Diagnosis of neonatal enterovirus infection by polymerase chain reaction

A 5-hour colorimetric polymerase chain reaction (PCR) assay was more sensitive than viral culture in identifying viral infection in initial serum (13/16 vs 5/16; p = 0.008) and urine (10/16 vs 5/16; p = 0.2) specimens from 16 enterovirus-infected newborn infants, and remained more sensitive throughout their illnesses. Combined sensitivity of serum and urine PCR was 14 of 16 (88%). Results of all acute-phase PCR assays of serum and urine from four neonates with cultures negative for enterovirus were also negative. PCR assay of serum and urine facilitates rapid, accurate diagnosis of neonatal enterovirus infections.

Diagnosis of enteroviral meningitis by using PCR with a colorimetric microwell detection assay

A 5-h, user-friendly PCR assay for the diagnosis of enteroviral meningitis was developed. Reverse transcription and amplification were performed in a one-step reaction using rTth polymerase. Carryover contamination was prevented with dUTP and uracil N-glycosylate. Detection was performed colorimetrically on a microwell titer plate. Sensitivity, specificity, positive predictive value, and negative predictive value were 94.7, 97.4, 94.7, and 97.4%, respectively.

PCR primers and probes for the 16S rRNA gene of most species of pathogenic bacteria, including bacteria found in cerebrospinal fluid

A set of broad-range PCR primers for the 16S rRNA gene in bacteria were tested, along with three series of oligonucleotide probes to detect the PCR product. The first series of probes is broad in range and consists of a universal bacterial probe, a gram-positive probe, a Bacteroides-Flavobacterium probe, and two probes for other gram-negative species. The second series was designed to detect PCR products from seven major bacterial species or groups frequently causing meningitis: Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, S. agalactiae, Escherichia coli and other enteric bacteria, Listeria monocytogenes, and Staphylococcus aureus. The third series was designed for the detection of DNA from species or genera commonly considered potential contaminants of clinical samples, including cerebrospinal fluid (CSF): Bacillus, Corynebacterium, Propionibacterium, and coagulase-negative Staphylococcus spp. The primers amplified DNA from all 124 different species of bacteria tested. Southern hybridization testing of the broad-range probes with washes containing 3 M tetramethylammonium chloride indicated that this set of probes correctly identified all but two of the 102 bacterial species tested, the exceptions being Deinococcus radiopugnans and Gardnerella vaginalis. The gram-negative and gram-positive probes hybridized to isolates of two newly characterized bacteria, Alloiococcus otitis and Rochalimaea henselii, as predicted by Gram stain characteristics. The CSF pathogen and contaminant probe sequences were compared with available sequence information and with sequencing data for 32 different species. Testing of the CSF pathogen and contaminant probes against DNA from over 60 different strains indicated that, with the exception of the coagulase-negative Staphylococcus probes, these probes provided the correct identification of bacterial species known to be found in CSF.

Comparative diagnosis of neonatal chlamydial conjunctivitis by polymerase chain reaction and McCoy cell culture

Cervical and ocular swabs from 100 mother/newborn pairs delivering on the clinic service were assayed for Chlamydia trachomatis with standard McCoy cell culture and with standard and biotinylated polymerase chain reaction techniques, using primers directed against the major outer membrane protein gene and C. trachomatis-specific cryptic plasmid, respectively. Using the polymerase chain reaction, 20 (20%) mothers and seven (7%) neonates were positive for Chlamydia. All neonates positive by polymerase chain reaction were from mothers positive by polymerase chain reaction, yielding a 35% transmission rate. Only five of 20 (25%) mothers and two of seven (28%) neonates positive by polymerase chain reaction were positive by cell culture. All cell culture samples were positive by polymerase chain reaction testing. Culture and polymerase chain reaction analysis two weeks after treatment with oral erythromycin were negative. The polymerase chain reaction assay appears to be equally specific and more sensitive than McCoy cell culture for the detection of C. trachomatis from ocular specimens.

The use of polymerase chain reaction for the detection of chlamydial keratoconjunctivitis

Ocular swabs from 30 consecutive patients with follicular conjunctivitis were screened for Chlamydia trachomatis, herpes simplex virus, and adenovirus by a variety of laboratory techniques. For the detection of C. trachomatis, we compared two polymerase chain reaction methods, McCoy cell culture isolation, and the direct fluorescein-conjugated monoclonal antibody test. Four of 30 patients tested positive for C. trachomatis by using both conventional and biotinylated polymerase chain reaction methods. Two of the four patients were also McCoy cell culture-positive for C. trachomatis and one of four patients tested positive by using a fluorescein-conjugated chlamydial monoclonal antibody test. All four patients responded to oral antibiotic treatment. On follow-up testing, all four patients were polymerase chain reaction-negative, McCoy cell culture-negative, and fluorescein-conjugated antibody test-negative for C. trachomatis. The polymerase chain reaction appears to be an equally specific and more sensitive method than McCoy cell culture or fluorescein-conjugated antibody testing for the detection of C. trachomatis from ocular specimens.

Use of multiple markers for investigation of an epidemic of Shigella sonnei infections in Monroe County, New York

Antibiotic susceptibility patterns, plasmid profiles, and endonuclease restriction analysis of plasmid DNA were used in the investigation of an epidemic of Shigella sonnei infections in Monroe County, New York, in 1988 and 1989. The epidemic peaked during the winter, included the simultaneous transmission of the disease from person to person and from common food sources, and especially affected inhabitants of the poor, inner-city neighborhoods, young children of both sexes, and women. Resistance to ampicillin, tetracycline, or trimethoprim-sulfamethoxazole, encoded in a 70-MDa plasmid, was found in most of the examined isolates. Unexpectedly, isolates from patients involved in a food-borne outbreak exhibited three different antibiotic susceptibility patterns, suggesting deletion of antibiotic resistance determinants in some strains. Antibiograms clearly separated food-borne outbreak-related and non-foodborne outbreak-related strains, distinguished more strains than did the plasmid profiles, and were useful in tracing the dissemination of individual isolates in the community. Restriction endonuclease analysis substantially increased the discriminatory value of plasmid profiles and validated the antibiogram results. The present study illustrates the complexity of epidemics of S. sonnei infections and shows the value of combining different biological markers in the investigation.