non-PPNG Isolates Research Articles

Antimicrobial resistance in gonococci isolated from patients and from commercial sex workers in Harare, Zimbabwe

The objective is to compare antibiotic resistance amongst gonococci isolated from different patient groups in Harare, Zimbabwe. Antimicrobial susceptibilities of Neisseria. gonorrhoeae were determined by disc sensitivity tests. The MICs for penicillin, kanamycin, ceftriaxone, norfloxacin and ciprofloxacin were determined using E-test strips. There were 147 isolates from symptomatic men, 47 isolates from symptomatic women, 29 isolates from asymptomatic women and 41 isolates from female commercial sex workers. A total of 119 (45%) isolates were PPNG and 23 (16%) non-PPNG isolates had a penicillin MIC>0.64 mg/l. Over 90% of isolates were resistant to TMP/SMX and 16% were resistant to tetracycline. Resistance was uncommon against kanamycin (6%), erythromycin (2%) or ceftriaxone (<1%). For kanamycin, the MIC 90 was 32 mg/l, for ceftriaxone the MIC 90 was <0.032 mg/l for non-PPNG and <0.064 mg/l for PPNG. For norfloxacin and ciprofloxacin the MIC 90 was <0.064 mg/l for both PPNG and non-PPNG. Isolates from the commercial sex workers showed a significantly increased prevalence of PPNG, of penicillin-tolerant non-PPNG and of tetracycline resistance. Four of the 41 isolates from sex workers showed multiple resistance (to penicillin, TMP/SMX, tetracycline and kanamycin) compared to 1/223 isolates from other groups (OR=24.0). Antimicrobial resistance is common amongst gonococci in Harare, especially with isolates from commercial sex workers. In order for STD treatment to be implemented as an effective strategy in HIV control, continued monitoring of resistance patterns is essential.

Antimicrobial susceptibility and types of Neisseria gonorrhoeae in Greece. Data for the period 1990 to 1993.

Surveillance of the rapidly changing patterns of antimicrobial resistance of Neisseria gonorrhoeae is imperative for monitoring gonococcal infection. To describe the types and the antimicrobial susceptibility profile of a representative samples of gonococci isolated in Greece between 1990 and 1993. The antimicrobial susceptibilities, serovar/auxotypes classes, and plasmid contents of 263 consecutive isolates of N. gonorrhoeae, recovered from cases of male gonococcal urethritis, were determined. Penicillinase-producing N. gonorrhoeae (PPNG) were isolated at a rate of 6.1% and were mostly from imported cases of infection. Six (2.3%) of the isolates (one PPNG and five non-PPNG) were highly resistant to tetracycline, and one PPNG strain was resistant to norfloxacin and ciprofloxacin. Strains with chromosomal resistance to penicillin, tetracycline, erythromycin, and chloramphenicol accounted for 18.5%, 12.5%, 19%, and 16% of the isolates, respectively; much higher proportions of strains were intermediately susceptible to these antibiotics. Spectinomycin and cefotaxime were active against all gonococci studied. A shift to IB serovars and to sporadic types of strains was noted from previous years among the non-PPNG isolates. This is compatible with the marked increase in the rate of imported cases of infection caused by n on-PPNG strains. The emergence of high-level resistance to tetracycline and resistance to fluoroquinolones was ascertained. At the present, however, the main problem with gonococcal resistance in Greece seems to ensue from the increasing rates of chromosomally resistant strains. Moreover, the increasing frequency of imported gonococci underlines the necessity for continuous epidemiologic surveillance.

A one-year survey of Neisseria gonorrhoeae isolated from patients attending an east London genitourinary medicine clinic: antibiotic susceptibility patterns and patients' characteristics.

To collect epidemiological data on gonococcal infection in an east London genitourinary medicine (GUM) clinic; to perform antibiotic susceptibility testing on Neisseria gonorrhoeae isolates and relate results to patient data; to assess the efficacy of current first-line antibiotic therapy for treating gonorrhoea. Gonococcal isolates were collected from 113 patients attending the GUM clinic at Newham General Hospital over a one year period. Isolates (104) were tested for susceptibility to various antibiotics. Plasmid profiles were obtained for penicillinase producing gonococci (PPNG) and isolates exhibiting high-level tetracycline resistance (TRNG). Epidemiological information was collected from clinic attenders by routine note-taking. PPNG (16) accounted for 15% of isolates tested, only three being acquired outside the United Kingdom (U.K.). Plasmid typing showed three types of beta-lactamase-encoding plasmids were represented (2.9 MDa, 3.2 MDa and 4.4 MDa). Amongst the non-PPNG isolates, high-level chromosomal resistance to penicillin (CMRNG) was found in 3.5%, intermediate resistance in 57.5% and full susceptibility in 39%. One isolate showed decreased susceptibility to ciprofloxacin (MIC = 0.06 mg/l). Three PPNG isolates also possessed a 25.2 MDa plasmid and expressed high-level tetracycline resistance encoded by tetM. All isolates were susceptible to cefixime, cefotaxime, azithromycin and spectinomycin. Most gonorrhoea (90%) was seen in local residents. The male:female case ratio was 2:1 with homosexually-acquired gonorrhoea accounting for only 3.5% of the total. Most patients (96%) had acquired gonorrhoea in the U.K.. A past history of gonorrhoea was more frequent in male patients. Concurrent chlamydial infection was seen in 31% females and 16% males. The high PPNG rate supports a previous decision to change first-line therapy from amoxycillin with probenecid to ciprofloxacin. There was no evidence of clinical treatment failure with ciprofloxacin. Cefixime, cefotaxime, azithromycin and spectinomycin all appear to be suitable alternative therapies. Acquisition of gonorrhoea abroad was associated with isolates exhibiting penicillin resistance but such isolates were also obtained from patients infected locally and without a history of foreign travel.

Effectiveness of norfloxacin and ofloxacin for treatment of gonorrhoea and decrease of in vitro susceptibility to quinolones over time in Rwanda.

To study the effectiveness of single-dose norfloxacin and ofloxacin in the treatment of gonococcal urethritis in men, and to monitor in vitro antimicrobial susceptibility to these antibiotics over time. Centre Médico-Social de Bilyogo, Kigali, Rwanda. The only clinic in Rwanda using quinolones for the treatment of gonorrhoea. As part of a monitoring programme, men with gonococcal urethritis were evaluated after treatment with norfloxacin (800 mg) in 1986 and 1987, and after treatment with ofloxacin (400 mg) in 1989. Neisseria gonorrhoeae was eradicated from the urethra from 96.0% (189/197) and from 97.1% (166/171) men treated with norfloxacin and ofloxacin, respectively. Overall 38.2% of the pretreatment isolates produced penicillinase (PPNG isolates) and 20.4% (44/216) of the tested non-PPNG isolates were chromosomally resistant to penicillin (MIC > or = 2.0 mg/l). Resistance to tetracycline and thiamphenicol was common in both PPNG and non-PPNG and increased considerably in 1989. All isolates were susceptible to kanamycin, spectinomycin, ceftiaxone, norfloxacin, ofloxacin and ciprofloxacin. However, a higher number of isolates recovered in 1989 showed decreased susceptibility to the quinolones. Treatment failure occurred more often in subjects with isolates having MIC values > or = 0.06 mg/L of norfloxacin (p = 0.006). Seven out of 13 patients who did not respond to therapy had no signs nor symptoms of urethritis. Quinolone antibiotics are now indicated as a first line treatment of gonorrhoea in countries with a problem of antimicrobial multiresistance. However, antimicrobial susceptibility to the quinolones may decrease rapidly, and close monitoring of the in vitro susceptibility of N gonorrhoeae and the clinical effectiveness of the antibiotics is imperative.

Neisseria gonorrhoeae in Athens, Greece

The incidence of gonorrhoea cases diagnosed in a major venereal hospital of Athens, Greece, was markedly reduced between 1986 and 1989. All 182 gonococcal isolates found during this period were epidemiologically classified into Sero-/Auxo-/Plasmid content (S/A/Pc) types. Susceptibility to six antimicrobials was also determined. Penicillinase-producing Neisseria gonorrhoeae (PPNG) strains were isolated in an increased frequency of 7.7% and a striking shift in their distribution into S/A/Pc types was noted from previous years. The isolates exhibited wide heterogeneity of type: none of the 14 PPNG strains was identical, while the 168 non-PPNG strains were distributed into 64 S/A/Pc types. Fifty-seven percent (57%) of the PPNG and 86% of the non-PPNG isolates were of the WII/III serogroup. Chromosomally mediated resistance to penicillin, ampicillin, or both was exhibited by 14% of the non-PPNG isolates. Greater frequency of reduced susceptibility to cefotaxime, tetracycline, and chloramphenicol was also found among PPNG and non-PPNG strains, mostly of the WII/III serogroup. Twelve percent (12%) of the non-PPNG and 57% of the PPNG strains had multiple patterns of resistance, involving 2 to 4 antimicrobials of different class lines.

Gonorrhoea and Urogenital Chlamydial Infection in Female Prostitutes in Tegucigalpa, Honduras

The prevalence of gonorrhoea and urogenital chlamydial infection was investigated in female prostitutes in Tegucigalpa, Honduras. Epidemiological data were recorded according to a standardized questionnaire. The median age of the prostitutes was 27 years and the median period of prostitution was 2-4 years. Most of the women (91%) had no occupation other than prostitution and 57% of them had not even completed primary school. In 233 cases when both gonococcal culture and chlamydial antigen detection with a commercial EIA kit were performed the prevalence of gonorrhoea was 25% (59) and that of chlamydial infection 31% (72). Both diseases were recorded in 9%. The women who had been prostitutes for 2 years or longer had gonorrhoea (P less than 0.01) or chlamydial infection (P less than 0.05) less frequently than those who had practised prostitution for a shorter time period. Among 70 different gonococcal isolates from 241 prostitutes, 40 (57%) belonged to serogroup W II/III. Most (83%) of the 30 W I isolates were beta-lactamase producing (PPNG) like 42% of the W II/III isolates. All non-PPNG isolates, except one had decreased susceptibility to benzylpenicillin (MIC greater than or equal to 0.125 mg/l) and all isolates were susceptible to spectinomycin. Four out of five isolates from the throat were PPNG and the fifth had a benzylpenicillin MIC of 0.5-2.0 mg/l.

Molecular epidemiology and novel combinations of auxotype, serovar, and plasmid content in tetracycline-resistant Neisseria gonorrhoeae isolated in Canada

Between October 1987 and June 1989, 84 isolates of Neisseria gonorrhoeae carrying the TetM resistance determinant (TRNG) were received at the Laboratory Centre for Disease Control, Ottawa, from six Canadian provinces and were characterized into classes based on auxotype, serovar and plasmid content. One-fifth (17/84) of the TRNG were also penicillinase producing (PPNG). The PPNG-TRNG isolates comprised six classes based on auxotype, serovar, and plasmid content. Most (16/17) PPNG-TRNG carried 3.2-MDa beta-lactamase plasmids and the 25.2-MDa TetM-containing plasmid. We report, for the first time, the association of a 4.5-MDa beta-lactamase plasmid with the 25.2-MDa plasmid in a clinical TRNG isolate. Non-PPNG TRNG isolates comprised 11 classes based on auxotype, serovar, and plasmid content, including two previously unreported auxotype-serovar classes, P/IB-26 and P/IB-20.

Characterisation by plasmid profiles, serogroups, and auxotypes of Neisseria gonorrhoeae from Harare, Zimbabwe.

(ABSTRACTOne hundred and fifty five strains of Neisseria gonorrhoeae were regrown from 216 freeze dried cultures originally isolated in Zimbabwe. The gonococci were from men (61 strains) and women (39 strains) attending a referral sexually transmitted diseases (STD) clinic, from women presenting for delivery at hospital with signs of sepsis (22 strains) or with an asymptomatic infection (16 strains), and from babies with ophthalmia neonatorum (17 strains). Seventy five of the 100 isolates from STD clinic patients and 29 of the 55 isolates from hospital patients were penicillinase producing N gonorrhoeae (PPNG). Two thirds of all PPNG strains contained the 24.5 megadalton conjugative plasmid. The 3.2 megadalton resistance plasmid, usually associated with PPNG strains originating in Africa, was present in only one third of the PPNG strains. The 2.6 megadalton cryptic plasmid was present in all strains. Prototrophic and proline requiring auxotypes predominated in both PPNG and non-PPNG strains. Arginine requiring auxotypes were found in four of the 16 isolates from asymptomatic women, whereas three of the 22 strains from women with puerperal sepsis and four of the 61 strains from men with urethritis required both proline and arginine. Fifty eight out of 66 PPNG strains with the 4.4 megadalton plasmid required proline compared with 22/38 PPNG strains with the 3.2 megadalton plasmid and 20 of the 51 non-PPNG strains. Three quarters (38/51) of non-PPNG strains belonged to serogroup WII/III as did 42/66 PPNG strains with the 4.4 megadalton plasmid but only 10/38 PPNG strains with the 3.2 megadalton plasmid. In all, 23 different strain types could be recognized on the basis of plasmid content, auxotype, and serogroup. There was, however, a high degree of homogeneity between PPNG and non-PPNG isolates.

Antibiotic resistance, plasmid content and auxotypes of Neisseria gonorrhoeae in Greece.

The antibiotic resistance pattern, the plasmid content and the auxotypes of 27 PPNG and 200 non-PPNG isolates obtained in 1984-1985 were examined. The well-known plasmid patterns, the most frequent was the combination of 4.5 and well-known plasmid patterns, the most frequent was the combination of 4.5 and 2.6 Mdal plasmids. The strains with the Asian-type (4.5 Mdal) plasmid belonged to the auxotypes Pro and Zero, whereas those with the African type (3.2 Mdal) plasmid were of auxotypes Zero, Arg and Pro, Arg. All PPNG strains exhibited reduced sensitivity at least to one of the other antibiotics tested (cefotaxime, spectinomycin, thiamphenicol, tetracycline). Among non-PPNG strains, 19% harboured the conjugative and the cryptic plasmid, 67.5% only the cryptic, 1% only the conjugative and 12% were plasmid-free. The most frequent auxotypes of non-PPNG strains were Zero (65.5%) and Pro (21%), while the uncommon auxotype Pro, Arg degree, Ura was found only in plasmid-free strains with reduced sensitivity to penicillin. Susceptibility testing revealed a large number of non-PPNG strains with decreased sensitivity to antibiotics, the Pro and Zero isolates being less sensitive than those of other auxotypes.

Three regimens of procaine penicillin G, Augmentin, and probenecid compared for treating acute gonorrhoea in men.

The efficacy of three penicillin regimens in treating uncomplicated gonorrhoea in men was evaluated. The regimens consisted of: Augmentin 3.25 g plus probenecid 1 g orally: aqueous procaine penicillin G 4.5 MIU intramuscularly and probenecid 1 g plus one tablet of Augmentin 375 mg orally; or aqueous procaine penicillin G 4.5 MIU intramuscularly and probenecid 1 g plus two tablets of Augmentin 375 mg orally. Cure rates for infections caused by penicillinase (beta lactamase) producing Neisseria gonorrhoeae (PPNG) were 87% (20/23) for regimen 1, 97% (28/29) for regimen 2, and 95% (19/20) for regimen 3. Thus the addition of one or two tablets of Augmentin 375 mg to aqueous procaine penicillin G and probenecid cured 96% (47/49) of infections caused by PPNG strains. All three regimens were 100% effective in eradicating infections caused by non-PPNG strains. Post gonococcal urethritis occurred in 24% of cases treated with regimen 1, 14% of cases treated with regimen 2, and 15% of cases treated with regimen 3. The geometric minimum inhibitory concentrations (MIC90) of Augmentin for 72 PPNG and 162 non-PPNG isolates of N gonorrhoeae obtained before treatment were 1.98 and 0.55 mg/l, respectively. Regimen 2, besides being effective against infections caused by PPNG or non-PPNG strains, has the advantage of cost effectiveness and low toxicity. This regimen may be useful in treating gonorrhoea in areas of high prevalence of PPNG strains, such as South East Asia and Africa.

Susceptibility to antimicrobials of Neisseria gonorrhoeae isolated in Singapore: implications on the need for more effective treatment regimens and control strategies.

The antimicrobial susceptibility of gonococci isolated in Singapore has been studied over several years. In 1983, the prevalence of penicillinase producing Neisseria gonorrhoeae (PPNG) was 33.5% and 64% of non-PPNG isolates had minimum inhibitory concentrations (MICs) of penicillin of greater than or equal to 0.5 mg/l. After a control programme, the isolation of the gonococcus from prostitutes was reduced and there was improvement in its susceptibility to antimicrobials. The incidence of PPNG strains was stabilised with a change in the treatment regimen. An influx of foreign prostitutes, however, had an unfavourable impact on these variables. Countries in South East Asia have a high prevalence of PPNG and non-PPNG strains that have reduced susceptibility to antimicrobials. In view of increased air travel the problem should be seen from a global perspective. Better treatment regimens and control strategies are urgently needed.

Plasmid patterns and in-vitro susceptibility of penicillinase-producing Neisseria gonorrhoeae with emphasis on thiamphenicol: results of surveillance in The Netherlands.

Susceptibility to thiamphenicol was tested, and plasmids were characterized for 1925 strains of penicillinase-producing Neisseria gonorrhoeae (PPNG) isolated in The Netherlands in 1981 and 1982. Of the 1925 isolates, 771 harbored the so-called "Asia" (4.5-megadalton) resistance plasmid and 1154 had the so called "Africa" (3.2-megadalton) plasmid. Isolates in the first group were usually inhibited by 0.25 microgram of thiamphenicol ml, while the MIC for the latter isolates was 1-2 micrograms/ml. A similar bimodal distribution of MICs has been observed for non-PPNG isolates. In the period covering this study, a substantial shift from predominance of the "Africa" type to that of the "Asia" type of N. gonorrhoeae was observed.

ANTIBIOTIC SUSCEPTIBILITY OF NEISSERIA GONORRHOEAE IN RELATION TO SEROGROUPS

Susceptibility testings, by means of the agar-dilution method, were performed on nine antibiotics of 138 non-PPNG (beta-lactamase-producing = PPNG) strains, 17 of which originated from Thailand, and 88 PPNG isolates. The gonococcal strains were sero-grouped by the co-agglutination method and classified among the sero-groups W I, W II or W III. Statistically significant differences in antibiotic susceptibility between non-PPNG strains of the three sero-groups could be demonstrated with strains belonging to sero-group W I as the most sensitive and W III isolates as the most resistant. Non-PPNG strains from Thailand were significantly more resistant than the other non-PPNG isolates of the same sero-group. There was, however, no significant difference in resistance between non-PPNG strains from Thailand and PPNG isolates of the same sero-group. PPNG strains of sero-group W I were significantly more sensitive than PPNG strains of sero-group W II, whereas there was no significant difference between PPNG isolates of sero-groups W II and W III. Non-PPNG strains, not from Thailand, of sero-groups W I and W II were significantly more susceptible to non beta-lactam antibiotics than PPNG strains of corresponding sero-groups, while no such difference could be demonstrated for non-PPNG and PPNG isolates of sero-group W III.