GaryP. Wormser

Quantitation of cell-associated borrelial DNA in the blood of Lyme disease patients with erythema migrans

Bloodstream invasion is an important event in the pathogenesis of the more serious manifestations of Lyme disease. The number of spirochetes in the blood of infected patients, however, has not been determined, and, therefore, it is unknown whether the number of spirochetes can be correlated with particular clinical or laboratory features. This study was designed to measure the level of Borrelia burgdorferi in the plasma of Lyme disease patients and correlate these levels with selected clinical and laboratory findings. Nested and quantitative polymerase chain reaction (qPCR) was employed to detect cell-associated flaB gene DNA in the plasma of untreated early Lyme disease patients with erythema migrans (EM). Twenty-nine (45.3%) of 64 patients had evidence of B. burgdorferi in their plasma by at least one of the PCR methods. For the 22 qPCR-positive patients, the mean number of flaB gene copies per mL of plasma was 4,660, with a range of 414 to 56,000. The number of flaB gene copies did not significantly correlate with any of the clinical, demographic, or laboratory variables assessed. For reasons discussed, we suggest caution in extrapolating an estimate of the number of viable Borrelia in plasma from the observed number of flaB copies.

Evaluation of antibiotic combinations against multidrug-resistant Acinetobacter baumannii using the E-test

In view of the current lack of single antimicrobial agents available to treat infections due to certain strains of multidrug-resistant (MDR) Acinetobacter baumannii, the efficacy of various antibiotic combinations was evaluated using the E-test method. The antibiotic combinations were tested on a convenience sample of 10 clinical isolates of MDR A. baumannii, and the combination of imipenem with either colistin or amikacin was found to be synergistic in vitro against a predominant group of the isolates. The clinical significance of this finding needs to be determined since MDR A. baumannii has been a serious nosocomial health issue for the last several years [1–3]. In 1999, hospitals in Brooklyn, NY, USA, reported that 53% of 419 isolates of A. baumannii recovered over a 3-month period were resistant to imipenem [3]. For our study, a convenience sample of 10 clinical isolates of A. baumannii (stored at −70◦F), was chosen based on the resistance of the isolates to almost all single antimicrobial agents, as determined by the Microscan system’s gram-negative breakpoint panels (Dade Behring, West Sacramento, CA, USA). The isolates were recovered from 10 different patients hospitalized at a tertiary care medical center in the greater New York City metropolitan area between 1999 and 2003. The isolates’ sources were

Efficacy of an OspA vaccine preparation for prevention of lyme disease in New York State

SummaryA multicenter, double-blinded, placebo-controlled study was done comparing a 30-μg dose of a single protein recombinant OspA vaccine preparation with a saline placebo for efficacy in prevention of Lyme disease in humans. The OspA vaccine (30-μg dose) or saline placebo was given intramuscularly at day 0,1 month later, and 12 months later. Cases of possible Lyme disease were evaluated clinically and using culture, polymerase chain reaction and immunoblot assays. Safety data are being analyzed separately. 1,634 adult volunteers were enrolled at a single center in New York State. Vaccine efficacy during the first year was 40% and during the second 37%. Compared with placebo, the OspA vaccine significantly reduced the frequency of Lyme disease during the 2-year study period (P<0.04, one-tailed Fisher’s exact test). Vaccine efficacy was restricted to volunteers under 60 years old (50% vs 9%, P<0.03, two-tailed Fisher’s exact test). A recombinant OspA vaccine preparation was found to have moderate activity in preventing Lyme disease in adults under 60 years old from New York State. Reasons for vaccine failure need to be addressed and a risk benefit ratio calculated.