Application of PCR to multiple specimen types for diagnosis of cytomegalovirus infection: comparison with cell culture and shell vial assay.

Human cytomegalovirus (CMV) is a herpesvirus that is responsible for significant morbidity and mortality in congenitally infected infants and immunocompromised patients. Antiviral therapies are available, thus making timely diagnosis of significant importance to at-risk patients. A PCR system was devised. The newly devised system, unlike previously described systems, can be applied to a wide variety of specimen types in a clinical microbiology laboratory setting. Specimens from all sites routinely accepted for CMV culture were shown to be acceptable for CMV PCR. Sensitivity and specificity were established in comparison with those of both monolayer culture and shell vial assay (SVA). The sensitivity and specificity of PCR for detection of CMV in specimens exclusive of urine and blood were 97.5 (77 of 79 specimens) and 87.2% (41 of 47 specimens), respectively. The sensitivity and specificity of PCR for urine and blood specimens were 100 (10 of 10) and 95.7% (45 of 47) and 66.7 (4 of 6) and 78.8% (41 of 52), respectively. Discrepancies of positive PCR results with negative culture or SVA results occurred for specimens flanked chronologically by other culture- or SVA-positive specimens and were likely culture failures, increasing the specificity (100%) of PCR. Discrepancies of negative PCR results with positive culture or SVA results occurred in specimens with few cells or infectious foci by SVA or culture and may represent sampling variability associated with low virus titers.

Transplantation: the role of microbiologic services.

The role of microbiologic services in transplantation is described. Transplantations have become widely accepted therapeutic practices in which the microbiology laboratory actively participates. Except for problems related to function and rejection of the transplanted organ, infections are the most important concern of the clinician. The infections can be caused by bacteria, fungi, protozoa, and viruses and may occur very early after surgery or as long as six months posttransplant. Specimens (sputum, throat, blood, stool, perirectal, and urine) are routinely sent to the microbiology laboratory before and after transplantation to aid in the diagnosis of potential infections. Rapid diagnostic tests are imperative, and results must be communicated to clinicians expeditiously; this information may be critical in guiding therapy of these infections. The microbiology laboratory plays an essential role in identifying etiologic agents of infections and in determining appropriate therapy.

Rapid serological diagnosis of Aspergillus fumigatus infection of the frontal sinuses and nasal chambers of the dog.

Aspergillus fumigatus precipitins in dog sera were detected by counterimmunoelectrophoresis (CIE). The procedure gave results within 90 minutes compared with 72 to 96 hours required in agar-gel double diffusion. Culture-filtrate antigens from two-week-old cultures of A fumigatus and two-day-old mycelial antigens produced the strongest reactions in CIE tests and the former antigen also revealed high titres in tests with serum from seven of 14 dogs with A fumigatus precipitins. Serum from these 14 dogs also reacted in CIE tests with a number of Penicillium species antigens.