Richard C. Tilton

Rapid methods and automation in microbiology and immunology

Nucleic Acid Detection.- Controlled Synthetic Oligonucleotide Networks for the Detection of Pathogenic Organisms.- Chemiluminescence: Nucleic Acid Detection for the Future.- Q-Beta Amplification Assays.- Nucleotide Sequence Determination As a Diagnostic Tool.- Bacterial Diagnosis by Detection of rRNA.- Targeting Ribosomal RNA Sequences: A Universal Approach for the Detection and Identification of Microorganisms.- Phylogenetic Identification of Uncultivated Microorganisms in Natural Habitats.- rRNA Probes as Tools for Molecular Epidemiology of Microbial Infections.- Current Methods for Detection of DNA/Ribosomal RNA Hybrids.- Development and Application of Ribosomal Ribonucleic Acid Probes for Species-Specific Detection of Microbial Pathogens.- Immunoassays.- How to Optimize Rapid and Simple Immunoassays.- Noninstrumental Detection of Influenza Viruses by Enzyme Immunoassay.- Application of Dot Immunobinding Assay (DIBA) and Reversed Passive Hemagglutination Assay (RPHA) in Detection of Shigella flexneri from Fecal Samples.- Synthetic Peptides in Antibody Assays.- Peptides as Specific Recognition Devices.- The Significance of IgG Peptides and Sugars for the Development of Autoimmunity in Rheumatoid Arthritis.- Synthetic Peptides Derived from HIV-1, HIV-2, and HTLV I Envelope Proteins in Human Retrovirus Serology.- Flow Cytometry in Diagnosis of Infectious Diseases.- Analysis of Bacteria in Environmental and Medical Microbiology by Flow Cytometry.- Measurement of CD8 Subsets Discriminates Among Clinical Stages of HIV-1 Infected Patients.- Analysis by Flow Cytometry of Interferon-?-Expressing Lymphocytes as a Method for the Rapid Diagnosis of Viral Infection.- Bacterial Growth Monitoring.- Automated Detection of Bacterial Growth for Susceptibility Testing.- Image Analysis for the Assessment of Bacterial Growth.- Conductance and Impedance Methods for Detecting Pathogens.- Assay of Antimicrobial Agents.- Concentrations of Parenterally Administered Antimicrobial Agents in Faeces in Relation to Changes in the Human Intestinal Microflora.- Pharmacokinetic Aspects of Antibiotic Assays.- The Assay of New Antimicrobials and the Penetration of Drugs into Tissues.- Clinical Needs for Assays of New Antimicrobial Agents.- Borrelliosis.- Laboratory Detection of Lyme Borrelliosis.- Addressing the Antiquity of Lyme Disease: Detection of B. burgdorferi DNA in Museum Specimens of Ixodes dammini.- New Understanding of the Epidemiology of Lyme Disease.- Mycobacterial Diagnosis.- Current Methods for Rapid Detection and Identification of Mycobacteria.- Detection and Identification of Mycobacterium Species Using Gene Amplification Techniques.- Application of Gene Amplification to Clinical Mycobacteriology Laboratories.- Identification of Mycobacteria by ELISA using Monoclonal Antibodies.- Serological Tests for the Diagnosis of Tuberculosis and Leprosy.- A Rapid System for the Identification of Mycobacteria.- Chlamydia pneumoniae Infections.- Chlamydia pneumoniae, Strain TWAR, a New Important Pathogen.- Culture and Rapid Methods in Diagnosis of Chlamydia pneumoniae Infections.- New Approaches in the Etiological Diagnosis of Acute Chlamydia pneumoniae Infections.- Problems in Diagnosis of Chronic Chlamydia pneumoniae Infections.- Human Retroviral Infections.- Priorities in AIDS Diagnostics in the 1990s: Towards the Monitoring of Virus Replication.- Epidemiology of HTLV-I in Africa.- Diagnosis of Papillomavirus Infections.- Detection of Genital Human Papilloma Virus Infections by the Polymerase Chain Reaction.- The Antibody Response to Human Papillomavirus.- Rapid Diagnosis of Mycoses.- Evaluation of Commercial Kits and Systems for the Rapid Identification and Biotyping of Yeasts.- The Diagnosis and Management of AIDS Patients with Mycotic Infections.- Rapid Serodiagnostic Procedures for the Mycoses.- The Importance of and Increasing Need for Rapid Detection of Mycotic Agents.- New Methods for the Diagnosis of Parasitic Infections.- DNA Probes on the Diagnosis of Parasitic Infections.- Ribosomal RNA is an Effective Target for the Species-Specific Detection of Malaria Parasites.- Diagnosis of Filariasis with DNA Probes.- Detection of Malaria-Infected Mosquitoes by a Two-Site Immunoassay.- Environmental Microbiology.- Newer Applications in Environmental Analyses.- The Polymerase Chain Reaction and Gene Probes for Detection of Waterborne Pathogens.- Rapid, Specific, Defined Substrate Technology Colilert System for the Simultaneous Detection of Total Coliforms and Escherichia coli from Water.- Immunoassays to Detect Environmental Contaminants.- Applying Genetic Ecology to Environmental Management.- Detection of Foodborne Pathogens.- Hydrophobic Grid Membrane Filter Methods for Detection of Foodborne Pathogens.- Identification of Foodborne Pathogens by Nucleic Acid Hybridization.- Immunological Methods for Detection of Foodborne Pathogens and Their Toxins.- Impediometric Methods for the Detection of Foodborne Pathogens.- Microbial Detection and Control in the Food Industry.- Rapid Methods in the Food Industry.- Microbiological Instrumentation for the Food Industry: A Review.- Rapid Methods in the Dairy Industry.- Rapid Methods of Microbial Determination and Enumeration for the Meat Industry.- Rapid Methods in the Poultry Industry.- Rapid Diagnostic Methods for Field Laboratories.- Rapid Diagnostic Tests for Field Laboratories in Developing Countries.- Rapid Diagnosis of Viral Infection.

Single dose azithromycin treatment of gonorrhea and infections caused by C. trachomatis and U. urealyticum in men

BACKGROUND AND OBJECTIVES Single dose regimens have advantages in the treatment of STD. Azithromycin has unique pharmacokinetics that may make single dose regimens feasible. Treatment with a single 1 g dose of azithromycin was compared to 100 mg doxycycline twice daily for seven days. STUDY DESIGN This was a randomized third-party blinded study on 183 male patients, 176 of whom could be evaluated for efficacy. RESULTS Chlamydia trachomatis was cultured from 148 patients, 79 receiving azithromycin and 69 receiving doxycycline. Six patients receiving azithromycin had positive cultures on follow-up, four were known to have had sexual intercourse with infected partners. Fifty-one patients had gonorrhea; 28 were treated with azithromycin and 23 with doxycycline. Neisseria gonorrhoeae was eradicated from all patients except one receiving azithromycin. He denied sexual exposure during follow-up. Sixty patients were infected with Ureaplasma urealyticum, 35 were treated with azithromycin and 25 with doxycycline. Five patients in each group had positive cultures on follow up. Three patients receiving azithromycin and two receiving doxycycline were known to have had sexual exposure during follow-up. CONCLUSION A single dose of azithromycin showed similar effectiveness as a 7-day regimen of doxycycline.

Clinical and ecological characteristics of Vibrio vulnificus in the northeastern United States.

Multiple seawater sites in the northeastern United States, particularly Long Island Sound, and shellfish from Long Island Sound were sampled from April to November for 3 successive yr, 1983-1985. Hospitals in coastal and metropolitan areas of Connecticut were surveyed for the same 3-yr period, Vibrio vulnificus can be found in these waters during the summer months. The appearance of these virulent bacteria in both seawater and shellfish are a function of the water temperature; no V. vulnificus could be isolated until the temperature was approximately 17 degrees C. Although the risk of infection is small, as shown by isolation of this organism from patients, certain high-risk groups exist. Consumption of raw shell fish during the summer months should be discouraged in people with liver disease or patients on immunosuppressive therapy.

A five-year multicenter study of the susceptibility of the Bacteroides fragilis group isolates to cephalosporins, cephamins, penicillins, clindamycin, and metronidazole in the United States

Over 2800 clinical strains of the Bacteroides fragilis group were collected during a 5-year period from ten geographically separate sites and tested for their susceptibility to various antimicrobial agents using a broth microdilution method. Among the cephalosporins, ceftizoxime was the most active (13% resistance) and importantly exhibited relatively equal activity against both B. fragilis species and non-B. fragilis species. Cefotaxime exhibited similar activity with an overall resistance rate of 18%. Both ceftriaxone and cefoperazone were appreciably less active cephalosporins especially against non-B. fragilis species. With regard to cephamycins, cefoxitin (MIC90, 32 micrograms/ml) was more active than cefotetan (MIC90, > or = 256 micrograms/ml) and cefmetazole (MIC90, 64 micrograms/ml). Non-B. fragilis species were highly resistant to cefotetan and cefmetazole. Imipenem was highly active against all strains with the exception of four strains of B. fragilis. Ampicillin-sulbactam, amoxicillin-clavulanate, piperacillin-tazobactam, and cefoperazone-sulbactam were all highly active with resistance rates < 2%. No resistance was detected to metronidazole, whereas 14% of isolates were resistant to clindamycin. When compared with other studies, these findings underscore the wide variability in susceptibility patterns reported nationwide and the need to continue monitoring these patterns to aid in choosing the most active compounds for therapy.

Rapid detection of Chlamydia trachomatis by an enzyme immunoassay method

Chlamydia trachomatis has been shown to be a major cause of sexually transmitted diseases in the United States. An enzyme immunoassay (Abbot Laboratories) has been developed that detects chlamydial antigen directly in the urogenital specimens of patients. We have evaluated specimens from 1,074 patients belonging to one of three risk groups. Three swabs were collected from each patient--one each for Neisseria gonorrhoeae, chlamydia cell culture, and enzyme immunoassay. When compared with cell culture, the sensitivity and specificity of the enzyme immunoassay for symptomatic males and females attending a sexually transmitted disease clinic was 82% and 100%, and 91.3% and 95.0%, respectively. A moderate risk group, consisting of female patients seen at either urology or gynecology clinics for genitourinary symptoms was also evaluated. The sensitivity and specificity of the test on this group was 96% and 96.7%. A population of females at low risk were also screened for chlamydial infection. In this group, the sensitivity and specificity of the enzyme immunoassay was 89.3% and 93.2%, respectively. This rapid test is a highly specific and sensitive procedure for the detection of chlamydial antigen in genital specimens from high risk female patients as well as symptomatic males.

Synergism of Cefazolin-Gentamicin Against Enterococci

A miniaturized technique for detecting antibiotic synergy by using microliter volumes was perfected. With this microtiter serial dilution method, the effect of the previously untried combination of cefazolin and gentamicin on 10 strains of enterococci was evaluated. At clinically achievable concentrations, the combination of cefazolin and gentamicin was found to be synergistic against all 10 strains when the data were plotted in the form of an isobologram. These results were compared with the conventional method of detecting synergy in vitro, namely, the determination of the rate of killing of the microorganisms with the antibiotics, singly and in combination. Similar results were also observed. These findings indicate that the microtiter serial dilution technique is a useful method for the routine determination of drug synergy. Moreover, in a patient with penicillin hypersensitivity and enterococcal infection, the combination of cefazolin and gentamicin should be considered for possible therapy.

Development of an immunoglobulin M capture-based enzyme-linked immunosorbent assay for diagnosis of acute infections with Bartonella henselae.

ABSTRACT We describe the development of an immunoglobulin M-specific enzyme-linked immunosorbent assay for the detection of an early antibody response to Bartonella henselae, the causative agent of cat scratch disease, bacillary angiomatosis, and endocarditis. This assay discriminates between B. henselae-positive and -negative patient samples with sensitivity and specificity values of 100% and 97.1%, respectively.

Rapid screening of urine for significant bacteriuria by Gram stain, acridine orange stain, and the Autobac MTS system

Urine specimens submitted for microbiologic examination were screened for evidence of bacteriuria by three rapid methods: Gram staining, acridine orange staining, and the Autobac MTS system. The screening results were compared with those obtained by semiquantitative colony counts on agar plates. In this comparative study 1055 urine specimens were examined, of which 146 (13.8%) had colony counts of greater than or equal to 1 X 10(5)/ml. All three urine screening methods detected this level of bacteriuria at a sensitivity of 98% and a specificity of 55.2% (acridine orange), 66.0% (Gram stain), and 83.2% (Autobac), respectively. Of the 1055 urine specimens examined, 185 (17.5%) had colony counts of greater than or equal to 1 X 10(4)/ml, at which level the sensitivity of the three methods was 93% and the specificity was 56.7% (acridine orange), 68.0% (Gram stain), and 86.0% (Autobac), respectively. For any level of sensitivity, the Autobac urine screen was shown to be more specific than either the Gram stain or the acridine orange method. The acridine orange stain was the least specific urine screen, especially at the upper limits of sensitivity.

Clinical and Laboratory Evaluation of the Antibody-Coated Bacteria Test in Children

The antibody-coated bacteria test can distinguish upper from lower urinary tract infection. In this study 67 bacteriuric children were selected from meningomyelocele and urology clinics. There was close correlation between radiological evidence of upper tract changes and the presence of antibody-coated bacteria. There was a distinct lack of correlation between serum antibody titers to the infecting organism and antibody-coated bacteria. In vitro laboratory studies indicated that 1) antibody coating in the urine occurred immediately upon exposure of the infecting isolate to the urine of the patient, 2) only the homologous isolate was coated and 3) the pH range for antibody coating was wide (pH 4.0 to 9.0).

The Isolation of Rhodanese from Pseudomonas aeruginosa by Affinity Chromatography

Rhodanese (thiosulphate : cyanide sulphur-transferase; EC 2 . 8 . I . I) was originally ,described by Lang (1933). The enzyme catalyses the formation of thiocyanate from cyanide and thiosulphate according to the reaction : S20!+ CN-+ SCN+ SO:-. Rhodanese activity has been demonstrated in most mammalian tissues, with the greatest activity present in liver and kidney. The enzyme has been purified from liver (Horowitz & DeToma, 1970) and kidney (Westley & Green, 1959) as well as from several micro-organisms (Bowen, Butler & Happold, 1965; McChesney, 1958; Smith & Lascelles, 1966; Tabita, Silver & Lundgren,