Neisseria gonorrhoeae strains isolated in Hong Kong: in vitro susceptibility to 13 antibiotics

Effect of penicillin and spectinomycin given for urethritis and cervicitis with Neisseria gonorrhoeae: high prevalence of penicillin-resistant isolates

Efficacy of single-dose spectinomycin (TRO: 2 g intramuscularly) was compared with that of aqueous procaine penicillin G (APPG:4.8 x 10(6) units) plus 1 g of probenecid for treatment of gonococcal urethritis and cervicitis. Cure rates of the 210 patients who received TRO and 190 patients who received APPG were 97.6% and 91.1%, respectively. MICs of antibiotics were determined using the agar dilution method. Those isolates with MICs of APPG of less than 1.0 microgram/ml had low failure rates (2.9%), while strains with increased resistance to APPG (MICs greater than or equal to 1.0 microgram/ml) had higher failure rates (24%). Treatment failures seen with TRO were not correlated to isolates with the higher MICs. Clinical results suggest TRO could be given for treatment of genital gonorrhoea in Puerto Rico due to the high prevalence of both chromosomally-mediated penicillin-resistant Neisseria gonorrhoeae (20%) and penicillinase-producing Neisseria gonorrhoeae (7.5%) strains and the high rate of failure seen with the use of APPG.

Gonococcal keratoconjunctivitis

Gonococcal keratoconjunctivitis is a potentially devastating infection, because Neisseria gonorrhoeae can cause a rapid, severe, ulcerative keratitis resulting in visual loss. The therapeutic decision making process is complicated by the necessity for prompt, effective parenteral therapy, frequent coinfection with other sexually transmitted diseases, and emergence of antibiotic resistance. Because of the evolving problem of antibiotic resistance and the need for cost containment, the current recommendations of hospitalization for intravenous penicillin may need to be modified. The third generation cephalosporin, ceftriaxone, has properties that suggest it may be the best available antimicrobial agent as a single-dose treatment of gonococcal conjunctivitis. Spectinomycin may be a useful alternative in the penicillin-allergic adult patient.

In-vitro susceptibility of 400 isolates of Neisseria gonorrhoeae in Vancouver, 1982-84

Consecutive isolates of Neisseria gonorrhoeae obtained at a sexually transmitted disease clinic in Vancouver between June 1982 and June 1984 were tested for in-vitro susceptibility to eight antimicrobial agents. Of the 400 isolates 6 (1.5%) were penicillinase-producing N. gonorrhoeae, and for 25 (6.2%) the minimum inhibitory concentrations (MICs) of penicillin were 1.0 to 4.0 micrograms/ml. Ceftriaxone sodium was the most active agent. The MICs were higher than those reported in a Canadian study in 1973-74, except for tetracycline hydrochloride. The patterns of susceptibility of the isolates to one antimicrobial agent correlated significantly with those to each other agent, although the relation was weakest for trimethoprim-sulfamethoxazole and spectinomycin. The results reinforce the need to evaluate local in-vitro susceptibility patterns, especially since the proportion of isolates with relative and absolute resistance to penicillin is increasing.

In vitro activity of Ro 15-8074, a new oral cephalosporin, against Neisseria gonorrhoeae

Ro 15-8074, a new cephalosporin the pivaloyloxymethylester of which (Ro 15-8075) is orally absorbable, showed greater in vitro activity than cefaclor against 48 Neisseria gonorrhoeae strains, including 25 penicillinase-producing strains. Unlike cefaclor, Ro 15-8074 was unaffected by increase in inoculum size, and it exhibited a remarkable stability against gonococcal beta-lactamase hydrolysis.

In vitro susceptibility of Neisseria gonorrhoeae to 2-acetylpyridine thiosemicarbazones

MICs of 20 2-acetylpyridine thiosemicarbazones and penicillin were determined for 25 clinical isolates of beta-lactamase-positive and beta-lactamase-negative Neisseria gonorrhoeae strains. The compounds most active against the beta-lactamase-producing strains were the N4,N4-disubstituted derivatives and the thiosemicarbazone derivatives of the 2-acetylpyridines, followed by the other compounds related to the 2-acetylpyridine thiosemicarbazones.

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.

In vitro antimicrobial susceptibilities of penicillinase-producing and non-penicillinase-producing strains of Neisseria gonorrhoeae isolated in Durban, South Africa

The in vitro susceptibilities of 22 penicillinase-producing and 32 non-penicillinase-producing strains of Neisseria gonorrhoeae to 13 antimicrobial agents, including the new semisynthetic penicillins and cephalosporins, are reported. Ceftriaxone, ceftazidime, and cefotaxime were the most active agents tested; none of them had an MIC of greater than 0.03 micrograms/ml. Amoxycillin plus clavulanic acid and temocillin also showed good activity against both strains of gonococci.

Antimicrobial susceptibility of Neisseria gonorrhoeae isolated in Durban, South Africa

One hundred and forty clinical isolates of Neisseria gonorrhoeae were screened for production of penicillinase by the intralactam strip method and chromogenic cephalosporin test. Minimum inhibitory concentrations (MICs) of penicillin, ampicillin, tetracycline, cefoxitin, cefuroxime, cefotaxime, sulphamethoxazole-trimethoprim (ratio 19/1), and spectinomycin, were measured for 100 strains by the agar dilution method. Seven (5%) of the 140 isolates were identified as penicillinase producing N gonorrhoeae (PPNG). The MICs of penicillin for the seven PPNG strains ranged from 0 X 25 mg/1 to 2 mg/1. Of the 93 non-PPNG strains, 80 (86%) were fully susceptible to penicillin with MICs ranging from 0 X 0037 mg/1 to 0 X 06 mg/1 and 13 (14%) were of intermediate penicillin resistance with MICs greater than or equal to 0 X 125 mg/1. Of the 100 isolates tested, 86% were fully susceptible to tetracycline with MICs of less than 1 mg/1. No spectinomycin resistant strains were encountered in this study. All gonococcal strains were susceptible to the cephalosporins tested as well as to sulphamethoxazole-trimethoprim.

Characterization of Neisseria cinerea, a nonpathogenic species isolated on Martin-Lewis medium selective for pathogenic Neisseria spp

An asaccharolytic, gram-negative, oxidase-positive diplococcus was isolated on Martin-Lewis medium from the cervix of a patient attending an arthritis clinic at Seattle Public Health Hospital, Seattle, Wash. This strain, NRL 32165, did not produce detectable acid from glucose, maltose, sucrose, fructose, mannitol, or lactose in either cystine Trypticase agar (BBL Microbiology Systems, Cockeysville, Md.) or modified oxidation-fermentation medium and was identified presumptively as a glucose-negative Neisseria gonorrhoeae strain, but was identified later as Neisseria cinerea on the basis of its biochemical reactions. Nitrate was not reduced, nitrite (0.001%, wt/vol) was reduced, and polysaccharide was not produced from sucrose. Proline, arginine, and cystine-cysteine were required for growth on defined medium. Strain NRL 32165 did not react with antigonococcal protein I monoclonal antibodies and did not produce immunoglobulin A protease. In DNA:DNA homology studies with N. gonorrhoeae NRL 8038 (F62) and N. cinerea type strain NRL 30003, strain NRL 32165 showed 95% homology relative to N. cinerea and 44% homology relative to N. gonorrhoeae. Thus, the identity of strain NRL 32165 was confirmed as N. cinerea (von Lingelsheim 1906) Murray 1939. Of all Neisseria spp., N. cinerea is most likely to be misidentified as a glucose-negative N. gonorrhoeae strain.

In vitro antimicrobial susceptibility of penicillinase-producing and intrinsically resistant Neisseria gonorrhoeae strains

The in vitro susceptibility of penicillinase-producing and intrinsically resistant Neisseria gonorrhoeae strains to 13 antimicrobial agents was tested. Regardless of the type of resistance, these organisms remained quite susceptible to newer cephalosporin agents, including moxalactam, cefoperazone, cefotaxime, and ceftazidime.

Cefotaxime. A review of its antibacterial activity, pharmacological properties and therapeutic use

SYNOPSIS

Cefotaxime is a new 'third generation' semisynthetic cephalosporin administered intravenously or intramuscularly. It has a broad spectrum of activity against Gram-positive and Gram-negative aerobic and anaerobic bacteria, and is generally more active against Gram-negative bacteria than the 'first' and 'second generation' cephalosporins. Although cefotaxime has some activity against Pseudomonas aeruginosa, on the basis of present evidence it cannot be recommended as sole antibiotic therapy for pseudomonal infections. However, cefotaxime has been effective in treating infections due to other 'difficult' organisms, such as multidrug-resistant Enterobacteriaceae. Like other cephalosporins, cefotaxime is effective in treating patients with complicated urinary tract and lower respiratory tract infections, particularly pneumonia caused by Gram-negative bacilli. High response rates have also been achieved in patients with Gram-negative bacteraemia. Although favourable clinical results have been obtained in patients with infections caused by mixed aerobic/anaerobic organisms (such as peritonitis or soft tissue infections), the relatively low in vitro activity of cefotaxime against Bacteroides fragilis may restrict its usage in situations where this organism is the suspected or proven pathogen. In preliminary studies, males and females treated with a single intramuscular dose of cefotaxime for uncomplicated gonorrhoea caused by penicillinase-producing strains of Neisseria gonorrhoeae responded very favourably. Encouraging results have also been reported in open studies in children including neonates, treated with cefotaxime for meningitis and various other serious infections. In some situations, cefotaxime has been given in combination with another antibiotic such as an aminoglycoside, but the merits of such a combination have not been clearly established. Whether cefotaxime alone is appropriate therapy for conditions previously treated with aminoglycosides (other than pseudomonal infections) also needs additional clarification, but if established as equally effective in such conditions cefotaxime offers potentially important clinical and practical advantages in its apparent lack of serious adverse effects and freedom from the need to undertake drug plasma concentration monitoring.

In vitro susceptibility of 50 non-beta-lactamase-producing Neisseria gonorrhoeae strains to 12 antimicrobial agents

The in vitro activities of six commonly used antibiotics and six newer beta-lactam agents were determined in 50 consecutive clinical isolates of beta-lactamase-negative Neisseria gonorrhoeae. The gonococci isolated were notably resistant to penicillin, ampicillin, erythromycin, and tetracycline, whereas all of the strains were susceptible to the newer beta-lactam agents cefoxitin and spectinomycin.

Antibiotic susceptibility of pneumococci and Haemophilus influenzae isolated from patients with acute exacerbations of chronic bronchitis: prevalence of tetracycline-resistant strains in Hong Kong

The susceptibility of 119 respiratory isolates of Haemophilus influenzae and 87 respiratory isolates of Streptococcus pneumoniae to various antibiotics was tested by means of an agar dilution method and an inoculum size of 10(3) colony forming units (c.f.u.). The antibiotics tested included penicillin/ampicillin, erythromycin, tetracycline, chloramphenicol and four third-generation cephalosporins, cefotaxime, cefoperazone, ceftriaxone and moxalactam. Fifty-eight per cent of the pneumococcal strains and 23 per cent of the H. influenzae strains tested were found resistant to tetracycline (MICs = 4-128 mg/l and 4-64 mg/l, respectively). None of the isolates tested was resistant to erythromycin or chloramphenicol. Three per cent of Haemophilus strains tested were beta-lactamase producing and thus resistant to ampicillin (MICs = 2-8 mg/l), while none of the pneumococcal strains tested was penicillin-resistant. Three of the newer third-generation cephalosporins--cefotaxime, cefoperazone and ceftriaxone--were highly active against both H. influenzae and Str. pneumoniae while moxalactam, though also active, was comparatively less effective.

In vitro susceptibility and cross-resistance of South African isolates of Neisseria gonorrhoeae to 14 antimicrobial agents

One hundred isolates of Neisseria gonorrhoeae obtained from patients attending clinics in Johannesburg, South Africa, were tested by a broth dilution technique for their minimal inhibitory concentrations (MICs) of benzyl penicillin G, ampicillin, cefoxitin, cefuroxime, cefotaxime, ceftriaxone, ceftazidime, tetracycline, minocycline, doxycycline, spectinomycin, rosaramicin, chloramphenicol, and rosoxacin. None of the isolates tested produced beta-lactamase. The MICs of penicillin ranged from less than or equal to 0.007 to 0.5 micrograms/ml. The isolates were also very susceptible to rosaramicin (minimal concentration at which 50% of isolates were inhibited [MIC50] = 0.02 micrograms/ml) and to the new cephalosporins (cefotaxime MIC50 less than 0.007 micrograms/ml, ceftriaxone MIC50 less than 0.007 micrograms/ml, and ceftazidime MIC50 less than 0.007 micrograms/ml). By using regression analysis, good correlation was observed between the MICs of penicillin and those of the other agents, with the exception of ceftriaxone, spectinomycin, and rosaramicin. The MICs and the minimal bactericidal concentrations were within a log2 concentration of each other.

Gonococcal opacity variants: susceptibility to antimicrobial agents

We tested the susceptibility of 34 pairs of isogenic opaque and transparent colony variants of gonococci to nine antimicrobial agents. Only 20% of the opaque and transparent minimal inhibitory concentrations were discordant, and the mean minimal inhibitory concentrations were not significantly different. Selection of opacity variants is, therefore, not necessary for routine susceptibility testing.

Comparative in-vitro activity of selected new beta-lactam antimicrobials against Neisseria gonorrhoeae

Four new beta-lactam antimicrobials, ceftriaxone, cefotiam, cefonicid, and mecillinam, were evaluated in vitro against 72 beta-lactamase-negative and 26 beta-lactamase-positive isolates of Neisseria gonorrhoeae. Ceftriaxone was the most active of the antimicrobials tested. It inhibited all isolates, regardless of beta-lactamase activity, at a concentration of less than or equal to 0.015 microgram/ml. Cefotiam and cefonicid were also active against both groups but not as active as ceftriaxone. Both groups of N gonorrhoeae showed a high degree of resistance against mecillinam.

Comparative in vitro activity of cefmenoxime, cefotaxime, cefuroxime, cefoxitin, and penicillin against Neisseria gonorrhoeae

The in vitro activity of a new beta-lactam antibiotic, cefmenoxime, was compared with those of cefotaxime, cofuroxime, cefoxitin, and penicillin against 72 beta-lactamase-negative and 26 beta-lactamase-positive Neisseria gonorrhoeae. Cefmenoxime was as active as cefotaxime and more active than the other three antimicrobial agents. It inhibited all isolates, regardless of beta-lactamase activity, at a concentration of less than or equal to 0.015 microgram/ml.

Ceforanide and cefazolin therapy of pneumonia: comparative clinical trial

Ceforanide is a new (parenteral) long-acting cephalosporin with antimicrobial activity comparable to those of other second-generation cephalosporins. In a randomized prospective study, patients with community-acquired bacterial pneumonia were treated with ceforanide at 0.5 g every 12 h (28 cases) or with cefazolin at 1.0 g every 8 h (26 cases). The study groups were comparable in clinical and laboratory findings, including etiological diagnosis. Streptococcus pneumoniae was isolated from the sputum of 38 patients, of whom 8 (21%) were bacteremic. Mean peak and trough serum levels of ceforanide drawn 1 and 11.5 h after the 0.5-g intravenous dose were 39.6 and 2.5 microgram/ml, respectively. Of the 50 patients evaluable for efficacy, all responded clinically with no serious adverse reactions. In spite of clinical improvement and in vitro susceptibility, Haemophilus influenzae persisted in the sputum of five of the eight cefazolin-treated patients and four of the five patients treated with ceforanide. Ceforanide appears to be as safe and effective as cefazolin for the therapy of pneumonia caused by S. pneumoniae or H. influenzae, but neither drug was effective in clearing H. influenzae from the sputum.

In vitro susceptibility of Haemophilus influenzae and neisseria gonorrhoeae to Ro 13-9904 in comparison with other beta-lactam antibiotics

Ro 13-9904 has high in vitro activity, as does cefotaxime, against 57 Haemophilus influenzae and 60 Neisseria gonorrhoeae strains, including 5 and 11 beta-lactamase-producing strains in each group, respectively.