the plasmids are not closely related. Variation in molecular structure of closely related, endemic gentamicin-resistant plasmids may be more common than has previously been suspected.

Base Sequence↗
PubMed1983

Rapid identification of Staphylococcus aureus and Streptococcus pneumoniae from blood cultures.

Simultaneous application of the lysostaphin sensitivity test for identification of Staphylococcus aureus and the deoxycholate test for the identification of Streptococcus pneumoniae was evaluated for reliability in rapid identification (1 h) of these organisms from blood cultures by using BACTEC 6B and 7C bottles. The procedure was applied to 127 cultures, 74 lysostaphin tests and 53 deoxycholate tests. Lysostaphin-tested organisms included 23 S. aureus, 40 Staphylococcus epidermidis, 1 Listeria sp., 1 Peptococcus sp., 2 Micrococcus sp., 2 diphtheroids, and 5 mixed cultures. Deoxycholate-tested organisms included 14 S. pneumoniae, 32 Streptococcus spp. (not S. pneumoniae), 1 Listeria sp., 1 Peptococcus sp., 2 diphtheroids, and 3 mixed cultures. Analysis of the data revealed positive and negative predictive values of 95.8 and 94%, respectively, for the lysostaphin test and 100 and 97.4%, respectively, for the deoxycholate test. The combined tests provide rapid reliable identification or elimination of S. aureus and S. pneumoniae in blood cultures.

Blood↗
PubMed1983

Infection caused by thymidine-requiring, trimethoprim-resistant bacteria.

We first noted the appearance of thymidine-requiring, gram-negative bacilli in clinical specimens 2 years ago. Since then we have seen 10 patients colonized or infected with these organisms. These strains do not grow on Mueller-Hinton media, growth on MacConkey agar is variable, and growth in API 20E (Analytab Products) and Enterobacteriaceae-Plus Cards (AutoMicrobic system; Vitek Systems Inc.) is inadequate for reliable identifications. Thymidine-requiring organisms are routinely resistant to sulfonamides and trimethoprim. Infection or colonization is associated with previous sulfamethoxazole-trimethoprim therapy in most cases. Of 10 patients, 1 had septicemia of urinary tract origin, 5 had urinary tract colonization or infection, 2 had wound colonization, and two had colonization of respiratory secretions. Thymidine-requiring, gram-negative bacilli can be pathogens and present potential problems in diagnosis, identification, and susceptibility testing.

Adult↗
PubMed1983

Epidemiology of gentamicin-resistant, gram-negative bacillary colonization in a spinal cord injury unit.

A prospective epidemiological survey of a spinal cord injury unit for gentamicin-resistant, gram-negative bacilli was undertaken. The initial survey of the unit suggested a low level of cross-infection involving Pseudomonas aeruginosa and Providencia stuartii. However, a longitudinal study of new admissions revealed that only 13 of 52 nosocomial acquisitions could be considered to be due to cross colonization. Comparison of data on antibiotic use did not suggest selective pressure for resistant endogenous flora. Nosocomial acquisition was directly related to the length of the hospital stay. Antibiotic susceptibility testing of gentamicin-resistant, gram-negative bacilli showed only minor differences between nosocomial isolates and those present during the initial survey. Of the usual antimicrobial agents, amikacin, carbenicillin, and cefoxitin were the most active against all organisms, with the exception of Serratia spp. Of the new beta-lactams, ceftazidime and imipemide (N-formimidoyl thienamycin) were most active.

Acinetobacter↗
PubMed1983

Endemic gentamicin resistance R factors on a spinal cord injury unit.

Cleared lysates of gentamicin-resistant, gram-negative bacilli obtained during a prevalence survey and a subsequent prospective study on a spinal cord injury unit were analyzed. Of 105 strains obtained during the epidemiological study, 62 were analyzed for plasmid content. None of the 14 Acinetobacter strains carried plasmids. Of 20 strains from the initial prevalence survey, 9 carried a 36- or (in two cases) a 27-megadalton plasmid. Eight of the nine were Providencia strains; none were Pseudomonas strains. Of 28 nosocomial isolates obtained during the prospective survey, 22 carried plasmids of similar molecular weight (P less than 0.025, compared with the prevalence survey), including 20 of 22 isolates of members of the family Enterobacteriaceae and 2 of 6 Pseudomonas aeruginosa isolates. Conjugation, curing, and transformation indicate that these plasmids carry gentamicin, tobramycin, kanamycin, ampicillin, carbenicillin, cephalothin, and, variably, chloramphenicol resistance. Restriction endonuclease digestion of purified plasmid DNA suggests that the plasmids from multiple species of the family Enterobacteriaceae contain common sequences, whereas those from Pseudomonas spp. do not. This study suggests that an endemic conjugal 36-megadalton gentamicin resistance R factor exists in many nosocomial species of the family Enterobacteriaceae.

Acinetobacter↗
PubMed1983

EF-4 bacteremia in a patient with hepatic carcinoid.

An organism similar to EF-4, a member of the unclassified group of unusual gram-negative bacilli of Elizabeth O. King, was isolated from the blood of a 65-year-old female with previously diagnosed carcinoid of the liver. We believe this to be the first report of systemic infection with this organism.

Aged↗
PubMed1983

Elastin fibers in the sputum of patients with necrotizing pneumonia.

We have observed five patients for whom the presence of fibers of elastin in potassium hydroxide (KOH) preparations of sputum represented the first evidence of necrotizing pulmonary disease. In four cases, the discovery of elastin fibers in sputum provided additional evidence supporting initiation or modification of antibiotic therapy. Necrotizing disease was confirmed in all cases by autopsy or by the development of cavitation on chest x-ray film. Cytochemical staining, electron microscopy, and elastase digestion all suggest that the refractile fibers seen on KOH wet mount of sputum are elastin. The test, first described in 1846, is simple to perform, requires little experience to read, and may be a valuable adjunct to the chest roentgenogram in the diagnosis of pulmonary parenchymal destruction.

Adult↗
PubMed1982

Capnocytophaga bacteremia in the compromised host.

Capnocytophaga, a CO2-requiring gram-negative bacillus, is a recently recognized pathogen in the immunocompromised host. The authors present two cases with granulocytopenia, oral disease and bacteremia with Capnocytophage ochracea. The microbiology of this genus, its clinical association with periodontal disease, granulocytopenia and oral ulceration, and its implications for the compromised host are reviewed.

Adult↗