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Allard R, Dascal A, Camara B, Létourneau J, Valiquette L. Community-acquired Clostridium difficile-associated diarrhea, Montréal, 2005-2006: frequency estimates and their validity. Infect Control Hosp Epidemiol 2011; 32:1032-4. [PMID: 21931255 DOI: 10.1086/661911] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A retrospective search for community-acquired Clostridium difficile-associated diarrhea in 15 hospitals revealed important discrepancies with numbers for the same period reported in real time to the surveillance system. Several of the observed problems could be solved by implementing case-by-case notification with subsequent investigation by local public health, as for other reportable diseases.
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Affiliation(s)
- Robert Allard
- Public Health Department, Montréal Health and Social Services Agency, Montréal, Québec, Canada.
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Quan Y, Brenner BG, Dascal A, Wainberg MA. Highly diversified multiply drug-resistant HIV-1 quasispecies in PBMCs: a case report. Retrovirology 2008; 5:43. [PMID: 18513421 PMCID: PMC2426714 DOI: 10.1186/1742-4690-5-43] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Accepted: 05/30/2008] [Indexed: 12/01/2022] Open
Abstract
Background Although drug resistance is a major challenge in HIV therapy, the effect of drug resistance mutations on HIV evolution in vivo is not well understood. We have now investigated genetic heterogeneity in HIV-1 by performing drug resistance genotyping of the PR-RT regions of viruses derived from plasma and peripheral blood mononuclear cells (PBMCs) of a single patient who had failed multiple regimens of anti-retroviral therapy. Results Patterns of drug resistance mutations showed that the viral populations in PBMCs were more heterogeneous than in plasma. Extensive analysis of HIV from infected PBMCs in this patient showed that high-level diversity existed among 109 cloned PR-RT sequences and that the majority of mutations were related to drug resistance. Moreover, the PBMCs included archival species that reflected the treatment history of the patient while those in plasma were mainly related to the most recent treatment. Some of the proviral clones contained single or multiple mutations in various combinations. Approximately eighteen percent of the proviral clones derived from infected PBMCs were defective, i.e. 5.5% contained single nucleotide deletions (frameshift mutations) and 12.8% encoded in-frame stop codons (nonsense mutations). Amino acid substitutions in PR and the polymerase region of RT occurred in 12–15% of cases but were much less frequent in the RNase H region of RT, which might not have been under drug selection pressure. Conclusion Selective drug pressure can yield multiple drug-resistant quasispecies that include archival and replication-incompetent species in PBMC reservoirs.
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Affiliation(s)
- Yudong Quan
- McGill University AIDS Centre, Lady Davis Institute-Jewish General Hospital, 3755 Cote Ste-Catherine Road, Montreal, Quebec, H3T 1E2, Canada.
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Brukner I, Krajinovic M, Dascal A, Labuda D. A protocol for the in vitro selection of specific oligonucleotide probes for high-resolution DNA typing. Nat Protoc 2007; 2:2807-14. [DOI: 10.1038/nprot.2007.398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nowak T, Patel AM, Dascal A, Haghighat F, Rastan S, Morofsky E, Butler I, Kozinski JA. Implementation of eWAR system in the neutralization of selected chemicals in building ventilation systems. ACTA ACUST UNITED AC 2007. [DOI: 10.2495/safe070531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hubert B, Loo VG, Bourgault AM, Poirier L, Dascal A, Fortin E, Dionne M, Lorange M. A portrait of the geographic dissemination of the Clostridium difficile North American pulsed-field type 1 strain and the epidemiology of C. difficile-associated disease in Québec. Clin Infect Dis 2006; 44:238-44. [PMID: 17173224 DOI: 10.1086/510391] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2006] [Accepted: 09/28/2006] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND An increase in the incidence and severity of Clostridium difficile-associated disease in Québec and the United States has been associated with a hypervirulent strain referred to as North American pulsed-field type 1 (NAP1)/027. METHODS In 2005, a prospective study was conducted in 88 Québec hospitals, and 478 consecutive nosocomial isolates of C. difficile were obtained. The isolates were subjected to pulsed-field gel electrophoresis (PFGE) typing, antimicrobial susceptibility testing, and detection of binary toxin genes and tcdC gene deletion. Data on patient age and occurrence of complications were collected. RESULTS PFGE typing of 478 isolates of C. difficile yielded 61 PFGE profiles. Pulsovars A (57%), B (10%), and B1 (8%) were predominant. The PFGE profile of pulsovar A was identical to that of strain NAP1. It showed 67% relatedness with 15 other PFGE patterns, among which 11 had both binary toxin genes and a partial tcdC deletion but different antibiotic susceptibility profiles. Pulsovars B and B1 were identical to strain NAP2/ribotype 001. In hospitals showing a predominant clonal A or B-B1 PFGE pattern, incidence of C. difficile-associated disease was 2 and 1.3 times higher, respectively, than in hospitals without any predominant clonal PFGE pattern. Severe disease was twice as frequent among patients with strains possessing binary toxin genes and tcdC deletion than among patients with strains lacking these virulence factors. CONCLUSIONS This study helped to quantify the impact of strain NAP1 on the incidence and severity of C. difficile-associated disease in Québec in 2005. The identification of the geographic dissemination of this predominant strain may help to focus regional infection-control efforts.
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Affiliation(s)
- Bruno Hubert
- Institut National de Santé Publique du Québec, Québec, Canada.
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Loo VG, Poirier L, Miller MA, Oughton M, Libman MD, Michaud S, Bourgault AM, Nguyen T, Frenette C, Kelly M, Vibien A, Brassard P, Fenn S, Dewar K, Hudson TJ, Horn R, René P, Monczak Y, Dascal A. A predominantly clonal multi-institutional outbreak of Clostridium difficile-associated diarrhea with high morbidity and mortality. N Engl J Med 2005; 353:2442-9. [PMID: 16322602 DOI: 10.1056/nejmoa051639] [Citation(s) in RCA: 1499] [Impact Index Per Article: 78.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND In March 2003, several hospitals in Quebec, Canada, noted a marked increase in the incidence of Clostridium difficile-associated diarrhea. METHODS In 2004 we conducted a prospective study at 12 Quebec hospitals to determine the incidence of nosocomial C. difficile-associated diarrhea and its complications and a case-control study to identify risk factors for the disease. Isolates of C. difficile were typed by pulsed-field gel electrophoresis and analyzed for binary toxin genes and partial deletions in the toxin A and B repressor gene tcdC. Antimicrobial susceptibility was evaluated in a subgroup of isolates. RESULTS A total of 1703 patients with 1719 episodes of nosocomial C. difficile-associated diarrhea were identified. The incidence was 22.5 per 1000 admissions. The 30-day attributable mortality rate was 6.9 percent. Case patients were more likely than matched controls to have received fluoroquinolones (odds ratio, 3.9; 95 percent confidence interval, 2.3 to 6.6) or cephalosporins (odds ratio, 3.8; 95 percent confidence interval, 2.2 to 6.6). A predominant strain, resistant to fluoroquinolones, was found in 129 of 157 isolates (82.2 percent), and the binary toxin genes and partial deletions in the tcdC gene were present in 132 isolates (84.1 percent). CONCLUSIONS A strain of C. difficile that was resistant to fluoroquinolones and had binary toxin and a partial deletion of the tcdC gene was responsible for this outbreak of C. difficile-associated diarrhea. Exposure to fluoroquinolones or cephalosporins was a risk factor.
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Affiliation(s)
- Vivian G Loo
- Department of Microbiology, McGill University Health Center, Montreal, Que., Canada.
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Zaharatos GJ, Dascal A, Miller MA. Discordant carbapenem susceptibility in Methylobacterium species and its application as a method for phenotypic identification. J Clin Microbiol 2001; 39:2037-8. [PMID: 11388170 PMCID: PMC88082 DOI: 10.1128/jcm.39.5.2037-2038.2001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Brenner B, Wainberg MA, Salomon H, Rouleau D, Dascal A, Spira B, Sekaly RP, Conway B, Routy JP. Resistance to antiretroviral drugs in patients with primary HIV-1 infection. Investigators of the Quebec Primary Infection Study. Int J Antimicrob Agents 2000; 16:429-34. [PMID: 11118853 DOI: 10.1016/s0924-8579(00)00270-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The widespread use of antiretroviral agents (ARVs) and the growing occurrence of HIV strains resistant to these drugs have given rise to serious concerns regarding the transmission of resistant viruses to newly infected persons. Plasma viral RNA from 80 individuals newly infected between 1997 and 1999 was genotyped by automated sequencing to analyze the profile of viruses resistant to nucleoside and non-nucleoside reverse transcriptase inhibitors (NRTIs and NNRTIs) and to protease inhibitors (PIs). The prevalence of mutations that conferred primary resistance to PIs (L10I, D30Y, V82A, L90M) was 15% of the cohort. RT genotypic variants, associated with high-level resistance to ARVs, were observed in 21% of individuals, including NRTI, NNRTI and multidrug (MDR) resistance in 6, 5, and 10% of cases, respectively. The phenotypic susceptibility of viral isolates to ARVs was also assayed and showed transmission of high-level resistance to ZDV, 3TC, and PIs in those individuals with MDR. The transmission of drug-resistant HIV genotypic variants is a serious problem that merits further attention by public health officials, virologists, and clinicians.
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Affiliation(s)
- B Brenner
- McGill University AIDS Centre, Lady Davis Institute-Jewish General Hospital, 3755 Cote Site-Catherine Road, Montreal, Quebec, Canada H3T 1E2
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Miller MA, Dascal A, Portnoy J, Mendelson J. Development of mupirocin resistance among methicillin-resistant Staphylococcus aureus after widespread use of nasal mupirocin ointment. Infect Control Hosp Epidemiol 1996; 17:811-3. [PMID: 8985769 DOI: 10.1086/647242] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
All methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from colonized or infected patients in a 625-bed public teaching hospital during an epidemic, and for 3 years thereafter, underwent susceptibility testing to mupirocin. Mupirocin resistance among MRSA increased markedly over this period (1990, 2.7%; 1991, 8.0%; 1992, 61.5%; 1993, 65%) in association with increased use of mupirocin ointment as an adjunct to infection control measures.
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Affiliation(s)
- M A Miller
- Department of Microbiology, SMBD-Jewish General Hospital, Montreal, Quebec, Canada
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Miller MA, Thibert L, Desjardins F, Siddiqi SH, Dascal A. Growth inhibition of Mycobacterium tuberculosis by polyoxyethylene stearate present in the BACTEC pyrazinamide susceptibility test. J Clin Microbiol 1996; 34:84-6. [PMID: 8748279 PMCID: PMC228736 DOI: 10.1128/jcm.34.1.84-86.1996] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have previously found that approximately 3.5% of 428 clinical isolates of Mycobacterium tuberculosis yield uninterpretable results in the BACTEC pyrazinamide (PZA) susceptibility test system, because of inadequate growth. We tested the hypothesis that polyoxyethylene stearate (POES), the ingredient of the reconstituting fluid for the test, was the cause of this growth inhibition. A total of 15 isolates known for their previously uninterpretable results and 100 randomly chosen clinical isolates were tested in parallel both with and without POES. Repeat testing of the isolates with previously uninterpretable results yielded results in the presence of POES in only seven (47%). In the absence of POES, all gave interpretable results but one such result showed false resistance. For the other 100 clinical isolates, interpretable results were obtained with and without POES, but growth was enhanced in the absence of POES, especially in the PZA-susceptible strains. This was evidenced by a decreased time to attain a growth index of 200 in the control vial (4.9 days without POES versus 5.8 days with POES; P < 0.001) and a higher mean growth index ratio on the day of interpretation of the test (7.4% without POES versus 2.2% with POES; P < 0.001). However, the enhanced growth without POES led to 20 susceptible strains being misinterpreted as either resistant or borderline. We suggest that isolates of M. tuberculosis which yield uninterpretable results in the BACTEC PZA test system should be retested both with and without POES. If interpretable results indicating PZA resistance are obtained only in the absence of POES, the result should be confirmed by a pyrazinamidase assay or by the conventional proportion method. Routine omission of POES from the BACTEC test for all clinical strains is discouraged because of the unacceptably high false-resistance rates.
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Affiliation(s)
- M A Miller
- McGill University, SMBD-Jewish General Hospital, Montreal, Quebec, Canada
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Miller MA, Thibert L, Desjardins F, Siddiqi SH, Dascal A. Testing of susceptibility of Mycobacterium tuberculosis to pyrazinamide: comparison of Bactec method with pyrazinamidase assay. J Clin Microbiol 1995; 33:2468-70. [PMID: 7494049 PMCID: PMC228441 DOI: 10.1128/jcm.33.9.2468-2470.1995] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The susceptibility of 428 clinical isolates of Mycobacterium tuberculosis to pyrazinamide was assessed by the Bactec method and the Wayne pyrazinamidase assay. The correlation between the two tests was 98.2 and 100% for susceptible and resistant strains, respectively. False resistance was seen in four (0.8%) strains with the Bactec test, and false-susceptible results occurred in two (0.5%) pyrazinamidase assays. The Bactec test is rapid and reliable, and the Bactec results correlate well with the pyrazinamidase test results, although some strains did not grow well in the test medium.
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Affiliation(s)
- M A Miller
- McGill University, Montreal, Quebec, Canada
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12
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Abstract
The serogroup/serotypes (SGTs) and antimicrobial susceptibilities to 10 antimicrobial agents of 110 clinical strains of Streptococcus pneumoniae were determined. Strains intermediately resistant or highly resistant to penicillin G (80 of 110) belonged predominantly to SGTs 23 (45.0%), 19 (13.7%), 6 (10.0%), 9 (6.2%), and 14 (3.7%). The MICs of all cephalosporins, tetracycline, trimethoprim-sulfamethoxazole, and chloramphenicol increased along with the MICs of penicillin G. However, erythromycin resistance and clindamycin resistance were observed more frequently among the intermediately penicillin-resistant strains. Multiple resistance was observed for 32 strains, of which 25 were highly resistant to penicillin G and belong to SGT 23F. All strains were susceptible to vancomycin.
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Affiliation(s)
- L P Jetté
- Laboratoire de santé publique du Québec, Sainte-Anne-de-Bellevue, Canada
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Dascal A, Libman M. Reply. Clin Infect Dis 1992. [DOI: 10.1093/clinids/15.1.170-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Tessler M, Dascal A, Gioseffini S, Miller M, Mendelson J. Growth curves of Staphylococcus aureus, Candida albicans, and Moraxella osloensis in propofol and other media. Can J Anaesth 1992; 39:509-11. [PMID: 1534525 DOI: 10.1007/bf03008718] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Propofol, 2,6 diisopropylphenol, in an emulsion formulation (Diprivan), has been associated with postsurgical infections caused by Staphylococcus aureus, Moraxella osloensis and Candida albicans. These organisms were individually inoculated into each of the following media: (1) the emulsion preparation of propofol, (2) Intralipid 10%, (3) pure 2,6 diisopropylphenol, and (4) trypticase soy broth (TSB). The organisms were incubated and subcultured hourly for eight hours at room temperature. Propofol supported the growth of all three organisms, but for S. aureus and M. osloenis, the growth rate was slower in propofol than in TSB (P less than 0.05). There was no difference between the growth rate of any organism in propofol than in Intralipid 10%. The authors conclude that propofol, in the emulsion formulation, supports bacterial growth and, therefore, must be prepared for administration in an aseptic manner. Also, by administering propofol soon after preparation, the risk of introduction of a significant inoculum to the patient will be reduced.
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Affiliation(s)
- M Tessler
- Department of Anaesthesia and Medicine, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec, Canada
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Yechouron A, Dascal A, Stevenson J, Mendelson J. Ability of National Committee for Clinical Laboratory Standards-recommended quality control strains from the American Type Culture Collection to detect errors in disk diffusion susceptibility tests. J Clin Microbiol 1991; 29:2758-62. [PMID: 1757546 PMCID: PMC270428 DOI: 10.1128/jcm.29.12.2758-2762.1991] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The National Committee for Clinical Laboratory Standards (NCCLS) recommends, as a quality control for the disk diffusion susceptibility test, the use of three strains from the American Type Culture Collection: Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922. This study assesses the capacity of these strains to detect errors in the overall method. ATCC strains were tested by comparing testing by the standard NCCLS-recommended procedure (ST) with testing under the following conditions: incubation at 25 degrees C, Mueller-Hinton agar depths of 2 mm (AD2) and 8 mm (AD8), agar pHs of 6.5 and 8, inocula with McFarland standards of 0.25 (0.25M) and 4.0 McFarland (4.0M), direct inoculation without preincubation of inoculum (DI), and a 2-h delay between inoculation and disk application (2HR). The frequency of zone measurements outside the NCCLS-recommended control zone limits were as follows: ST, 0%; AD2, 18%; AD8, 9.6%; pH 6.5, 7.9%; pH 8, 5.3%; 0.25M, 3.5%; 4.0M, 24%; DI, 3.4%; 2HR, 1.8%; 25 degrees C (only E. coli and P. aeruginosa were evaluable), 28%. These results suggest that the quality control strains are only partially effective in detecting single extreme laboratory errors and that careful laboratory supervision is necessary even in the setting of properly monitored quality control strains.
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Affiliation(s)
- A Yechouron
- Department of Microbiology and Infectious Diseases, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec, Canada
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Libman MD, Dascal A, Kramer MS, Mendelson J. Strategies for the prevention of neonatal infection with herpes simplex virus: a decision analysis. Rev Infect Dis 1991; 13:1093-104. [PMID: 1663650 DOI: 10.1093/clinids/13.6.1093] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Decision analysis was used in the evaluation of nine strategies for the prevention of neonatal infection with herpes simplex virus (HSV). These strategies involve physical examination at labor, weekly screening of pregnant women for shedding of HSV, use of serologic methods specific for HSV type 2, and performance of a rapid diagnostic test at labor. Rates of cesarean delivery and of neonatal infection with HSV were estimated for each strategy, and the estimates were compared with those for a strategy of no intervention. The effects of variations in the sensitivities and specificities of the diagnostic and serologic tests used were analyzed. Given the currently available data and technology, physical examination at labor is the optimal strategy if the primary goal is to minimize the ratio of excess cesarean sections to cases of neonatal HSV infection averted.
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Affiliation(s)
- M D Libman
- Department of Medicine, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec, Canada
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Delage G, Turgeon F, Dascal A, Mendelson J, Lescop J. Infectious diseases as a subspecialty in Canada: status of the practice in Quebec. Rev Infect Dis 1991; 13:761-2. [PMID: 1925295 DOI: 10.1093/clinids/13.4.761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Bartter T, Irwin RS, Abraham JL, Dascal A, Nash G, Himmelstein JS, Jederlinic PJ. Zirconium compound-induced pulmonary fibrosis. Arch Intern Med 1991; 151:1197-201. [PMID: 2043021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Despite suspicion that inhalation of zirconium should be capable of causing human pulmonary disease, documentation of zirconium pneumoconiosis in humans has been lacking. We studied a likely case of zirconium compound-induced pulmonary fibrosis. The diagnosis was based on the following: (1) a history of gradual increase in symptoms and slowly progressing pulmonary fibrosis by chest roentgenogram compatible with a pneumoconiosis; (2) an appropriate history of exposure and a latency period of about 15 years before the onset of dyspnea and of roentgenographic changes; (3) analysis of open lung biopsy material revealing end-stage fibrosis and honeycombing, a moderate number of birefringent particles, and extremely high levels of a variety of zirconium compounds; and (4) no other potential cause of fibrosis. We conclude that zirconium should be considered a likely cause of pneumoconiosis and that appropriate precautions should be taken in the workplace.
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Affiliation(s)
- T Bartter
- Division of Pulmonary and Critical Care Medicine, Cooper Hospital, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Camden
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Bartter T, Dascal A. The "toxic strep syndrome": severe group A streptococcal disease in the absence of bacteremia. Rev Infect Dis 1990; 12:1204-5. [PMID: 2267492 DOI: 10.1093/clinids/12.6.1204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Affiliation(s)
- A Dascal
- Sir Mortimer B. Davis--Jewish General Hospital, Montreal, Quebec, Canada
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Gomez-Rodrigo J, Mendelson J, Black M, Dascal A. Streptococcus pneumoniae acute suppurative parotitis in a patient with Sjögren's syndrome. J Otolaryngol 1990; 19:195-6. [PMID: 2192076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A case of suppurative parotitis due to Streptococcus pneumoniae is reported in a patient with Sjögren's syndrome. The rarity of this condition is noted by a review of the literature.
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Affiliation(s)
- J Gomez-Rodrigo
- Department of Microbiology and Infectious Diseases, Sir Mortimer B. Davis Jewish General Hospital, Montreal, Quebec, Canada
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Dascal A, Chan-Thim J, Morahan M, Portnoy J, Mendelson J. Replacement of special enzyme immunoassay transport medium by a standard viral transport medium in the Herpcheck herpes simplex virus antigen detection test. Diagn Microbiol Infect Dis 1989; 12:473-5. [PMID: 2560418 DOI: 10.1016/0732-8893(89)90080-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A new direct herpes simplex virus antigen enzyme immunoassay (EIA) uses a special EIA transport medium (ETM) for transport of herpes simplex virus (HSV) specimens. As ETM lyses the virus precluding culture and typing, we evaluated the relative performance of this EIA when performed on specimens transported in either ETM or a standard viral transport medium (VTM). These EIA results were also compared to cell culture performed on specimens transported in VTM (VTM-CC) and direct rapid inoculation into cell culture (CC). Based on all confirmed positives, by any test, the sensitivities for CC was 97% (66/68), for VTM-CC 91% (62/68), for ETM-EIA 97% (66/68), and for VTM-EIA 93% (63/68). It appears that VTM may be a slightly less desirable substitute than ETM in the performance of EIA. However, VTM-EIA is certainly as sensitive as cell culture performed on VTM.
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Affiliation(s)
- A Dascal
- Department of Medical Microbiology and Infectious Diseases, SMBD-Jewish General Hospital, Montreal, Quebec, Canada
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Brenner BG, Dascal A, Margolese RG, Wainberg MA. Natural killer cell function in patients with acquired immunodeficiency syndrome and related diseases. J Leukoc Biol 1989; 46:75-83. [PMID: 2659714 DOI: 10.1002/jlb.46.1.75] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
This review describes current knowledge of changes in natural killer (NK) cell function in acquired immunodeficiency syndrome (AIDS)-related disorders, vis-à-vis associated abnormalities in NK cytolytic function, NK cell subset distribution, NK cytopathology, and lymphokine regulation. NK cells, which are closely associated with large granular lymphocytes, are spontaneously cytotoxic to tumor and virally infected targets. As such, they may play a role in natural resistance to human immunodeficiency virus type 1 (HIV-1)-associated disorders and other opportunistic infections. Yet, peripheral blood NK activity is frequently reduced in patients with HIV-1-induced disease. NK cells are heterogeneous both with respect to their expression of serologically defined membrane antigens and functional activity. In AIDS-related syndromes, there appears to be a diminution of the NK pool (CD16+ cells) involved in cytolytic function, while there is an elevation of the NK pool that coexpresses NK (Leu 7+) and T (CD8+) cell markers, which show little or no involvement in cytolytic function. The impairment of in vitro NK function is not associated with a reduced frequency of lytic conjugates of effectors and target cells nor with the recycling capacity of these effector cells but rather is associated with defects in the NK cell lytic machinery following formation of such conjugates. NK cells in AIDS patients show an impairment in effector cell microtubule rearrangement following target cell interaction. The causes of NK cell dysfunction in AIDS-related disorders remain unknown. NK cells do not appear to express the CD4 epitope of the HIV receptor, nor have they been demonstrated to be susceptible to infection by HIV-1. There appears to be a preponderance of immature NK cells and a lymphokine imbalance in patients with HIV-1 associated disease. Interleukin-2 can partially restore diminished in vitro NK function. Elucidation of the involvement of the NK compartment in natural resistance to HIV-1 merits further investigation.
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Affiliation(s)
- B G Brenner
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec, Canada
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Dascal A, Chan-Thim J, Morahan M, Portnoy J, Mendelson J. Diagnosis of herpes simplex virus infection in a clinical setting by a direct antigen detection enzyme immunoassay kit. J Clin Microbiol 1989; 27:700-4. [PMID: 2542362 PMCID: PMC267400 DOI: 10.1128/jcm.27.4.700-704.1989] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
A commercial 4-h direct herpes simplex virus (HSV) antigen detection enzyme immunoassay (EIA) kit (Du Pont Herpchek) was evaluated by using 273 clinical specimens obtained in a hospital-based infectious disease practice. The EIA was compared with a standard culture method in which WI38 cells were inoculated within 20 min of sample collection. Cultures were observed for 2 weeks, and positive findings were confirmed by fluorescein-labeled monoclonal antibody (FA) staining. The values for the overall HSV detection rate were 40.7% by the standard culture method and 41.4% by EIA. In eight cases, the EIA was positive, while the culture method was negative; however, clinical data and confirmatory blocking EIA suggested that a true HSV infection was present. For six FA-confirmed, culture-positive samples, the direct EIA was negative; however, an EIA performed on the supernatants of these cultures was positive, suggesting that the failure of the EIA to detect these samples was not due to lack of strain specificity of the test. After confirmatory tests of standard culture and EIA discrepant results, the overall sensitivity of the test was 95.0% (113 of 119) and the specificity was 100% (154 of 154).
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Affiliation(s)
- A Dascal
- Department of Microbiology and Infectious Diseases, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
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Wainberg MA, Dascal A, Blain N, Fitz-Gibbon L, Boulerice F, Numazaki K, Tremblay M. The effect of cyclosporine A on infection of susceptible cells by human immunodeficiency virus type 1. Blood 1988; 72:1904-10. [PMID: 2904290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The effect of cyclosporine A (CyA) on the ability of the human immunodeficiency virus type 1 (HIV-1) to infect the H-9 T-cell leukemic line, as well as interleukin-2 (IL-2)-grown human peripheral blood-derived lymphocytes, has been studied. Pretreatment of H-9 cells and human lymphocytes with CyA over 24 hours completely prevented viral infection over a 21-day period, whereas the addition of drug at two hours postinfection with HIV-1 had a significant inhibitory effect on viral replication and expression of the virus-specific antigens p17 and p24. However, if CyA was added at later times to these lymphocytic cells, this inhibitory effect was lost. Indeed, the removal of CyA from cultures that had been treated from two hours after infection led to the rapid production of progeny virus. HIV-1 was able to infect peripheral blood lymphocytes obtained from each of four kidney allograft recipients on long-term CyA antirejection therapy, as long as drug was not included in the culture medium. In addition, we asked what effect pretreatment with CyA of cells of the U-937 monocytic line and primary cultures of human monocytes/macrophages might have on infection by HIV-1. CyA had no demonstrable effect on the ability of HIV-1 to infect cells of either type.
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Affiliation(s)
- M A Wainberg
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis, Jewis General Hospital, Montreal, Quebec, Canada
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Abstract
Three patients presented with multisystem disease that shared many of the features of toxic shock syndrome. Bacteriologic and serologic evidence strongly suggested that group A beta-hemolytic Streptococcus had caused the illnesses. Group A streptococcal infection may be an underdiagnosed cause of a toxic streptococcal syndrome, a syndrome of multisystem disease apparently mediated by toxins.
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Affiliation(s)
- T Bartter
- Division of Pulmonary and Critical Care Medicine, University of Massachusetts Medical School, Worcester
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Abstract
The antimicrobial susceptibility profiles of a total of 318 aerobic and facultatively anaerobic bacteria (255 gram-negative bacilli and 63 gram-positive cocci) were determined, using a new commercially available breakpoint broth microdilution procedure (Sensititer Breakpoint System (SBS), Gibco Diagnostics, Inc., Madison, WI) that categorizes test results in the form of susceptibility categories: susceptible, intermediate, and resistant. Results obtained with the SBS were compared with those achieved with a standardized disk diffusion procedure. Among a total of 4,414 organism-antimicrobic comparisons, concordance between the results of the SBS and the disk diffusion procedure was observed in 3,888 cases (88.1%). Four hundred twenty-three (9.6%) minor discrepancies, 45 (1.0%) major discrepancies, and 58 (1.3%) very major discrepancies were noted. Arbitration of major and very major discrepancies with a full-range minimum inhibitory concentration (MIC) procedure confirmed the results of the SBS in 53.4% of cases. A single organism-antimicrobial combination, the nonenterococcal streptococci tested against the aminoglycosides, yielded a significant number of very major errors which were arbitrated in favor of the disk diffusion result. These errors were probably due to poor growth of the test organism in the broth medium used for performing the SBS test (i.e., cation-supplemented Mueller-Hinton broth). With this exception, the SBS was found to be at least as accurate as the standardized disk diffusion procedure.
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Dascal A, Gleckman R. Serial knee infections with enteric pathogens. Hosp Pract (Off Ed) 1984; 19:32I, 32L, 32P. [PMID: 6430931 DOI: 10.1080/21548331.1984.11702883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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