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Biomedical subjects

M C Parekh

Publications and source records attributed to M C Parekh.

At least 19 recordsLinked to original sources
PubMed1995

In vitro activity of a new fluoroquinolone, CP-99,219, against strains of Neisseria gonorrhoeae.

The susceptibilities of 216 strains of Neisseria gonorrhoeae to a new fluoroquinolone, CP-99,219 were determined. For strains for which the MICs of ciprofloxacin were < or = 0.06 microgram/ml, the MICs at which 90% of the isolates are inhibited (MIC90s) of CP-99,219, ciprofloxacin, and ofloxacin were 0.008, 0.015, and 0.03 microgram/ml, respectively. For strains for which the MICs of ciprofloxacin were 0.125 to 0.5 microgram/ml, the MIC90s of CP-99,219, ciprofloxacin, and ofloxacin were 0.06, 0.25, and 0.5 microgram/ml, respectively. For strains for which the MICs of ciprofloxacin and ofloxacin were 2.0 micrograms/ml, the MIC of CP-99,219 was 0.25 microgram/ml.

Anti-Infective Agents↗
PubMed1994

Persistence of Neisseria gonorrhoeae strains with decreased susceptibilities to ciprofloxacin and ofloxacin in Cleveland, Ohio, from 1992 through 1993.

Twenty-five isolates of beta-lactamase-negative strains of Neisseria gonorrhoeae exhibiting decreased susceptibilities to ciprofloxacin (MIC, > or = 0.125 microgram/ml) were isolated from men with uncomplicated gonococcal urethritis in Cleveland, Ohio, from January 1992 through June 1993. The strains belonged to three auxotype-serovar classes: Pro-IB-1 (2 isolates), Pro-IB-2 (21 isolates), and Pro-IB-3 (2 isolates). MICs for strains were in the intermediate or resistant categories for penicillin, the intermediate or susceptible categories for tetracycline (with the exception of one strain that had acquired the 25.2-MDa TetM-containing plasmid) and cefoxitin, and the susceptible categories for ceftriaxone and cefixime (MICs, < or = 0.25 microgram/ml) and spectinomycin (MIC, < or = 256 micrograms/ml). MICs for strains were also in the susceptible category for ofloxacin (MIC, 0.25 microgram/ml) and in categories higher than susceptible for ciprofloxacin (MICs, 0.125 to 0.25 microgram/ml) and ofloxacin (MIC, 0.5 microgram/ml). The diameters of zones of inhibition for these strains ranged from 31 to 39 mm for ciprofloxacin to 28 to 35 mm for ofloxacin. The persistence of these strains over an 18-month period supports the need for routine sentinel surveillance and monitoring of gonococcal isolates, particularly posttreatment isolates, for resistance to quinolones when these agents are used for the primary therapy of uncomplicated gonorrhea.

Ciprofloxacin↗
PubMed1994

Emerging in vitro resistance to quinolones in penicillinase-producing Neisseria gonorrhoeae strains in Hawaii.

The susceptibilities of 37 penicillinase-producing strains of Neisseria gonorrhoeae (PPNG), isolated in Hawaii from December 1991 through January 1994, were determined to ciprofloxacin and ofloxacin, fluoroquinolone agents currently recommended by the Centers for Disease Control and Prevention as alternative regimens for the treatment of uncomplicated gonorrhea. Nine isolates (24.3%) exhibited decreased susceptibilities (MICs, > or = 0.06 microgram/ml) to ciprofloxacin and ofloxacin. Ciprofloxacin MICs for three isolates (8.1%) were 2.0 micrograms/ml; these isolates belonged to the auxotype/serovar class Pro/IB-7 and possessed the 3.2-MDa beta-lactamase and the 24.5-MDa conjugative plasmids. Six strains for which ciprofloxacin MICs were 0.06 to 0.125 microgram/ml belonged to a variety of gonococcal phenotypes. Strains for which ciprofloxacin MICs were 2.0 micrograms/ml were isolated from persons who had traveled to, or were sexual contacts of persons who had recently traveled to, Southeast Asia. Persons infected with these isolates had been treated with ceftriaxone (250 mg intramuscularly, single dose); therefore, none of these cases were associated with clinical failure following the use of fluoroquinolone therapy. Further studies are needed to confirm the clinical and public health significance of increased in vitro resistance to ciprofloxacin and ofloxacin in N. gonorrhoeae.

Ciprofloxacin↗
PubMedDate not supplied

Changes in the prevalence of auxotypes of Neisseria gonorrhoeae among black and white patients attending a clinic for sexually transmitted diseases.

Before 1978, isolates of Neisseria gonorrhoeae from white patients attending a venereal disease clinic were more susceptible to penicillin G than were isolates from black patients, because the whites were more frequently infected with the Arg- Hyx- Ura- auxotype that was highly susceptible to penicillin. Recent isolates from the same clinic show a change both in the auxotypes and in the penicillin susceptibility of N. gonorrhoeae infecting the two patient groups. Of 211 isolates studied in 1978, the four most common auxotypes were, in decreasing frequency: Pro-, nonrequiring, Arg- Hyx- Ura- and Arg-. In the present study of 265 isolates, the order of frequency was nonrequiring; Pro-; Pro- Arg-(Orn*) Ura-; and Arg- Hyx- Ura-. The Pro- Arg-(Orn*) Ura- auxotype was new to the clinic and was significantly more frequent in white than in black patients and significantly more resistant to penicillin than were gonococci of the remaining auxotypes. With the appearance of the Pro- Arg-(Orn*) Ura- auxotype among white patients, there was no significant difference in the susceptibility to penicillin of isolates of N. gonorrhoeae from the two groups of patients.

Black or African American↗
PubMedDate not supplied

Association of auxotypes of Neisseria gonorrhoeae and susceptibility to penicillin G, spectinomycin, tetracycline, cefaclor, cefoxitin, and moxalactam.

Isolates of Neisseria gonorrhoeae from 304 patients attending a venereal disease clinic were examined by a plate dilution method for their susceptibility to six antibiotics: penicillin G, spectinomycin, tetracycline, cefaclor, cefoxitin, and moxalactam. The isolates were also characterized by gonococcal auxotyping. The most frequent auxotypes were Nonrequiring, 58%; Pro-, 14%; Pro- Arg (Orn*) Ura-, 14%; Arg- Hyx- Ura-, 6%; and a miscellaneous group consisting of 8% of the isolates. If the entire group of isolates were examined, moxalactam was the most active of the antibiotics; 94% of the isolates were inhibited by less than or equal to 0.25 microgram/ml. The Pro- Arg (Orn*) Ura- isolates were relatively resistant to penicillin G and cefoxitin. The Arg- Hyx- Ura- group of isolates was the most susceptible of the auxotypes to all of the antibiotics except spectinomycin. The uncommon auxotype Arg (Orn*) Ura- has a requirement for arginine that is satisfied by citrulline but not by ornithine. The results of the present study indicate that the nutritional requirements of gonococci may be associated with their response to certain antibiotics.

Amino Acids↗
PubMedDate not supplied

Attachment of two auxotypes of Neisseria gonorrhoeae to cells of donors of African, European, and Indian descent.

Gonococci of the Arg-, Hyx-, Ura- auxotype are isolated most commonly from white patients and seldom from black patients. Five gonococcal isolates of the Arg-, Hyx-, Ura- auxotype and five of the Pro- auxotype were tested for their ability to attach to buccal epithelial cells or to attach or be ingested by polymorphonuclear leukocytes taken from two individuals each of three different racial backgrounds: European-American (caucasian), black American, and Indian from India. Despite the differences in race of the six individuals, there were no differences in the attachment or ingestion of the two gonococcal auxotypes to the two different cell types. The study does not explain why the Arg-, Hyx-, Ura- auxotype is isolated more frequently from whites.

Adult↗
PubMedDate not supplied

Incidence of disseminated gonococcal infection correlated with the presence of AHU auxotype of Neisseria gonorrhoeae in a community.

Strains of Neisseria gonorrhoeae requiring arginine, hypoxanthine, and uracil (AHU) may cause disseminated gonococcal infection (DGI). A significant epidemiologic association was noted between the incidence of disseminated gonococcal infection and the presence of gonococci of the AHU auxotype in the community over a nine-year period. Thirty-nine patients with DGI were identified from hospital records of January 1974-December 1982. During this interval, gonococcal isolates from patients in the community were collected at a venereal disease clinic and a hospital emergency room. The incidence of patients hospitalized for DGI dropped significantly after 1978. The year of highest incidence of DGI was 1977, when there were 429 cases of DGI per 100,000 cases of uncomplicated gonorrhea; the incidence of gonococcal isolates of the AHU auxotype in that year was 26.3%. In contrast, this auxotype accounted for only 4.6% of gonococcal isolates in 1980, when the incidence of DGI had decreased to 58 cases per 100,000 cases of uncomplicated gonorrhea. When DGI and gonococci of the AHU auxotype from the community were ranked for incidence by year, a significant correlation between the two was found (P less than .001). Thus the incidence of patients with DGI in the hospital reflected the presence of gonococci of the AHU auxotype in the community.

Adolescent↗
PubMedDate not supplied

Susceptibility of different auxotypes of Neisseria gonorrhoeae to norfloxacin, cefotaxime, cefuroxime, and erythromycin.

Isolates of Neisseria gonorrhoeae from 150 patients attending a venereal disease clinic were examined for their susceptibility to four antibiotics (norfloxacin, cefotaxime, cefuroxime, and erythromycin) by a plate-dilution method. The isolates were also characterized by gonococcal auxotyping. The most frequent auxotypes were nonrequiring, 50%; Pro-, 16.7%; Pro-, Arg-, (Orn*), Ura-, 10.7%; Arg-, Hyx-, Ura-, 12.7%; and a miscellaneous group consisting of 10% of the isolates. Norfloxacin was the most active of the antibiotics; all of the isolates were inhibited by less than or equal to 0.06 microgram/ml. The Arg-, Hyx-, Ura- group of isolates was the most susceptible of the auxotypes to antibiotics. In the present study N. gonorrhoeae of the Arg-, Hyx-, Ura- auxotype fell into two groups with respect to erythromycin, one highly susceptible and one less susceptible. The results of the present study provide further evidence that the nutritional requirements of gonococci are associated with their response to certain antibiotics.

Anti-Bacterial Agents↗
PubMedDate not supplied

Chemotaxis of polymorphonuclear leukocytes from donors of different races toward Neisseria gonorrhoeae of three different auxotypes.

Urethral gonorrhea is typified by the presence of large numbers of polymorphonuclear leukocytes, which are presumably attracted to the urethra by an as yet uncharacterized chemotaxin. Culture supernatants from three different auxotypes of Neisseria gonorrhoeae, one requiring arginine, hypoxanthine, and uracil (Arg-,Hyx-,Ura-), one requiring proline, arginine (not satisfied by ornithine), and uracil (Pro-,Arg-[Orn*],Ura-), and one requiring proline (Pro-), were tested for their chemotactic activity against leukocytes from men of two racial groups, white and black. These auxotypes were chosen because the Pro- auxotype is isolated more frequently from black patients, and the Arg-,Hyx-,Ura- and the Pro-,Arg-(Orn*),Ura- auxotypes are isolated more frequently from white patients. Chemotaxis was tested in blind-well chambers in the absence of complement; membranes with a pore size of 3 microns were used. The culture supernatants of the Pro- auxotype were the most chemotactic, while those of the Arg-,Hyx-,Ura- were the least chemotactic when analyzed by a three-way analysis of variance: F = 22.83, df = 2.6, P less than .001. There were no differences in migration with respect to the race of the donor. Gonococcal culture supernatants did not require complement for chemotaxis.

Black People↗