上海市淋球菌耐药流行株的聚类分析

目的 对目前淋球菌流行株的抗生素耐药性及各种抗生素敏感情况分类。方法 收集临床就诊淋病病人资料并分离出病原体102株，采用琼脂稀释法测定球菌对抗生素的敏感性，并对102株淋球球菌株和所测定的抗生素进行系统聚类。结果 102株淋球菌流行株按其耐药性可以分为6类，所测定的抗生素敏感情况可以分为3类。结论 运用聚类分析方法，可以根据耐药敏感表型进一步了解淋球菌流行株之间的相关性。     

淋病奈瑟菌常见抗生素耐药机制的研究进展

淋病奈瑟菌是淋病的病原菌。淋病目前在我国性传播疾病中感染率较高,有效的抗生素治疗是防治淋病的主要方法,但淋病奈瑟菌可通过改变作用靶点、改变对细胞膜的通透性、产生抗生素灭活酶以及药物外排机制等方式降低对抗生素的易感性。为了更好地指导临床用药、对淋病进行预防和防治,需要严密监测淋病奈瑟菌的耐药情况。本文针对淋病奈瑟菌常见抗生素的耐药机制进行综述。     

广州地区淋球菌对环丙沙星耐药的监测与分析

目的 为了解广州地区1998～2002年淋球菌对环丙沙星敏感性和耐药性的变迁。方法 采用琼脂稀释法测定环丙沙星对每年分离的淋球菌的最低抑菌浓度(MIC)。结果 对1998～2002年在广州市性病监测中心就诊的性病患者中分离到的603株淋球菌，进行耐药性分析，环丙沙星的敏感率由1998年的12％降至2002年的零敏感，而耐药率由1998年的56．5％上升至2002年的98％。结论 广州地区流行的淋球菌的耐药情况日趋严重，喹诺酮类药物的高耐药率表明已不再适宜被推荐为治疗淋病的一线药物。有必要持续监测淋球菌的耐药性，并减少抗菌药物的滥用，以保证药物的敏感性。     

Emergence of quinolone-resistant Neisseria gonorrhoeae in Pakistan

Quinolone-resistant Neisseria gonorrhoeae (QRNG) have not been reported from Pakistan to date. This is the first report of the presence of QRNG in Pakistan. The study was performed at a tertiary care hospital laboratory in Karachi, Pakistan. Antimicrobial susceptibility data on all N. gonorrhoeae isolated between 1992 and 2002 were retrieved and analysed. Minimum inhibitory concentrations (MICs) of QRNG isolated in year 2002 were performed, and clinical information was collected. QRNG was first noted in 1999 and its proportion increased to 42% in 2002. MICs of the 12 isolates tested in 2002 showed a high level of resistance to ofloxacin with MIC of more than 4 microg/mL. Clinical information from patients with QRNG showed treatment failure. Emergence of QRNG in developing countries is alarming as there is no proper surveillance of increase in resistance. We strongly urge the need of detection and documentation of the resistant gonococcal isolates, as in vitro resistance is associated with clinical failure.     

广州地区奈瑟氏淋球菌对头孢妥仑耐药性的监测与分析

目的 了解广州地区奈瑟氏淋球菌对头孢妥仑的药物敏感性和耐药性。方法 采用琼脂稀释法测定头孢妥仑对分离的耐瑟氏淋球菌的最低抑菌浓度（MIC）。结果 头孢妥仑的MIC90由1993年的0．125mg／L上升至2004年的0．5mg／L，其敏感度下降2个对倍稀释度，而同一时间其它抗菌药MIC值的变化则远远大于该监测数据。该研究中未发现对头孢妥仑的耐药菌株。结论 目前广州地区流行的奈瑟氏淋球菌的耐约情况日趋严重，喹喏酮类药物的高度耐药率表明已不再适宜被推荐为治疗淋病的一线药物。头孢妥仑对奈瑟氏淋球菌仍然处于良好的敏感状态，推荐用于淋病的治疗有良好的临床疗效。但考虑到淋球菌对各种抗生素敏感度的变化，有必要监测奈瑟氏淋球菌的耐药性，减少抗菌药物的滥用，保证药物的敏感性。     

Antimicrobial resistance pattern of Neisseria gonorrhoeae isolates from peripheral health centres and STD clinic attendees of a tertiary care centre in India

The aim of the study was to compare the antimicrobial resistance pattern of Neisseria gonorrhoeae isolates from urban and rural peripheral health centres and from sexually transmitted disease (STD) clinic attendees. Antimicrobial susceptibility testing of 191 N. gonorrhoeae isolates (165 isolates from STD clinic attendees and 26 from peripheral health centres) was carried out in Delhi, India, using the calibrated dichotomous sensitivity technique for penicillin, tetracycline, ceftriaxone, ciprofloxacin, spectinomycin and nalidixic acid, and minimum inhibitory concentrations were determined using E-test. Penicillin-resistant, ciprofloxacin-resistant, penicillinase-producing N. gonorrhoeae and tetracycline-resistant N. gonorrhoeae strains were higher in STD clinic attendees than in peripheral health centres, probably because of less antibiotic pressure in the peripheral areas. High-level resistance to ciprofloxacin and multiresistant strains were also higher in STD clinic attendees. The present study emphasizes the importance of surveillance of antimicrobial resistance of N. gonorrhoeae in different population subgroups in order to monitor the spread of multiresistant strains and to update the national treatment recommendations.     

Molecular typing of Neisseria gonorrhoeae from hospital and community isolates by restriction fragment length polymorphism

Strains of Neisseria gonorrhoeae are generally characterized by auxotyping, serotyping, plasmid profile, antibiotic sensitivity and deoxyribonucleic acid (DNA) amplification fingerprinting. The aim of this study was to analyse the generation of restriction fragment length polymorphism (RFLP) patterns by BgIII digestion of total genomic DNA of N. gonorrhoeae isolated from the community (n =30) and the hospital (n =15) and to establish an association with serogrouping and antibiogram. The RFLP patterns produced by BgIII restriction digestion showed 7 different patterns among 30 community isolates and 9 different patterns among 15 hospital isolates. 66.7% of isolates belonged to serogroup WI. Penicillin resistance was observed in 46.7% of community isolates and 66.7% hospital isolates. However, penicillinase producing N. gonorrhoeae (PPNG) were lower in the community (6.6%) than in the hospital isolates (53.3%). PPNG strains were more often seen in serogroup WI. This is the first Indian report on RFLP genotype pattern in N. gonorrhoeae. We noted differences in RFLP genotypes of the community (RFLP types 1, 2, 3, 4, 5 and 7) and hospital strains (RFLP types 6 and 8), while no differences in the serogroup were observed. Ciprofloxacin resistance was 20.0% and 26.6% in the community and hospital isolates, respectively. Ceftriaxone emerges as the current drug of choice for an effective policy of antibiotic treatment of gonorrhoea through syndromic management in developing countries.     

Gonococcal resistance: evolving from penicillin, tetracycline to the quinolones in South Africa -- implications for treatment guidelines

Resistant Neisseria gonorrhoeae has been evolving. This study assessed the antimicrobial susceptibility profile of isolates in the Pretoria region, South Africa. Isolates of N. gonorrhoeae from men with urethritis were tested for susceptibility to eight antimicrobial agents by disc diffusion, Etest and agar dilution methods. Chromosomal resistance to penicillin was found in 16% of isolates, 16% showed plasmid-mediated resistance and decreased susceptibility was seen in 73% of isolates. For the first time, there is evidence of high-level tetracycline resistance (36%). Ciprofloxacin resistance emerged at 7%. All isolates remained susceptible to ceftriaxone. In view of these findings of the emergence of quinolone-resistant N. gonorrhoeae, national treatment guidelines for syndromic management of sexually transmitted infections need to be urgently reviewed. The injectable preparation, ceftriaxone has to be considered as a first-line agent for the management of gonococcal infections. Overall, the gonococcal isolates in the Pretoria region remain susceptible to ceftriaxone, cefoxitin, cefpodoxime and spectinomycin.     

济宁地区淋球菌临床分离株对抗生素的耐药性检测

琼脂平皿稀释法测定临床收集的100株淋球菌对青霉素的耐药率为97.0%,对氧氟沙星、多西环素和阿奇霉素的耐药率分别为89.0%、87.0%和63.0%,对头孢曲松和壮观霉素的耐药率为9.0%和6.0%。表明济宁地区淋球菌对常用抗生素的耐药性较严重。     

DNA gyrase gene in Neisseria gonorrhoeae as indicator for resistance to ciprofloxacin and species verification

We have identified a unique region of eight amino acids in the quinolone resistance-determining region in the gyrA gene in Neisseria gonorrhoeae as an indicator of resistance to fluoroquinolones. We sequenced that region by the Pyrosequencing technology in 46 N. gonorrhoeae strains and 11 urine samples positive in AMPLICOR N. gonorrhoeae polymerase chain reaction (Roche Diagnostics), with corresponding isolates of N. gonorrhoeae. The results showed that 28 samples with minimum inhibitory concentration (MIC) of ciprofloxacin >1 mg/L had mutations in positions 91 and 95. Fifteen samples with MIC 0.125-1.0 mg/L had either one or both of the mutations. The 14 susceptible samples had no mutations. The target region also discriminates N. gonorrhoeae from other species of Neisseria. Our conclusion is that gyrA is an indicator of resistance to ciprofloxacin in N. gonorrhoeae and sequencing by Pyrosequencing technology is a suitable tool for analysis of DNA in urine samples.     

Trend of antimicrobial resistance in Neisseria gonorrhoeae at New Delhi, India

We aim to monitor the trends of antimicrobial resistance in Neisseria gonorrhoeae and to compare the results of antimicrobial sensitivity by disc diffusion and minimum inhibitory concentration (MIC). Two hundred and eleven confirmed strains of N. gonorrhoeae were subjected to antimicrobial sensitivity testing by disc diffusion using penicillin, tetracycline, ciprofloxacin and ceftriaxone from 1995 to June 1999. Penicillinase-producing Neisseria gonorrhoeae (PPNG) were detected by lodometric method. Minimum inhibitory concentration was determined by E test. A low level of penicillin resistance and PPNG detected in 1996 was maintained over the years. Significant increasing trend of tetracycline and ciprofloxacin resistance with high MIC i.e. 2-96 microg/ml and 1-32 microg/ml respectively were found. Ceftriaxone was found to be the drug of choice, being 100% sensitive. Comparison of resistance pattern by the 2 tests showed satisfactory agreement. Emergence of penicillin, quinolone and tetracyline resistance in N. gonorrhoeae isolates from a major STD centre at New Delhi indicates the need for increased awareness, prudent use of antimicrobials, and evaluation of new antimicrobials for the treatment of gonorrhoea.     

A spontaneous mutant of Neisseria gonorrhoeae with decreased resistance to neutrophil granule proteins

We examined the resistance of Neisseria gonorrhoeae to proteins prepared from the granules of human polymorphonuclear neutrophils (PMNs). We found that nearly isogenic strains differing in lipopolysaccharide subunit molecular weight also differed in levels of resistance to crude granule extracts. N. gonorrhoeae strain WS1 was at least 10-fold less resistant than the parental strain FA 102 to granule extracts. Surprisingly, strain WS1 did not differ from FA 102 in resistance to two isolated antimicrobial proteins obtained previously from extracts of human PMN granules. We used strain WS1 in assays that detected antimicrobial proteins in granule extracts, and we obtained at least two proteins with apparent molecular masses of 24-25.5 kilodaltons that exerted potent in vitro antigonococcal activity. We found that the ED50 (concentration of protein required to kill 50% of gonococci) against the strain WS1 was approximately 0.006 microgram of protein/ml, whereas the ED50 against the parental strain (FA 102) was approximately 0.4 microgram of protein/ml. Accordingly, alterations in lipopolysaccharide structure apparently caused a 66-fold decrease in gonococcal resistance to granule proteins. Our data suggest that gonococcal resistance to oxygen-independent antimicrobial systems of human PMNs may, in part, depend on the availability of certain lipopolysaccharide domains involved in recognition of the antimicrobial granule proteins described in this report.     

龟头包皮炎患者淋病奈瑟菌分离与鉴定及其耐药机制研究

目的分离鉴定龟头化脓性包皮炎病原菌,检测分离菌株耐药性并了解其耐药机制。方法采取尿道分泌物及龟头脓包液标本,革兰染色镜检并采用Mycoplasma IST 2试剂盒检测支原体。上述标本接种哥伦比亚血平板、淋病奈瑟菌选择平板、酵母菌鉴定平板进行细菌分离培养,获得的菌落用VITEK 2-compact全自动细菌检测分析系统进行鉴定,另采用PCR检测上述标本及菌落的淋病奈瑟菌16SrRNA基因。采用K-B法检测分离菌株对5种常用抗生素的敏感性,采用β-内酰胺酶和超广谱β-内酰胺酶确证试验了解该菌株产酶情况,PCR检测该菌株耐药相关tetM、TEM、mefA和ermF基因。结果各标本支原体检测结果均为阴性。尿道分泌物标本分离培养结果均为阴性,龟头脓包液血平板和选择平板培养结果为阳性。VITEK 2-compact系统和16SrRNA-PCR检测结果显示分离菌株为淋病奈瑟菌。该菌株产β内酰胺酶且对青霉素G、环丙沙星、四环素耐药,其基因组携带tetM、TEM、mefA和ermF基因。结论淋病奈瑟菌可引起龟头化脓性包皮炎,该淋病奈瑟菌菌株多重耐药并与其携带的耐药基因密切相关。     

Fluoroquinolone-resistant Neisseria gonorrhoeae: the inevitable epidemic

The worldwide incidence of fluoroquinolone-resistant Neisseria gonorrhoeae has increased dramatically in the last few years. Single doses of fluoroquinolones can no longer be used to treat N gonorrhoeae infections acquired in the Far East, parts of the Middle East, the Pacific Islands, and parts of Western Europe and the United States. Although California and Hawaii account for most of the current United States cases, the increased incidence of FQR in some high-risk groups independent of geography heralds an imminent spread of drug-resistant strains throughout the rest of the population. The use of molecular tests has revolutionized the diagnostic field in STIs. The main limitation of their application in N gonorrhoeae testing has been the loss of culture specimens that allow antimicrobial sensitivity testing. New molecular methods have made it possible to detect antimicrobial resistance without the use of live organisms. These tests hold the promise of improving epidemiologic tracking of N gonorrhoeae drug resistance, leading to better patient management at the local level. The loss of fluoroquinolones limits available oral regimens to a single CDC-recommended antibiotic, cefixime. Oral, inexpensive, single-dose alternatives are needed to ensure continued therapeutic success.     

Quinolone resistance-determining region mutations and por type of Neisseria gonorrhoeae isolates: resistance surveillance and typing by molecular methodologies

Quinolone resistance is increasing rapidly in Neisseria gonorrhoeae and is a significant public health problem that requires ongoing surveillance. To examine the feasibility of molecular surveillance of quinolone resistance, and to further characterize an outbreak of resistant N. gonorrhoeae in Israel, the quinolone resistance-determining region (QRDR) sequences and the por types of 80 N. gonorrhoeae isolates were determined using molecular techniques. QRDRs of gyrA and parC were amplified by polymerase chain reaction and were sequenced directly. The por type was determined by checkerboard hybridizations performed using oligonucleotide probes to regions encoding 5 variable loops of the porin protein. All 42 ciprofloxacin-resistant (CipR) isolates had mutations in QRDRs of both gyrA and parC, and identical mutations were found in 93% of these isolates. One intermediately resistant isolate had 1 mutation in gyrA, and susceptible isolates showed no mutations. Forty isolates had 1 of 2 por types that differed only by an in-frame deletion in variable region 5; all but 1 of these isolates were CipR. QRDR sequencing and por type determination showed that the outbreak of CipR N. gonorrhoeae in Israel was clonal. QRDR mutations were consistent with those previously characterized; this indicates that DNA probes can be developed for rapid detection and surveillance of quinolone-resistant N. gonorrhoeae in settings in which nonculture diagnostic methods are used.     

Importance of drug resistance in gonococci: from mechanisms to monitoring

Neisseria gonorrhoeae isolates continue to develop an impressive arsenal of resistance mechanisms to antimicrobial agents, including resistance to some of the antibiotics presently recommended for the treatment of gonococcal infections.     

Defenses against oxidative stress in Neisseria gonorrhoeae and Neisseria meningitidis: distinctive systems for different lifestyles

Defenses against oxidative stress are crucial for the survival of the pathogens Neisseria meningitidis and Neisseria gonorrhoeae. An Mn(II) uptake system is involved in manganese (Mn)-dependent resistance to superoxide radicals in N. gonorrhoeae. Here, we show that accumulation of Mn also confers resistance to hydrogen peroxide killing via a catalase-independent mechanism. An mntC mutant of N. meningitidis is susceptible to oxidative killing, but supplementation of growth media with Mn does not enhance the organism's resistance to oxidative killing. N. meningitidis is able to grow in the presence of millimolar levels of Mn ion, in contrast to N. gonorrhoeae, whose growth is retarded at Mn concentrations >100 micromol/L, indicating that Mn homeostasis in the 2 species is probably quite different. N. meningitidis superoxide dismutase B plays a role in protection against oxidative killing. However, a sodC mutant of N. meningitidis is no more sensitive to oxidative killing than is the wild type. A cytochrome c peroxidase (Ccp) is present in N. gonorrhoeae but not in N. meningitidis. Investigations of a ccp mutant revealed a role for Ccp in protection against hydrogen peroxide killing. These differences in oxidative defenses in the pathogenic Neisseria are most likely a result of their localization in different ecological niches.     

Chromosomally mediated resistance in Neisseria gonorrhoeae in the United States: results of surveillance and reporting, 1983-1984

Between January 1983 and October 1984, 446 cases of infection due to chromosomally mediated resistance in Neisseria gonorrhoeae (CMRNG) were reported in 23 states. Eighty percent were detected as primary penicillin or ampicillin treatment failures. Gonococcal isolates were submitted from 175 (40%) for confirmation of resistance, susceptibility testing, gonococcal strain typing using monoclonal antibodies specific for outer membrane Protein I, and auxotyping. All were typed as Protein I serogroup IB (WII/WIII), and the majority were proline or prototrophic auxotypes. All were resistant in vitro to less than 1 microgram/ml of either penicillin or tetracycline. Comparing CMRNG with penicillinase-producing Neisseria gonorrhoeae (PPNG), we found that CMRNG were significantly more resistant to tetracycline and erythromycin, but PPNG were more resistant to penicillin (P less than .01). Because of increasing reports of gonococcal resistance in the United States, improved surveillance of clinical and laboratory resistance is needed in support of control and treatment recommendations for gonorrhea.     

A retrospective study of the clinical effectiveness of the treatment of genital co-infection with N. gonorrhoeae and C. trachomatis in Coventry

Concomitant infection of Neisseria gonorrhoeae and Chlamydia trachomatis is frequent and it is common practice to prescribe ancillary treatment for chlamydial infection when infection with N. gonorrhoeae is suspected or confirmed. In Coventry cases are treated as they are diagnosed. Our objective was to determine the clinical effectiveness of treating gonorrhoea and chlamydial infection separately in cases of co-infection. Case notes of co-infection with N. gonorrhoeae and C. trachomatis diagnosed in Coventry GU clinic from March 1989 to February 2000 were reviewed retrospectively. There were 1250 episodes of gonorrhoea, 4127 of chlamydial infections, and both infections were found in 332 cases. The two infections were treated in 322 cases and in 235 cases were treated separately. Ten cases did not come back for treatment of chlamydial infection, which is less than one case per year and 0.2% of total chlamydial infection in 11 years. On the other hand, 918 (73%) of total number of gonorrhoea patients did not have to take unnecessary treatment for chlamydial infection. In some clinical settings co-infection with N. gonorrhoeae and C. trachomatis could be treated separately with significant success and in the long run this might prevent development of antibiotic resistance of C. trachomatis infection.