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Biomedical subjects

W K Hadley

Publications and source records attributed to W K Hadley.

At least 73 records · Page 4Linked to original sources
PubMed1987

Flow cytometric analysis of Chlamydia trachomatis interaction with L cells.

Immunofluorescent staining and flow cytometric analysis have been investigated as means of studying the early stages of in vitro infection of Chlamydia trachomatis. The lymphogranuloma venereum strain of C. trachomatis was grown in vitro in L cells, fixed in p-formaldehyde, stained with fluorescein isothiocyanate (FITC)-conjugated monoclonal antibody to the chlamydial major outer membrane protein, and analyzed flow cytometrically. Infected cells stained 50-100 times more intensely than uninfected cells, and they could easily be discriminated by flow analysis. The number of infected cells and the fluorescence intensity of individual cells were proportional to the multiplicity of infection. The attachment of purified elementary bodies to L cells could be analyzed by immunofluorescence and flow cytometry. Cells exposed to 0.26 inclusion-forming units/cell could be discriminated from an unexposed population. Flow analysis of purified elementary bodies was possible after fluorescent staining with the aid of a laser-based cytometer and gating on low volume.

Animals↗
PubMed1987

Bacteriology of the marine environment: implications for clinical therapy.

Ocean water and tissue samples were obtained from a variety of sources with phylogenetic and geographic diversity. Purified bacterial colonies were isolated and identification procedures were performed. A total of 67 isolates were recovered. Thirty-eight isolates belonged to the genus Vibrio and included six species. Twenty-four non-fermentative bacteria and four Gram-positive isolates were recovered. Antibiotic susceptibility testing showed that while the non-fermentative marine bacteria generally were susceptible to the antibiotics tested, marine Vibrio species were relatively resistant to a wide variety of antimicrobials. Antibiotics effective against all species included imipenem, trimethoprim/sulfamethoxazole, and chloramphenicol. Further recommendations for treatment are based on sensitivity in culture. Some isolates failed to grow in the medium used for susceptibility testing. Because commercial test kits may not yield accurate identifications of bacteria, the acquisition of antimicrobial susceptibility data gains added importance.

Animals↗
PubMed1987

Bacteriology of the freshwater environment: implications for clinical therapy.

Water and animal tissue samples were obtained from sources in Tennessee, California, and Florida. Purified bacterial colonies were isolated and organisms identified. Fifty-eight isolates were recovered. Twenty-seven Gram-negative isolates were identified. Gram-positive organisms were of the coryneform group or Bacillus species. Antibiotic susceptibility testing showed that Aeromonas species were relatively resistant to a wide variety of antimicrobials, which included trimethoprim, cefazolin, and ampicillin. Antibiotics effective against more than 90% of Gram-negative isolates included ciprofloxacin, imipenem, ceftazidime, and trimethoprim-sulfamethoxazole. Freshwater Gram-positive organisms did not display any unexpected susceptibility features. Recommendation for treatment are based on sensitivity in culture and the potentially serious nature of infections caused by Aeromonas species.

Animals↗
PubMed1987

Therapeutic implications of inhibition versus killing of Mycobacterium avium complex by antimicrobial agents.

Patients with the acquired immune deficiency syndrome (AIDS) with disseminated Mycobacterium avium infection have responded poorly to treatment with rifabutine (Ansamycin) and clofazimine, in spite of the good in vitro response of M. avium to these antimicrobial agents. We compared the ability of these and other antimicrobial agents to kill versus the ability to inhibit the growth of strains of the M. avium complex isolated from patients with AIDS. Killing curve experiments showed that the concentrations of rifabutine and clofazimine needed to kill two log units of M. avium are at least 32 times greater than the concentrations needed to inhibit growth. Little or no killing occurred at concentrations of these antimicrobial agents that are achievable in serum. In contrast, five of seven strains tested were killed by ciprofloxacin at concentrations that can be achieved in serum. Ciprofloxacin should be studied further for possible use in the treatment of M. avium infections.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Broth microdilution testing of susceptibilities to 30 antimicrobial agents of Mycobacterium avium strains from patients with acquired immune deficiency syndrome.

A total of 31 strains of Mycobacterium avium complex isolated from patients with acquired immune deficiency syndrome were tested for susceptibility to 30 antimicrobial agents by using microdilution trays containing dried antimicrobial agents. MICs were determined over a period of 7 days of growth in a broth medium (7HSF) that is equivalent to 7H11 agar. MICs obtained by this method showed good agreement with MICs determined by the agar dilution method. Strains could be divided into two groups by their antimicrobial susceptibility patterns. All group 1 strains (8 of the 31 strains tested) were at least moderately susceptible to inhibition by a variety of beta-lactam antimicrobial agents, including amoxicillin-clavulanic acid and cefmenoxime. Group 2 strains (23 of 31) were susceptible only to amikacin (22 of 23 strains). All 31 strains were resistant to oxacillin, clindamycin, erythromycin, tetracycline, chloramphenicol, vancomycin, nitrofurantoin, and aztreonam at the highest concentration of antimicrobial agent present in the microdilution trays. The addition of Tween 80 to 7HSF broth increased the susceptibility of M. avium complex to many of the antimicrobial agents tested. Killing of M. avium complex (i.e., less than or equal to 1% survival after 7 days) was found to vary for different strains and antimicrobial agents. Killing of some strains by amoxicillin-clavulanic acid, carbenicillin, azlocillin, cefmenoxime, cefotaxime, amikacin, and ampicillin occurred at concentrations of antimicrobial agent that are achievable in serum. Further studies are needed to determine whether any of these antimicrobial agents has activity against M. avium complex cells that have been ingested by macrophages.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Successive bacteremias with "Campylobacter cinaedi" and "Campylobacter fennelliae" in a bisexual male.

A bisexual human immunodeficiency virus-seropositive male had successive bacteremias with "Campylobacter cinaedi" and "Campylobacter fennelliae." Because final identification of both isolates was not completed until 1 month after the last admission of the patient, a novel and nonstandardized antimicrobial susceptibility testing method was useful in guiding timely antimicrobial therapy.

AIDS-Related Complex↗
PubMed1986

Occurrence of clindamycin-resistant anaerobic bacteria isolated from cultures taken following clindamycin therapy.

MICs of clindamycin were determined by the agar dilution method against anaerobic organisms isolated from endometrial cultures in women with pelvic soft tissue infections. Cultures were obtained from 100 women both before and after clindamycin therapy, from 107 women before therapy with clindamycin or another antimicrobial agent or after treatment with an antimicrobial agent other than clindamycin, and from 9 women 1 to 9 weeks after they were discharged from the hospital following clindamycin therapy. Only 5 (0.7%) of 685 isolates tested from women who had not received clindamycin therapy were resistant to clindamycin. From the 100 cultures taken immediately after clindamycin therapy, 57 anaerobic bacteria were isolated from 28 cultures. Of the 40 anaerobic organisms for which MICs of clindamycin were determined, 25 (62.5%) were resistant to clindamycin (MIC greater than or equal to 8 micrograms/ml). The most common organisms isolated after therapy were the anaerobic gram-positive cocci (of which 32 isolates were discovered); of 28 coccal isolates tested, 64% were clindamycin resistant. Four of seven (57%) of the Bacteroides isolates tested, one unidentified gram-positive nonsporing rod, one unidentified gram-negative coccus, and one Mobiluncus sp. were also clindamycin resistant. Of 18 anaerobic isolates from the nine cultures taken 1 to 9 weeks after hospital discharge, 55% were resistant to clindamycin. The clinical significance of these findings is unknown since all patients recovered without incident and remained well. However, the data suggest that physicians need to be aware that patients with recent exposure to clindamycin may have clindamycin-resistant anaerobic organisms in a current infection. This may prevent the infection from responding to clindamycin treatment.

Bacteria, Anaerobic↗
PubMed1986

Effect of storage temperature and pH on the stability of antimicrobial agents in MIC trays.

Twelve antimicrobial agents, ampicillin, aztreonam, cefamandole, cefazolin, cefonicid, ceforanide, ceftazidime, ceftizoxime, ceftriaxone, cefuroxime, ciprofloxacin, and norfloxacin, were prepared at pH 6.80 and 7.31 in microdilution trays for storage at 4, -10, -25, and -70 degrees C and for weekly susceptibility testing. All 12 drugs had stable biological activity when stored at -70 degrees C for 1 year. All but ampicillin and aztreonam were stable at -25 degrees C. Storage at -10 degrees C was least satisfactory. Desiccation occurred at 4 degrees C, but short-term storage at this temperature is possible since the antimicrobial agents are stable for up to several months.

Anti-Bacterial Agents↗
PubMed1986

Clinical trial comparing bacitracin with Strep-A-Chek for accuracy and turnaround time in the presumptive identification of Streptococcus pyogenes.

In a clinical trial, Strep-A-Chek (a 10-min chromogenic test) was compared with the bacitracin disk susceptibility test for accuracy and turnaround time in the presumptive identification of Streptococcus pyogenes. Among 461 isolates of beta-hemolytic streptococci (344 throat isolates and 117 isolates from other sites), 303 group A S. pyogenes isolates were found. The sensitivities of the Strep-A-Chek and bacitracin tests were high (96.4 and 100%, respectively), but the bacitracin test had a lower specificity (84.2%) than the Strep-A-Chek test (98.7%). The predictive values for positive and negative test results were 99.3 and 93.4%, respectively, for Strep-A-Chek and 92.4 and 100%, respectively, for bacitracin. Strep-A-Chek correctly identified all isolates upon repeat testing. All bacitracin tests were performed on subcultures of isolates from the primary plate. Strep-A-Chek testing was performed on colonies from the primary plate when isolated colonies were available. This shortened the turnaround time for Strep-A-Chek compared with bacitracin by at least 24 h on nearly one-half (45%) of the isolates. A peripheral finding of this study was that sulfamethoxazole-trimethoprim blood agar offered no advantage over conventional blood agar with regard to the number of false-positive bacitracin tests obtained from each medium.

Bacitracin↗
PubMed1986

The usefulness of induced sputum in the diagnosis of Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome.

Thirty-two patients with or suspected of having the acquired immunodeficiency syndrome were evaluated for opportunistic lung infection using examination of sputum induced by inhalation of 3% saline. The specimens obtained were stained with Giemsa stain and examined for Pneumocystis carinii. Smears of sputum were also appropriately stained and examined for acid-fast organisms and fungi, as well as cultured for these organisms. Patients whose sputum did not contain P. carinii had bronchoscopy within 24 h of sputum induction. Twenty-five of the 32 patients were ultimately determined to have P. carinii pneumonia. Of these, 14 were detected by examination of sputum (sensitivity, 56%). Of 18 patients whose sputum did not contain P. carinii, 11 had the organism detected in specimens obtained by bronchoscopy (negative predictive value, 39%). There were no clinical features that identified patients more likely to have a positive sputum examination. No additional treatable lung pathogens appeared to be missed by sputum examination. In this select population, examination of induced sputum establishes the diagnosis of P. carinii pneumonia in a significant proportion of patients, thereby decreasing the need for more invasive procedures.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Sulbactam/ampicillin versus metronidazole/gentamicin in the treatment of severe pelvic infections.

The clinical efficacy and safety of sulbactam/ampicillin versus metronidazole/gentamicin were compared in 39 patients with severe pelvic infections. 30 patients had severe acute pelvic inflammatory disease with peritonitis, 3 tubo-ovarian abscesses, 4 endomyometritis, and 2 posthysterectomy pelvic cellulitis. Aerobic and anaerobic cultures from the sites of infection yielded 259 micro-organisms from 38 patients; an average of 6.8 bacteria per infection (3.9 anaerobes and 2.9 aerobes). The most frequent isolates were Bacteroides spp. (21), B. bivius (13), B. disiens (8), Fusobacterium spp. (9), Peptostreptococcus anaerobius (15), P. asaccharolyticus (8), anaerobic Gram-positive cocci (17), Gardnerella vaginalis (24), Neisseria gonorrhoeae (14), alpha-haemolytic streptococci (6) and Escherichia coli (3). Clinical cure was noted in 19 of 20 patients treated with sulbactam/ampicillin and 16 of 19 treated with metronidazole/gentamicin. The sulbactam/ampicillin failure was a patient with pelvic inflammatory disease with a positive Chlamydia trachomatis culture who required antichlamydial therapy. The metronidazole/gentamicin failures included a patient with a tubo-ovarian abscess requiring surgical drainage and 2 patients with pelvic inflammatory disease requiring antichlamydial treatment. No adverse haematological, renal, or hepatic effects were noted with either regimen.

Ampicillin↗
PubMed1986

Trimethoprim-sulfamethoxazole or pentamidine for Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome. A prospective randomized trial.

Forty patients with the acquired immunodeficiency syndrome (AIDS) and their first episodes of Pneumocystis carinii pneumonia were assigned at random to receive either trimethoprim-sulfamethoxazole or pentamidine isethionate. The two groups did not differ significantly in the severity of pulmonary or systemic processes at enrollment. Five patients treated initially with trimethoprim-sulfamethoxazole and one patient treated initially with pentamidine died during the 21-day treatment period (p = 0.09, Fisher's exact test). No significant differences were seen between groups in rates of improvement, pulmonary function tests, or 67Ga uptake by the lungs in the survivors at completion of therapy. Adverse reactions necessitated changing from the initial drug in 10 patients in the trimethoprim-sulfamethoxazole group and 11 in the pentamidine group. Minor reactions occurred in all patients. In patients with AIDS, trimethoprim-sulfamethoxazole and pentamidine do not have statistically significant differences in efficacy or frequency of adverse reactions.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Antibody to the retrovirus associated with the acquired immunodeficiency syndrome (AIDS). Presence in presumably healthy San Franciscans who died unexpectedly.

We performed autopsies and serologic tests in 189 subjects (152 men and 37 women) between 20 and 50 years of age with no history of immunosuppression who died unexpectedly and whose bodies were referred to the San Francisco coroner's office. Forty-eight of the 88 single men for whom addresses were available lived in areas of the city with a high incidence of the acquired immunodeficiency syndrome (AIDS). In addition, 36 of the subjects (30 men) were intravenous drug abusers. Antibody to the retrovirus associated with AIDS was present in 23 (18%) of the 121 subjects whose sera were tested. However, neither pathologic nor laboratory manifestations of AIDS were present in any of the 189 subjects who underwent autopsy. These results suggest that antibody to the retrovirus is common but subclinical manifestations of AIDS are uncommon in San Francisco, a city where the incidence of clinical AIDS is high.

Acquired Immunodeficiency Syndrome↗
PubMed1985

In vitro adherence of Lactobacillus species to vaginal epithelial cells.

Because of the reported use of yogurt douches for the treatment of vaginitis, the adherence of Lactobacillus species to normal human vaginal epithelial cells was tested by in vitro methods. L. acidophilus and L. bulgaricus isolated from three commercial yogurts were compared to L. acidophilus, L. fermentum, L. cellobiosus, and L. casei isolated from clinical specimens and from American Type Culture Collection cultures. L. acidophilus isolated from Lactinex tablets was also tested. No significant difference was found among the 19 clinical isolates, the American Type Culture Collection cultures, and the Lactinex isolate, but all showed significantly higher (p less than 0.01) adherence than any Lactobacillus isolated from yogurt. The presence of Gardnerella vaginalis, which adheres strongly to vaginal epithelial cells, was found to interfere with the adherence of lactobacilli from all sources studied.

Adhesiveness↗
PubMed1985

Effects of exopolysaccharide production by viridans streptococci on penicillin therapy of experimental endocarditis.

The influence of exopolysaccharide production by viridans streptococci on penicillin therapy of endocarditis was studied in rabbits with experimental aortic-valve endocarditis. Animals were first infected with penicillin-susceptible streptococci known to produce varying amounts of exopolysaccharide in cardiac vegetations. Treatment with procaine penicillin, 300,000 U every 12 hr, was begun one to two days after infection. After five days of therapy, animals infected with Streptococcus sanguis II and Streptococcus morbillorum, both vigorous exopolysaccharide producers, continued to have infected vegetations, while animals infected with Streptococcus salivarius and a different Streptococcus sanguis II, both deficient in exopolysaccharide production, had sterile vegetations. These findings indicate that failure to eradicate streptococci from vegetations correlates with exopolysaccharide production and that this property may be important in determining outcome of therapy.

Animals↗
PubMed1985

In vitro activity of cefbuperazone and other antimicrobial agents against isolates from the female genital tract.

Cefbuperazone (BMY 25182), a new cephamycin, showed activity similar to those of moxalactam and other cephalosporin-cephamycins against aerobic and anaerobic bacteria from female genital tract infections. MICs of the antimicrobial agents were less than or equal to 16 micrograms/ml for greater than 97% of organisms tested. All of the anaerobic bacteria tested were susceptible to clindamycin, metronidazole, and chloramphenicol.

Anti-Bacterial Agents↗