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Biomedical subjects

C A Spiegel

Publications and source records attributed to C A Spiegel.

At least 19 recordsLinked to original sources
PubMed1999

Detection of a streptomycin/spectinomycin adenylyltransferase gene (aadA) in Enterococcus faecalis.

Genes encoding streptomycin/spectinomycin adenylyltransferases [ANT(3")(9)] have been reported to exist in gram-negative organisms and Staphylococcus aureus. During a study of high-level aminoglycoside resistance in enterococci, we encountered an isolate of Enterococcus faecalis that was streptomycin resistant but did not appear to contain the 6'-adenylyltransferase gene (aadE) when examined by PCR with specific primers. Phosphocellulose paper binding assays indicated the presence of an ANT(3")(9) enzyme. Streptomycin and spectinomycin MICs of 4,000 and 8,000 microg/ml, respectively, were observed for the isolate. PCR primers corresponding to a highly conserved region of the aadA gene were used to amplify a specific 284-bp product. The product hybridized with a digoxigenin-labeled PCR product from E. coli C600(pHP45Omega) known to contain the aadA gene. The aadA gene was transferred via filter matings from the E. faecalis donor to E. faecalis JH2-2. PCR primers designed for analysis of integrons were used to amplify a 1-kb product containing the aadA gene, which was cloned into the vector pCRII and transformed into Escherichia coli DH5-alpha competent cells. D-Rhodamine dye terminator cycle sequencing was used to determine the gene sequence, which was compared to previously reported sequences of aadA genes. We found the aadA gene in E. faecalis to be identical to the aadA genes reported by Sundstr om et al. for E. coli plasmid R6-5 (L. Sundström, P. Râdström, G. Swedberg, and O. Sköld, Mol. Gen. Genet. 213:191-201, 1988), by Fling et al. for the aadA within transposon Tn7 (M. E. Fling, J. Kopf, and C. Richards, Nucleic Acids Res. 13:7095-7106, 1985), and by Hollingshead and Vapnek for E. coli R538-1 (S. Hollingshead and D. Vapnek, Plasmid 13:17-30, 1985). Previous reports of the presence of the aadA gene in enterococci appear to be erroneous and probably describe an aadE gene, since the isolates were reported to be susceptible to spectinomycin.

Amino Acid Sequence↗
PubMed1998

Use of molecular and reference susceptibility testing methods in a multicenter evaluation of MicroScan dried overnight gram-positive MIC panels for detection of vancomycin and high-level aminoglycoside resistances in enterococci.

Modified MicroScan gram-positive MIC no. 8 panels (PM-8) were analyzed for their improved ability to detect vancomycin resistance (VR) and high-level aminoglycoside resistance (HLAR) in enterococci. A validation study design that utilized selected challenge strains, recent clinical isolates, and reproducibility experiments in a multicenter format was selected. Three independent medical centers compared the commercial panels to reference broth microdilution panels (RBM) and Synergy Quad Agar (QA). Resistance was verified by demonstration of VR and HLAR genes by PCR tests. The study was conducted in three phases. (i) In the challenge phase (CP), two well-characterized sets of enterococci were obtained from the Centers for Disease Control and Prevention; one set contained 50 isolates for VR testing and one contained 48 isolates for HLAR testing. In addition, a set of 47 well-characterized isolates representing diverse geographic areas, obtained from earlier national surveillance studies, was tested at the University of Iowa College of Medicine (UICM). (ii) In the efficacy phase (EP), each laboratory tested 50 recent, unique clinical isolates by all methods. (iii) In the reproducibility Phase (RP), each laboratory tested the same 10 strains by all methods in triplicate on three separate days. All isolates from the EP were sent to the UICM for molecular characterization of vanA, -B, -C1, -C2-3, and HLAR genes. In the CP, the ranking of test methods by error rates (in parentheses; very major and major errors combined, versus PCR results) were as follows: for high-level streptomycin resistance (HLSR), QA (12.0%) > PM-8 (5.2%) > RBM (1.6%); for high-level gentamicin resistance (HLGR), RBM (3.7%) > PM-8 (3.1%) > QA (2.6%); and for VR, RBM = QA (3.0%) > PM-8 (1.2%). In the EP, agreement between all methods and the reference PCR result was 98.0% for HLSR, 99.3% for HLGR, and 98. 6% for VR. In the RP, the percentages of results +/- 1 log2 dilution of the all-participant mode were as follows: for VR, 100% (PM-8), 98.9% (QA), and 90.0% (RBM); for HLSR, 99.6% (RBM), 98.5% (PM-8), and 82.2% (QA); and for HLGR, 99.6% (RBM), 99.3% (PM-8), and 98.1% (QA). The ability of the PM-8 to detect VR and HLAR in enterococci was comparable to those for reference susceptibility and molecular PCR methods and was considered acceptable for routine clinical laboratory use.

Anti-Bacterial Agents↗
PubMed1997

Identification of methicillin-resistant staphylococci by multiplex polymerase chain reaction assay.

A multiplex polymerase chain reaction (PCR) assay using oligonucleotide primers to detect mecA and 16S ribosomal RNA gene was developed to aid in identification of methicillin-resistant staphylococci. Validation included 99 isolates of staphylococcus grouped into one of five categories: methicillin-susceptible coagulase-negative staphylococcus (MSCNS), methicillin-resistant coagulase-negative staphylococcus (MRCNS), methicillin-susceptible Staphylococcus aureus (MSSA), high beta-lactamase producing S aureus (HiBSA), and methicillin-resistant S aureus (MRSA). mecA was detected in MRSA (21/21), and in MRCNS (20/20), but not in MSSA (0/20). mecA was occasionally detected in HiBSA (1/19) and MSCNS (3/19). This multiplex PCR assay was also used to test 30 clinical isolates of coagulase-negative staphylococci with discrepancies between results of in vitro tests for susceptibility to oxacillin and was found to be valuable when a more definitive determination of intrinsic methicillin-resistance was desired.

DNA, Bacterial↗
PubMed1992

Nosocomial sepsis due to Serratia odorifera biovar 1.

Serratia odorifera biovar 1 has been infrequently isolated from humans, and infection caused by this organism rarely has been documented. We report what is, to our knowledge, the first case of nosocomial sepsis due to S. odorifera biovar 1 and review the literature for which English-language abstracts were available on this organism. We also discuss the biochemical characteristics and the antimicrobial susceptibility pattern of this organism.

Aged↗
PubMed1991

Bacteremia caused by hemolytic, high-level gentamicin-resistant Enterococcus faecalis.

Between 1 January 1984 and 31 December 1987, 206 enterococcal blood isolates at the University of Wisconsin Hospital and Clinics were analyzed for high-level aminoglycoside resistance (hereafter high-level aminoglycoside resistance is simply referred to as "resistance") and hemolysin production. Of 190 Enterococcus faecalis isolates, 68 (35.8%) were resistant to gentamicin. Of these 68 strains, 67 (98.5%) contained a gene coding for the bifunctional aminoglycoside-modifying 6'-aminoglycoside acetyltransferase-2"-aminoglycoside phosphotransferase [AAC(6')-APH(2")] enzyme. Of 190 isolates, 85 (44.7%) were hemolytic and contained a gene coding for component A of the enterococcal hemolysin. Sixty-two of 68 (91.2%) gentamicin-resistant isolates but only 23 of 122 (18.8%) gentamicin-susceptible isolates were hemolytic (P less than 0.001). Twelve of the hemolytic, gentamicin-resistant E. faecalis blood isolates, but only 2 of 9 nonhemolytic or gentamicin-susceptible isolates, had identical chromosomal DNA restriction endonuclease digestion patterns, suggesting a common derivation for these strains. A historical cohort study from 1 July 1985 to 31 March 1987 identified by regression analysis postsurgical intensive care unit status (odds ratio [OR], 5.0; 95% confidence interval [CI], 1.1 to 22.8) and prior treatment with an expanded- or broad-spectrum cephalosporin (OR, 3.0; 95% CI, 0.9 to 10.1) as risk factors for gentamicin-resistant E. faecalis bacteremia. Patients with hemolytic, gentamicin-resistant E. faecalis bacteremia had a fivefold-increased risk for death within 3 weeks of their bacteremia compared with patients with nonhemolytic, gentamicin-susceptible strains (95% CI, 1.0 to 25.4).

Bacteremia↗
PubMed1991

Bacterial vaginosis.

Bacterial vaginosis (BV) is the most common of the vaginitides affecting women of reproductive age. It appears to be due to an alteration in the vaginal ecology by which Lactobacillus spp., the predominant organisms in the healthy vagina, are replaced by a mixed flora including Prevotella bivia, Prevotella disiens, Porphyromonas spp., Mobiluncus spp., and Peptostreptococcus spp. All of these organisms except Mobiluncus spp. are also members of the endogenous vaginal flora. While evidence from treatment trials does not support the notion that BV is sexually transmitted, recent studies have shown an increased risk associated with multiple sexual partners. It has also been suggested that the pathogenesis of BV may be similar to that of urinary tract infections, with the rectum serving as a reservoir for some BV-associated flora. The organisms associated with BV have also been recognized as agents of female upper genital tract infection, including pelvic inflammatory disease, and the syndrome BV has been associated with adverse outcome of pregnancy, including premature rupture of membranes, chorioamnionitis, and fetal loss; postpartum endometritis; cuff cellulitis; and urinary tract infections. The mechanisms by which the BV-associated flora causes the signs of BV are not well understood, but a role for H2O2-producing Lactobacillus spp. in protecting against colonization by catalase-negative anaerobic bacteria has been recognized. These and other aspects of BV are reviewed.

Female↗
PubMed1990

Quality control criteria for testing the susceptibility of anaerobic bacteria to meropenem.

Reference values for quality control of in vitro susceptibility tests with meropenem against anaerobic bacteria were determined in a multilaboratory study by the approved National Committee for Clinical Laboratory Standards agar dilution method for the four quality control strains. The study protocol also included the evaluation of microdilution testing, medium additives, and multiple lots of media. The recommended MIC control ranges for three of the control organisms are as follows: Bacteroides fragilis ATCC 25285, 0.06 to 0.125 micrograms/ml; Bacteroides thetaiotaomicron ATCC 29741, 0.125 to 0.5 micrograms/ml; and Eubacterium lentum ATCC 43055, 0.125 to 0.5 micrograms/ml. The modal MIC for Clostridium perfringens ATCC 13124 was at or below the lowest concentration of meropenem tested, and no values are recommended.

Bacteria, Anaerobic↗
PubMed1989

Endocarditis due to streptomycin-susceptible Enterococcus faecalis with high-level gentamicin resistance.

A case of community-acquired endocarditis caused by Enterococcus (Streptococcus) faecalis with high-level resistance to gentamicin sulfate but not to streptomycin sulfate is described. Killing curves performed using achievable serum levels showed synergistic killing when streptomycin but not gentamicin, tobramycin, or amikacin was combined with penicillin G sodium or vancomycin hydrochloride. Combination therapy with vancomycin and streptomycin resulted in cure. Serum bactericidal levels indicated activity of the synergistic, as well as a nonsynergistic (vancomycin plus gentamicin), combination. Routine screening of blood isolates for high-level resistance to streptomycin and gentamicin can provide guidance for selection of therapeutic combinations in serious enterococcal infections, including endocarditis.

Aged↗
PubMed1989

Vaginitis/vaginosis.

Vaginitis/vaginosis is an extremely common medical problem. Most cases are caused by yeast (predominantly Candida albicans), the protozoan Trichomonas vaginalis, or a specific mixture of bacteria (bacterial vaginosis). The prevalence of each of these varies with the patient population. The clinical signs used in differentiating among these and the associated bacterial flora are shown in Table 3. Because vaginitis/vaginosis cannot be adequately diagnosed solely on the basis of symptoms or physical examination, some laboratory methods are required. Yeast vaginitis is diagnosed by microscopic detection of budding yeast or pseudohyphae in vaginal secretions. The most sensitive method for detection of Trichomonas vaginalis is culture, but microscopic methods are more commonly used. Wet-mount examination for motile trichomonads is the least sensitive microscopic method. The sensitivity is increased when fluorescent monoclonal antibodies are used. Bacterial vaginosis may be diagnosed in the clinic by detecting three or more of the following on examination: (1) homogeneous adherent discharge, (2) vaginal fluid pH greater than 4.5, (3) amine odor, and (4) clue cells. A diagnosis may also be made by detecting the replacement of lactobacilli by a mixed presumably anaerobic flora. This is accomplished by examining a Gram stain of vaginal fluid. It is not uncommon for a woman to have more than one microbial source for her vaginal signs and symptoms. A vaginal examination should include appropriate tests for detection of all three of these agents.

Bacterial Infections↗
PubMed1988

The development of a third generation system for entering microbiology data into a clinical laboratory information system.

Increased demands on technologists' time and the desire to have electronic storage of patient information have led to numerous computer-based efforts to manage microbiology data. Our approach to the design of a new microbiology subsystem has been to maximize the functionality without requiring unusual input devices. DEC VT100-compatible terminals are used for data entry and display. Data are displayed taking advantage of such features of these terminals as reverse video, highlighting, and scroll windowing. Numerous single-key instructions for invoking functions and changing cursor positions have been implemented to minimize keystrokes and to anticipate the entry sequences of the technologists. A program that allows the quick location and display of specimens and results is also included in the package.

Clinical Laboratory Information Systems↗
PubMed1988

Laboratory detection of high-level aminoglycoside-aminocyclitol resistance in Enterococcus spp.

Methods for detection of high-level resistance to aminoglycoside-aminocyclitol antibiotics were evaluated using 104 blood isolates of enterococci (97 Enterococcus faecalis and 7 Enterococcus faecium). Kanamycin was used to predict resistance to amikacin. Discrepancies between methods were resolved by time-kill studies. Four methods (MicroScan, macrotube, microtiter, and disk diffusion) for detecting resistance to gentamicin and streptomycin were compared, using 51 consecutive strains. There were 13 gentamicin-resistant strains, all of which were detected by macrotube, microtiter, and disk diffusion. MicroScan detected 2 (15%) of the 13. Of the 18 streptomycin-resistant strains, 17 (93%) were detected by disk diffusion, 16 (89%) by microtiter, 9 (50%) by macrotube, and 6 (33%) by MicroScan. An additional 53 consecutive strains were examined only by disk diffusion and microtiter for resistance to gentamicin, streptomycin, and kanamycin. The entire population of 104 strains contained 35 gentamicin-, 22 streptomycin-, and 54 kanamycin-resistant enterococcal isolates. All 35 gentamicin-resistant strains were detected by both methods. Of the 22 streptomycin-resistant strains, 1 was detected only by microtiter, 2 only by disk diffusion, and 19 by both methods. Of the 54 kanamycin-resistant strains, 1 was detected only by microtiter, 2 only by disk diffusion, and 51 by both methods. One additional strain which was resistant only by disk diffusion was susceptible to amikacin plus penicillin by time-kill studies. Disk diffusion is a suitable method for detection of high-level aminoglycoside-aminocyclitol resistance in E. faecalis and is well suited for sporadic testing. Additional data are necessary to determine the suitability of these tests for E. faecium.

Anti-Bacterial Agents↗
PubMed1987

New developments in the etiology and pathogenesis of bacterial vaginosis.

Bacterial vaginosis is unlike the "classic" sexually transmitted diseases. Unlike cervical infection with Chlamydia or salpingitis caused by N. gonorrhoeae, no single etiologic agent has been identified, and the organisms which are associated with infection have all been found as members of endogenous vaginal flora, with the possible exception of Mobiluncus species. If, as we suspect, BV is due to interactions among various organisms found in the vagina during vaginal health, we must determine what changes in the microbial or chemical ecology determine the development of BV. If, for instance, BV is simply due to an inversion in the concentrations of various organisms such that the anaerobes which are usually present in low numbers become predominant and the lactobacilli which usually predominate become few in number, we must determine which causes what. That is, does some organism or environmental change allow the anaerobes to overgrow and thereby inhibit the lactobacilli, or does some change inhibit the lactobacilli, thereby, allowing the other flora to overgrow? Answers to questions such as these await further research.

Bacterial Infections↗
PubMed1987

Susceptibility of Mobiluncus species to 23 antimicrobial agents and 15 other compounds.

The susceptibility of 12 strains of Mobiluncus curtisii and 10 strains of M. mulieris to 23 antimicrobial agents and 15 other compounds was determined. All strains were susceptible to chloramphenicol, clindamycin, rifampin, tobramycin, vancomycin, virginiamycin, and all beta-lactam antibiotics tested, including imipenem. One strain of M. mulieris was resistant to erythromycin and josamycin. All were resistant to colistin, cycloserine, nalidixic acid, and neomycin. Tetracycline had variable activity. All M. curtisii strains were resistant to metronidazole and its hydroxy metabolite. Of 10 M. mulieris strains, 5 were resistant to metronidazole and 2 were resistant to its hydroxy metabolite. All 12 M. curtisii and 1 of 10 M. mulieris strains were resistant to tinidazole. M. curtisii and M. mulieris produced two mutually exclusive clusters of MICs when tested against ampicillin, cefoxitin, cephalothin, moxalactam, alizarin red, Evans blue, and sodium fluoride. Gardnerella vaginalis was more susceptible to Nile blue A than was either M. curtisii or M. mulieris. Clindamycin and imipenem may be useful agents in the therapy of metronidazole-resistant bacterial vaginosis. Metronidazole, tinidazole, and Nile blue A may be of value in the development of a selective agar for Mobiluncus species.

Anti-Bacterial Agents↗
PubMed1985

Response to immunization after partial and total splenectomy.

Survival after infection from Streptococcus pneumoniae in both animals and man is influenced by the amount of splenic tissue. We investigated the effect of differences in splenic weight upon the antibody response to immunization and the effect of immunization upon survival after pneumococcal challenge. Young Sprague-Dawley rats had either sham operation, hemisplenectomy, splenectomy with splenic autotransplantation, or total splenectomy. Nine weeks later, rats were immunized with a heat- and formalin-killed type-specific pneumococcal vaccine. Antibody response measured by radioimmunoassay was similar in all operative groups and was significantly higher than in nonimmune rats (P less than 0.01). Splenic weight was less after hemisplenectomy or autotransplantation than in sham-operated animals (P less than 0.01). Immunization improved survival after live pneumococcal challenge in rats that had autotransplantation and total splenectomy (P less than 0.001). Our results demonstrate that splenic weight does not affect the antibody response to pneumococcal immunization in rats. Immunization improves survival after bacterial challenge in susceptible animals and minimizes the detrimental effect of reduction in splenic mass.

Animals↗
PubMed1985

Treatment of intra-abdominal infections is appropriate with single-agent or combination antibiotic therapy.

In a prospective, randomized, single-blind trial, we studied 112 adults with intra-abdominal infections and compared antibiotic therapy with cefoxitin plus placebo to therapy with tobramycin plus clindamycin. Seventy-five percent of patients receiving tobramycin-clindamycin and 71% of those receiving cefoxitin-placebo had either shock, bacteremia, malnutrition, alcoholism, rapidly or ultimately fatal underlying disease, infection originating from the distal small bowel or colon, or had had failed therapy before treatment ("high-risk" group). One third of the patients in both groups grew bacteria in the initial culture resistant to the antibiotic regimen used. Ten patients receiving cefoxitin-placebo (17%) and 11 receiving tobramycin-clindamycin (21%) had recurrence of infection or died of infection (clinical failures). Nineteen failures occurred in high-risk patients (p less than 0.05) and 17 were in patients that had antibiotic-resistant bacteria in the initial culture (p less than 0.01). Adverse effects were rare and remitted after antibiotics were stopped. Our results suggest that both cefoxitin and tobramycin-clindamycin are appropriate antibiotic regimens to treat intra-abdominal infections. Clinical failure is more common in high-risk patients and when antibiotic-resistant organisms are isolated from initial cultures.

Adult↗
PubMed1984

Gas-liquid chromatography for rapid diagnosis of intra-abdominal infection.

We assessed the usefulness of gas-liquid chromatography in detecting fecal anaerobes in patients with suspected intra-abdominal infection related to the lower gastrointestinal tract. Twenty-five (89%) of 28 cultures with and five (26%) of 19 cultures without anaerobic isolates were positive for succinate. Data analysis showed that Bacteroides but not Enterobacteriaceae organisms were responsible for succinate production. Volatile acids other than acetate (VAs) were present in 16 (57%) of 28 culture-positive and one (7%) of 14 culture-negative specimens. Sixteen (94%) of 17 VA-positive and seven (28%) of 25 VA-negative specimens had anaerobic isolates shown by culture. The presence of certain VAs was associated with the recovery of specific groups of anaerobic bacteria. The presence of succinate or VA in intra-abdominal fluid provides a specific, useful method for the rapid detection of fecal anaerobes in patients with intra-abdominal infections.

Abdomen↗