Ceftriaxone in the treatment of ordinary and penicillinase-producing strains of Neisseria gonorrhoeae

In Vitro Bactericidal Activity of Biogenic Copper Oxide Nanoparticles for Neisseria gonorrhoeae with Enhanced Compatibility for Human Cells

Resistance to antibiotics and antimicrobial compounds is a significant problem for human and animal health globally. The development and introduction of new antimicrobial compounds are urgently needed, and copper oxide nanoparticles (CuO NPs) have found widespread application across various sectors including biomedicine, pharmacy, catalysis, cosmetics, and many others. What makes them particularly attractive is the possibility of their synthesis through biogenic routes. In this study, we synthesized biogenic green tea (GT, Camellia sinensis)-derived CuO NPs (GT CuO NPs) and examined their biophysical properties, in vitro toxicity for mammalian cells in culture, and then tested them against Neisseria gonorrhoeae, an exemplar Gram-negative bacterium from the World Health Organization's Priority Pathogen List. We compared our synthesized GT CuOP NPs with commercial CuO NPs (Com CuO NPs). Com CuO NPs were significantly more cytotoxic to mammalian cells (IC50 of 7.32 μg/mL) than GT CuO NPs (IC50 of 106.1 μg/mL). GT CuO NPs showed no significant increase in bax, bcl2, il6, and il1β mRNA expression from mammalian cells, whereas there were notable rises after treatment with Com CuO NPs. GT-CuO NPs required concentrations of 0.625 and 3.125 μg/mL to kill 50 and 100% of bacteria, respectively, whereas Com-CuO NPs needed concentrations of 15.625 and 30 μg/mL to kill 50 and 100% of bacteria, and the antibiotic ceftriaxone killed 50 and 100% with 3.125 and 30 μg/mL. Gonococci could be killed within 30 min of exposure to GT CuO NPs and the NPs could kill up to 107 within 1 h. In summary, this is the first report to our knowledge that describes the bioactivity of biogenic CuO NPs against N. gonorrhoeae. Our data suggest that biogenic nanoparticle synthesis has significant advantages over traditional chemical routes of synthesis and highlights the potential of GT-CuO NPs in addressing the challenges posed by multidrug-resistant Neisseria gonorrhoeae infections.

Efficacy and Safety of Injectable and Oral Antibiotics in Treating Gonorrhea: A Systematic Review and Network Meta-Analysis

Gonorrhea is the second most frequently reported sexually transmitted infectious disease of bacterial origin in the world. Current empiric therapies rely on broad-spectrum antibiotics. However, treatment options are becoming limited due to the rise of drug-resistant gonorrhea. To control the rise of drug-resistant gonorrhea and to identify alternative treatment options, clinicians will have to increasingly rely on experimental evidence for the treatment of gonorrhea patients. Thus, we performed a systematic review and network meta-analysis of all randomized clinical trials about the efficacy and safety of various antibiotic regimens in adults with gonorrhea. We searched all references in Embase and PubMed from the date of their inception to January 2019, and then an updated search was performed in March 2019. Of the 28,843 identified references, 44 fulfilled our selection criteria. We used a network meta-analysis based on a frequentist approach to evaluate the efficacy and safety of 12 injectable and 11 oral antibiotics. The efficacy of treatments was ranked by p score and inconsistency was assessed by a back-calculation method. Certainty of evidence was evaluated by the GRADE system. For injectable drugs, there was no difference in efficacy between a reference antibiotic and other drugs. However, ceftriaxone had significantly better efficacy than cefuroxime (OR, 12.03; 95% CI 3.73–38.79), cephaloridine (OR, 42.41; 95% CI 8.77–205.07), kanamycin (OR, 5.45; 95% CI 1.25–23.70), penicillin (OR, 13.11; 95% CI 4.48–38.37), and spectinomycin (OR, 4.70; 95% CI 1.62–13.62). Thus, ceftriaxone was the most effective injectable drug (p score of 0.924). As for oral drugs, azithromycin was the most effective compound (p score of 0.8633). There were no significant differences in safety between injectable and oral treatments. In our systematic review of randomized controlled trials, we found azithromycin and ceftriaxone to be the most effective antibiotics for the treatment of gonorrhea. This is in line with current guidelines which recommend a combination therapy of azithromycin and ceftriaxone for the treatment of gonorrhea due to increased antimicrobial resistance. Our analysis identified gentamicin and ofloxacin as alternative therapeutics to treat drug-resistant gonorrhea.

A Brief History of Evolving Diagnostics and Therapy for Gonorrhea: Lessons Learned

Progressively decreasing susceptibility of Neisseria gonorrhoeae to the antibiotics recommended for treatment has raised concerns about the public health threat of antibiotic resistant gonorrhea. This is not a new process, and the organism has reliably developed resistance to all modern antibiotics used for treatment since the dawn of the antibiotic era. The history of changing recommendations for gonorrhea therapy is complex, however, and has been influenced by diagnostic test methods and surveillance. Understanding the impact of these influences may provide insights into current approaches to address this reemerging public health challenge. We reviewed available methods for gonorrhea diagnosis, and public health recommendations for gonorrhea treatment. The literature review was supplemented by qualitative interviews with senior investigators whose research helped shape gonorrhea management strategies over the past 50 years. The process of development of antimicrobial resistance to the antibiotics widely used for treatment seems to be inexorable. Many currently voiced concerns are similar to those raised in the past. The public health threat of increasing antimicrobial resistance by N. gonorrhoeae has been amplified as a result of a smaller pipeline introducing new drugs for gonorrhea treatment. Improved methods for gonorrhea diagnosis have also repeatedly influenced appreciation of the burden of disease caused by N. gonorrhoeae. US Public Health Service leadership has also shaped and improved the management of this important public health problem.

The use of cephalosporins for gonorrhea: the impending problem of resistance

Gonorrhea remains an important clinical and public health problem throughout the world. Gonococcal infections have historically been diagnosed by Gram stain and culture but are increasingly diagnosed through nucleic acid tests, thereby eliminating the opportunity for antimicrobial susceptibility testing. Gonococcal infections are typically treated with single-dose therapy with an agent found to cure > 95% of cases. Unfortunately, the gonococcus has repeatedly developed resistance to antimicrobials including sulfonamides, penicillin, tetracyclines and fluoroquinolones. This has now left third-generation cephalosporins as the lone class of antimicrobials recommended as first-line therapy for gonorrhea in some regions. However, resistance to oral third-generation cephalosporins has emerged and spread in Asia, Australia and elsewhere. The mechanism of this resistance seems to be associated with a mosaic penicillin binding protein (penA) in addition to other chromosomal mutations previously found to confer resistance to beta-lactam antimicrobials (ponA, mtrR, penB, pilQ). Few good options exist or are in development for treating cephalosporin-resistant isolates, as most have had multidrug resistance. Preventing the spread of resistant isolates will depend on ambitious antimicrobial management programs, strengthening and expanding surveillance networks, and through effective sexually transmitted disease control and prevention.

Comparison of ciprofloxacin and ceftriaxone as single-dose therapy for uncomplicated gonorrhea in women

Although women bear the brunt of gonococcal infection-related morbidity, few large studies of gonorrhea treatment in women have been conducted. In a multicenter, double-blind, placebo-controlled trial, 181 evaluable women with uncomplicated gonorrhea were treated with ciprofloxacin (250 mg orally; 94 women) or ceftriaxone (250 mg intramuscularly; 87 women). Twenty-four percent of the participants were infected with antibiotic-resistant Neisseria gonorrhoeae. Cervical gonorrhea was cured in 100% (93 of 93) of the women treated with ciprofloxacin and 99% (83 of 84) receiving ceftriaxone. All pharyngeal (n = 5) or rectal (n = 20) infections treated with ciprofloxacin were cured, as were ceftriaxone-treated patients with pharyngeal (n = 6) or rectal (n = 21) infection. Geometric mean MICs (range) for 248 pretreatment isolates were: penicillin, 0.28 (0.015 to 8.0); tetracycline, 0.46 (0.06 to 4); ciprofloxacin, 0.003 (0.002 to 0.015); and ceftriaxone, 0.004 (0.001 to 0.125) microgram/ml. Both drugs were well tolerated. Despite the high prevalence of antibiotic-resistant gonococci in these populations, 250 mg of oral ciprofloxacin was as effective as an injection of ceftriaxone.

Cephalosporin-probenecid drug interactions

The effect of concurrent probenecid administration on the pharmacokinetics of cephalosporin antibiotics varies with the available cephalosporins. Most cephalosporins are affected to some degree by concurrent probenecid administration, although ceforanide, ceftazidime, ceftriaxone and latamoxef (moxalactam) have no significant changes in pharmacokinetics. For those cephalosporins affected by probenecid, the predominant findings are impairment in renal clearance resulting in increased peak serum concentrations, an increased area under the concentration-time curve (AUC), and both delayed and prolonged recovery of the cephalosporin in the urine. The distribution of the cephalosporins is affected to varying degrees, with reports of increased penetration into ocular, central nervous system and blister fluids noted with some agents. The clinical relevance of the changes in cephalosporin distribution associated with probenecid administration has not been investigated. The dose and timing of probenecid administration appear to be major determinants in any possible interaction. Studies with ceftizoxime and cefoxitin suggest that larger probenecid doses result in greater changes in the pharmacokinetics of cephalosporins. Prolonged probenecid therapy before administration of a cephalosporin did not seem to be as relevant as the probenecid dosage in determining the magnitude of the interaction. Probenecid administration with or immediately before cephalosporin administration appears able to produce these documented changes in cephalosporin pharmacokinetics. The route of administration (oral versus parenteral) of either prolosporin pharmacokinetics. The route of administration (oral versus parenteral) of either probenecid or the cephalosporin does not appear to influence the characteristics of the interactions. The therapeutic efficacy of a combination of a cephalosporin with probenecid has been most thoroughly studied for single-dose treatment of gonorrhoea. The addition of probenecid to cephalosporin therapy results in sustained systemic concentrations adequate for eradication of Neisseria gonorrhoeae. Regimens involving either second or third generation cephalosporins demonstrate good success rates with single-dose therapy. However, the success of ceftriaxone administered alone for treatment of both penicillase-producing and non-penicillase-producing strains of N. gonorrhoeae suggests that the addition of probenecid is unnecessary. The use of probenecid, in combination with cephalosporins, to enhance the treatment of other venereal and systemic infections has preliminary, inconclusive support.

Susceptibility to cephalosporins of penicillin-susceptible and penicillin-resistant strains of Neisseria gonorrhoeae from Philadelphia

Using agar dilution, we determined MICs of penicillin, cefoxitin, ceftriaxone, cefmetazole, tetracycline, and spectinomycin for 129 strains of Neisseria gonorrhoeae. All strains were susceptible to ceftriaxone (MIC range, less than or equal to 0.008 to 0.06 micrograms/ml) and spectinomycin (16 to 32 micrograms/ml). The MICs for 50, 90, and 100% of strains tested were 1.0, 2.0, and greater than 8.0 micrograms/ml; 0.12, 1.0, and greater than 8.0 micrograms/ml; 0.5, 1.0, and 2.0 micrograms/ml; and 1.0, 2.0, and greater than 8.0 micrograms/ml for cefmetazole, penicillin, cefoxitin, and tetracycline, respectively. Seven strains were beta-lactamase producers; eight were chromosomally resistant to penicillin. There was a log-linear relation for non-beta-lactamase-producing strains between the MICs of cefmetazole, cefoxitin, and tetracycline and the MIC of penicillin (Pearson r = 0.787, 0.544, and 0.358, respectively).

Ceftriaxone. A reappraisal of its antibacterial activity and pharmacokinetic properties, and an update on its therapeutic use with particular reference to once-daily administration

Since ceftriaxone was first reviewed in the Journal, further studies have confirmed its broad antibacterial spectrum in vitro and extended its clinical documentation in comparative studies with other widely used drugs in infections of the urinary and lower respiratory tract, meningitis in infants and children, uncomplicated gonorrhoea, perioperative prophylaxis in patients undergoing surgery, and in several other types of infection. As in earlier studies, which primarily used a twice-daily dosage regimen, few significant differences were found between therapeutic groups in comparative studies and results have demonstrated the efficacy of once-daily ceftriaxone in all but the most serious infections, such as sole antibiotic therapy in pseudomonal infections. Wider clinical experience has established that ceftriaxone is generally well tolerated. Thus, ceftriaxone now has a well-defined place as an appropriate alternative for the parenteral treatment of a variety of infections due to susceptible organisms, as well as for perioperative prophylaxis of surgery, and may offer advantages of greater convenience over other parenteral antibiotics which are administered more frequently.

Cefodizime in serum and skin blister fluid after single intravenous and intramuscular doses in healthy volunteers

In gonorrhea therapy, cephalosporins are conventionally administered by intramuscular (i.m.) injection, which rather frequently leads to local side effects. To investigate whether the well-tolerated intravenous (i.v.) injection of cephalosporins may be of comparable gonocidal effect, levels of cefodizime, a new broad-spectrum cephalosporin, in serum and tissue fluid (suction blister and cantharides blister fluid) were determined in six healthy men. Single doses of 1 g of cefodizime were injected i.v. and i.m. according to a randomized crossover design. On i.m. injection the drug was completely bioavailable, and the peak concentration in serum was 75 +/- 8 micrograms/ml. The terminal half-life of serum levels was 2.4 h. Cefodizime concentrations in the blister fluids increased for 1.5 to 3 h after the i.v. dose and for at least 3 h on i.m. administration. The concentrations of non-protein-bound cefodizime in blister fluid already exceeded the MIC for 90% of Neisseria gonorrhoeae strains 10 min after i.v. injection and 20 to 30 min after the i.m. dose. At 6 h after each dose, active concentrations were still present in serum. The results suggest that cefodizime administered i.v. and i.m. has equivalent high cure rates in uncomplicated gonorrhea. This hypothesis should be tested further by a controlled clinical trial. If equivalent, i.v. administration excels because it is better tolerated locally.

Role of cephalosporins in gonorrhoea and other sexually transmitted diseases

Cephalosporins have a role in the treatment of gonorrhoea, and especially infections caused by strains that are penicillin-resistant, either because they produce plasmid-mediated beta-lactamase or they have chromosomally mediated diminished permeability or modified penicillin-binding proteins. Although none of the oral or Group I agents are useful, most of the Group II, III and IV agents are, and especially cefuroxime, cefotaxime, ceftriaxone and cefoxitin. In addition to uncomplicated urethral, cervical or rectal infections, appropriate regimens are also effective for the treatment of pharyngeal infections, disseminated infections and gonococcal ophthalmia. The cephalosporins have no clear role in the treatment of syphilis, granuloma inguinale, Mycoplasma or chlamydial infections or bacterial vaginosis, but ceftriaxone may be effective in chancroid, and cefoxitin in combination with an antichlamydial agent (such as a tetracycline) might be used for the treatment of pelvic inflammatory disease.

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.

Randomised comparative study of ceftriaxone and spectinomycin in gonorrhoea

From 26 April to 30 June 1983 a total of 200 men with uncomplicated gonococcal urethritis were randomly treated with either 2 g spectinomycin or 250 mg ceftriaxone, both administered intramuscularly. Of 197 isolates tested for the presence of the enzyme beta lactamase, 91 (46.2%) were positive (PPNG) and 106 (53.8%) were non-PPNG strains. All 93 patients treated with spectinomycin and followed up and 97 treated with ceftriaxone and followed up were cured. Ceftriaxone 250 mg administered by intramuscular injection is highly effective in treating gonococcal infections caused by both PPNG and non-PPNG strains and is an appropriate alternative to spectinomycin.

Rosoxacin in the treatment of uncomplicated gonorrhoea in men

Between 3 January and 4 March 1983 we treated 200 male patients diagnosed as having uncomplicated gonococcal urethritis with one of two regimens. They were divided into two groups and randomly assigned to treatment with either 2 g spectinomycin administered intramuscularly (group A) or 300 mg rosoxacin by mouth (group B). Of 187 isolates tested for the production of beta-lactamase, 101 (54%) were penicillinase producing Neisseria gonorrhoeae (PPNG) strains. All 81 cases followed in group A (spectinomycin) were cured, compared with 88.5% (77 out of 87) of the patients followed in group B (rosoxacin). We concluded that rosoxacin at a dosage of 300 mg administered orally was fairly effective in the treatment of gonococcal urethritis in men caused by both PPNG and non-PPNG strains.

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

Ceftriaxone is a new 'third generation' semisynthetic cephalosporin with a long half-life which has resulted in a recommended once daily administration schedule. It is administered intravenously or intramuscularly and has a broad spectrum of activity against Gram-positive and Gram-negative aerobic, and some anaerobic, bacteria. The activity of ceftriaxone is generally greater than that of the 'first' and 'second generation' cephalosporins against Gram-negative bacteria, but less than that of the earlier generations of cephalosporins against many Gram-positive bacteria. Although ceftriaxone has some activity against Pseudomonas aeruginosa, on the basis of present evidence it cannot be recommended as sole antibiotic therapy in pseudomonal infections. Ceftriaxone has been effective in treating infections due to other 'difficult' organisms such as multidrug-resistant Enterobacteriaceae. Ceftriaxone was effective in complicated and uncomplicated urinary tract infections, lower respiratory tract infections, skin, soft tissue, bone and joint infections, bacteraemia/septicaemia, and paediatric meningitis due to susceptible organisms. In most of these types of infections once-daily administration appears efficacious. Results were also encouraging in a few patients with ear, nose and throat, intra-abdominal, obstetric and gynaecological infections, and adult meningitis, but conclusions are not yet possible as to the efficacy of the drug in these indications due to limited experience. A single intramuscular dose of ceftriaxone has been compared with standard therapy for gonorrhoea due to non-penicillinase-producing and penicillinase-producing strains of Neisseria gonorrhoeae and shown to be highly effective. In a few small trials the comparative efficacy of ceftriaxone and other antibacterials has been assessed in other types of infections and in perioperative prophylaxis in patients undergoing surgery. Few significant differences in response rates were found between therapeutic groups in these comparative studies, but larger well-designed studies are needed to more clearly assess the comparative efficacy of ceftriaxone and other antimicrobials, especially the aminoglycosides and other 'third generation' cephalosporins, and to confirm the apparent lack of serious side effects with ceftriaxone. If more widespread use confirms the safety and efficacy of ceftriaxone, it will offer an important alternative, particularly for the treatment of serious infections due to multidrug-resistant Gram-negative bacteria and in situations where the long half-life of the drug could result in worthwhile convenience and cost benefits.

Antimicrobial sensitivity of Neisseria gonorrhoeae. Comparison of penicillinase producing and non-penicillinase producing strains

The sensitivity of 42 strains of penicillinase producing Neisseria gonorrhoeae (PPNG) and 46 strains of non-PPNG was tested against benzyl penicillin, spectinomycin, erythromycin, cefuroxime, ceftriaxone, tetracycline, sulphamethoxazole, and trimethoprim. The minimum inhibitory concentrations (MICs) of all antimicrobials, except trimethoprim and ceftriaxone, differed significantly for PPNG and non-PPNG strains. Ceftriaxone was the most active compound tested, the MIC for all strains being less than or equal to 0.015 mg/1. PPNG were less sensitive than non-PPNG strains to spectinomycin. It remains to be seen whether the increase in prevalence of PPNG strains is followed by a gradual increase in low level resistance to spectinomycin as well as the occasional finding of high level resistance to this antibiotic.