Christiane Gaudreau

Thiamine deficiency and wernicke's encephalopathy in AIDS

Several neuropathological reports in the last 5 years have described brain lesions characteristic of Wernickes Encephalopathy in patients with AIDS. Using the erythrocyte transketolase activation assay, we now report biochemical evidence of thiamine deficiency in 9/39 (23%) of patients with AIDS or AIDS-related complex. In no cases was there history of alcohol abuse nor were there clinical signs of Wernickes Encephalopathy. Thiamine deficiency in these patients most likely results from the cachexia and catabolic state characteristic of AIDS. In view of (i) the confirmed neuropathological evidence of Wernickes Encephalopathy in AIDS patients, (ii) the significant thiamine deficiency in these patients and (iii) the difficulties of clinical diagnosis of Wernickes Encephalopathy, it is recommended that dietary thiamine supplementation be initiated in all newly diagnosed cases of AIDS or AIDS-related complex.

Antimicrobial Resistance of Campylobacter jejuni subsp. jejuni Strains Isolated from Humans in 1998 to 2001 in Montréal, Canada

ABSTRACT The rates of resistance of 51 to 72 human strains of Campylobacter jejuni subsp. jejuni isolated annually from 1998 to 2001 in Montréal, Québec, Canada, varied from 1 to 12% for erythromycin, 43 to 68% for tetracycline, and 10 to 47% for ciprofloxacin. In the last years of the study, there was a significant increase in the rate of resistance to ciprofloxacin (P = 0.00003) but not in the rate of resistance to erythromycin (P = 0.056) or tetracycline (P = 0.095) compared to the rate obtained in the first years. All 51 C. jejuni strains isolated in 2001 were susceptible to gentamicin, amoxicillin-clavulanic acid, imipenem, and meropenem. From 1999 to 2001, 74 strains of C. jejuni acquired abroad were significantly more resistant to ciprofloxacin than 109 strains of C. jejuni acquired locally (66 versus 9%, P < 0.00001) but were not significantly more resistant to erythromycin (1 versus 6%, P = 0.15) or to tetracycline (55 versus 58%, P = 0.87).

Epidemiology and Antimicrobial Susceptibilities of 111 Campylobacter fetus subsp. fetus Strains Isolated in Québec, Canada, from 1983 to 2000

ABSTRACT The epidemiology and antimicrobial susceptibilities of 111 Campylobacter fetus subsp. fetus strains isolated from 103 patients from 1983 to 2000 in Québec, Canada, were determined. The median number of patients infected annually with this bacteria was seven, with an incidence of 0.1 per 100,000 population. The male-to-female ratio was 1.1 to 1.0. The patients originated from 13 of the 18 Québec socioeconomic regions. The age range of the patients was 6 months to 90 years old, 53% being ≥70 years old and 2% being <20 years old. The isolation site was blood for 69% of the patients, stools for 20%, and other body fluids for 11% of them. Three patients suffered a relapse, with the same strain being isolated from the same site at different times as confirmed by pulse-field gel electrophoresis. All isolates were susceptible to ampicillin, gentamicin, meropenem, and imipenem, with 90% minimal inhibitory concentrations of 4, 1, 0.12, and ≤0.06 μg/ml, respectively. Three percent and two percent of the strains were, respectively, resistant and intermediate to ciprofloxacin. Thirty-four percent of the strains were resistant to tetracycline. There was a nonsignificant increase in resistance to ciprofloxacin (P = 0.27) and to tetracycline (P = 0.65) in recent years. The percentages of intermediate and resistant MICs were, respectively, 12 and 1% for cefotaxime and 71 and 0% for erythromycin. All strains were β-lactamase negative.

Clindamycin with Primaquine vs. Trimethoprim-Sulfamethoxazole Therapy for Mild and Moderately Severe Pneumocystis carinii Pneumonia in Patients with AIDS: A Multicenter, Double-Blind, Randomized Trial (CTN 004)

This double-blind, randomized, multicenter trial compared clindamycin/primaquine (Cm/Prq) with trimethoprim-sulfamethoxazole (TMP-SMZ) as therapy for AIDS-related Pneumocystis carinii pneumonia (PCP). Forty-five patients received clindamycin (450 mg four times daily [q.i.d.]) and primaquine (15 mg of base/d); 42 received TMP-SMZ (320 mg/1,600 mg q.i.d. if weight of > or = 60 kg or 240 mg/1,200 mg q.i.d. if weight of < 60 kg) plus placebo primaquine. Overall, the efficacy of Cm/Prq was similar to that of TMP-SMZ (success rate, 76% vs. 79%, respectively); Cm/Prq was associated with fewer adverse events (P = .04), less steroid use (P = .18), and more rashes (P = .07). These differences were even greater for patients with PaO2 of > 70 mm Hg (P = .02, P = .04, and P = .02, respectively). For patients with PaO2 of < or = 70 mm Hg (23 Cm/Prq recipients and 21 TMP-SMZ recipients), the efficacy of Cm/Prq was similar to that of TMP-SMZ (success rate, 74% vs. 76%, respectively); Cm/Prq was associated with similar adverse events (P = .57), steroid use (P = .74), and rashes (P = .78). This trial confirms that Cm/Prq is a reasonable alternative therapy for mild and moderately severe PCP.

Role of the beta-lactamase of Campylobacter jejuni in resistance to beta-lactam agents.

We studied the role of the beta-lactamase of Campylobacter jejuni in resistance to beta-lactam agents. beta-Lactamase-positive strains were more resistant than beta-lactamase-negative strains to amoxicillin, ampicillin, and ticarcillin (P less than 0.05). With penicillin G, piperacillin, imipenem, and six cephalosporins, the susceptibility levels were similar for both beta-lactamase-positive and -negative strains. By using spectrophotometric and microbiological assays, the beta-lactamase from three strains hydrolyzed ampicillin, amoxicillin, penicillin G, cloxacillin, and, partially, cephalothin. Ticarcillin and piperacillin were partially hydrolyzed in the microbiological assay. There was no activity against five other cephalosporins or imipenem. Isoelectric focusing of the enzyme showed a pI of 8.8. Tazobactam was the best inhibitor of the enzyme, followed by clavulanic acid, sulbactam, and cefoxitin, while EDTA and p-chloromercuribenzoate had no activity. All beta-lactamase-positive strains became susceptible to amoxicillin and ampicillin with 1 micrograms of clavulanic acid per ml. With the same inhibitor, there was a reduced but significant effect for ticarcillin but no effect for penicillin G or piperacillin. Sulbactam had no effect and tazobactam was effective only at 2 micrograms/ml on amoxicillin and ampicillin. The beta-lactamase of C. jejuni seems to be a penicillinase with a role in resistance for only amoxicillin, ampicillin, and ticarcillin.

Prosthetic hip joint infection with a Streptococcus agalactiae isolate not susceptible to penicillin G and ceftriaxone

Microbiologie medicale et infectiologie, Centre hospitalier de l’Universite de Montreal (CHUM)-Hopital Saint-Luc, 1058 rue Saint Denis, Montreal, Quebec, Canada, H2X 3J4; Departement de microbiologie et immunologie, Universite de Montreal, CP 6128 succ. Centre-Ville, Montreal, Quebec, Canada, H3C 3J7; Medecine interne, CHUM-Hopital Saint-Luc, 1058 rue Saint Denis, Montreal, Quebec, Canada, H2X 3J4; Laboratoire de sante publique du Quebec/Institut national de sante publique du Quebec (LSPQ/ INSPQ), 20045 chemin Sainte-Marie, Sainte-Anne-de-Bellevue, Quebec, Canada, H9X 3R5; Microbiologie medicale et infectiologie, CHUM-Hopital Notre-Dame, 1560 rue Sherbrooke Est, Montreal, Quebec, Canada, H2L 4M1

Comparison of SmaI-defined genotypes of Campylobacter jejuni examined by KpnI: a population-based study.

Pulsed-field gel electrophoresis (PFGE) was used to analyse 147 isolates collected in two regions of Quebec province (Estrie and Montreal) between March 1998 and Feb. 1999, to determine the utility of molecular strain typing for a population-based collection of Campylobacter jejuni and to compare directly the discriminatory power of SmaI and KpnI restriction digests. With a combination of epidemiological criteria including space and time plus molecular strain typing, 49% of isolates from Estrie and 39% of isolates from Montreal were identified as belonging to a putative cluster. For 41% of the cases, sources were either missing or explicitly unknown; the remaining sources were subject to recall bias. Thus, the evaluation of sporadic cases of campylobacter enteritis by descriptive clinical investigation alone is neither sensitive nor reliable for identifying sources of infection. In the PFGE analysis, KpnI digests provided appreciably greater discriminatory power than SmaI digests. When combining the PFGE analyses with basic epidemiological criteria, 30% of the putative SmaI clusters were inconsistent with the epidemiological criteria compared with 17% of the KpnI clusters. Among the 98 isolates assigned to clusters by SmaI, only 65% gave concordant results with KpnI. In contrast, among the 81 isolates assigned to clusters by KpnI, 92% gave concordant results with SmaI. Finally, clusters that were epidemiologically related to ingestion of raw milk and specific water sources correlated better with the typing results based on KpnI than SmaI. Thus, KpnI is the enzyme of choice for molecular epidemiology studies of C. jejuni. The combination of continuous epidemiological surveillance and molecular strain typing may be useful for identifying new sources and mechanisms of transmission for community-acquired C. jejuni infection andultimately for developing new approaches to prevention.

Streptococcus pseudoporcinus sp. nov., a Novel Species Isolated from the Genitourinary Tract of Women

ABSTRACT Streptococcus strains from animal and human sources identified biochemically as Streptococcus porcinus were investigated by 16S rRNA gene sequencing. The nine human strains isolated between 1997 and 2005 formed a single cluster with more than 2.1% dissimilarity with S. porcinus strains from animal sources. A novel species, Streptococcus pseudoporcinus sp. nov., is proposed.

Comparison of Disk Diffusion and Agar Dilution Methods for Erythromycin and Ciprofloxacin Susceptibility Testing of Campylobacter jejuni subsp. jejuni

ABSTRACT Disk diffusion was a reliable, easy, and inexpensive method for testing the susceptibility of Campylobacter jejuni to erythromycin (215 susceptible and 45 resistant isolates) and to ciprofloxacin (154 susceptible, two intermediate, and 124 resistant isolates) using, respectively, an erythromycin disk and ciprofloxacin and nalidixic acid disks.

Performance of an Agar Dilution Method and a Vitek 2 Card for Detection of Inducible Clindamycin Resistance in Staphylococcus spp.

ABSTRACT The D-zone test detects inducible clindamycin resistance in Staphylococcus spp. Two other methods not described by the Clinical and Laboratory Standards Institute (CLSI) are available to test for this resistance mechanism: an agar dilution method and new Vitek 2 cards. This study evaluated the performance of both methods in detecting inducible clindamycin resistance. Nonduplicate clinical strains of Staphylococcus spp. (111 Staphylococcus aureus and 52 coagulase-negative staphylococcus strains), intermediate or resistant to erythromycin but susceptible to clindamycin, were obtained from three hospitals in Montreal, Quebec, Canada. Molecular analysis to detect resistance genes was conducted on all strains. A Mueller-Hinton agar containing 1 mg of erythromycin and 0.5 mg of clindamycin/liter was used for the dilution method, and two inocula were tested: 104 and 105 CFU per spot. Plates were read at 24 and 48 h. The Vitek 2 AST-P580 card was used according to the manufacturers recommendations. The results were compared to those of the D-zone test. The D-zone test was positive in 134 of 163 (82%) strains. With the 104 CFU inoculum, the sensitivities were 84 and 99% at 24 and 48 h, respectively. The 105 CFU inoculum increased the sensitivities at 24 and 48 h to 91 and 100%, respectively. The specificity was 100% for the 104 CFU inoculum at 24 h and 97% for the other combinations. The sensitivity and specificity for the Vitek 2 card were 93 and 100%, respectively. The performance of both the agar dilution method and the Vitek 2 card was good, but these methods were not as sensitive as the D-zone test at 24 h.