Diagnosis of Pneumocystis carinii pneumonia is based on the identification of the various stages of the parasite in lung samples by standard staining techniques. We therefore assessed the value of the PCR for detection of P. carinii in bronchoalveolar lavage, induced sputum, and blood samples relative to that of standard staining techniques.

The mode of Pneumocystis carinii transmission is controversial. Recent studies point to exogenous inoculation rather than reactivation, and person-to-person transmission has also been suggested. Comparison of nucleotide sequences of the large-subunit mitochondrial rRNA gene of P. carinii from human immunodeficiency virus-seropositive patients showed strain differences. Pneumocystis cannii pneumonia (PCP) remains the most frequent opportunistic infection in AIDS. Despite major improvements in diagnosis and therapy, epidemiological data are fragmentary. Recent studies indicate that P. carinii is rarely detectable by sensitive techniques such as PCR in bronchoalveolar lavage (BAL) fluid or lung biopsy specimens from patients without PCP (1, 9, 11). This suggests that exogenous inoculation rather than reactivation may be involved in PCP. Contamination through inhalation of cysts does occur, but the mode of transmission, whether environmental and/or from infected individuals, is uncertain. The occurrence of small epidemics in human immunodeficiency virus-seronegative patients hospitalized simultaneously with HIV-seropositive patients suggests that nosocomial infection can occur (2, 4, 5). Antigenic studies (7, 16) and karyotyping techniques such as pulsed-field gel electrophoresis have revealed genetic variations in P. carinii strains infecting humans, ferrets, and rats (10, 13, 14). It has also been demonstrated that coinfection with different P. carnii strains in the same host is possible (3, 6). Recently it was shown that humans are infected by multiple strains of P. carinii (8). In the preliminary study presented here, we attempted to identify different strains of P. carinii by studying genomic variations in a fragment of the gene encoding the large subunit of mitochondrial rRNA of human P. cannii isolates. This study was conducted in two Paris hospitals (HBpital Saint-Antoine and Hopital Tenon) between February 1992 and May 1994. We examined P. carinii DNA in 37 BAL specimens from 28 HIV-seropositive patients with PCP proven by direct examination with standard stains (Giemsa and toluidine blue 0) and indirect immunofluorescence. Two or three BAL procedures were performed for 8 of the 28 patients who showed no improvement after receiving specific therapy. BAL fluid was centrifuged, and DNA in the pellet was prepared by proteinase K digestion followed by phenol-chloroform extraction. P. carinii DNA was amplified by PCR with the primer pairs and cycle conditions described by Wakefield et al. (15). The PCR products were electrophoresed in a 2% agarose gel with 1 x tris-borate-EDTA and ethidium bromide and purified by using the Wizard PCR Preps DNA Purification

Pneumocystis curinii (Pc) hominis remains the most frequent opportunistic agent of pneumonia in immunocompromised patients, especially those with AIDS, but the mode of transmission is still uncertain. The hypothesis of reactivation of latent Pc hominis in lung had long been presumed but recent studies indicate that Pc hominis is rarely detectable by sensitive techniques such as the polymerase chain reaction (PCR) in patients without Pc pneumonia (PCP) (5) and thus point to de novo contamination. Small outbreaks have also suggested that this contamination can occur from infected individuals or &om Pc present in ambient air. In a previous work, we identified several strains of Pc hominis and showed that during a given episode,

This review is the fruit of multidisciplinary discussions concerning the continuous administration of beta-lactams, with a special focus on cefepime. Pooling of the analyses and viewpoints of all members of the group, based on a review of the literature on this subject, has made it possible to test the hypothesis concerning the applicability of this method of administering cefepime. Cefepime is a cephalosporin for injection which exhibits a broader spectrum of activity than that of older, third-generation cephalosporins for injection (cefotaxime, ceftriaxone, ceftazidime). The specific activity of cefepime is based on its more rapid penetration (probably due to its zwitterionic structure, this molecule being both positively and negatively charged) through the outer membrane of Gram-negative bacteria, its greater affinity for penicillin-binding proteins, its weak affinity for beta-lactamases, and its stability versus certain beta-lactamases, particularly derepressed cephalosporinases. The stability of cefepime in various solutions intended for parenteral administration has been studied, and the results obtained demonstrated the good compatibility of cefepime with these different solutions. These results thus permit the administration of cefepime in a continuous infusion over a 24-h period, using two consecutive syringes.

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