1998～2002年广州地区淋球菌对抗生素耐药性的变迁

目的 :了解 1998～ 2 0 0 2年广州地区淋球菌对 5种抗生素的耐药性的变迁及产青霉素酶淋球菌(PPNG)和高水平耐四环素淋球菌 (TRNG)的流行状况。方法 :用琼脂稀释法测定最低抑菌浓度 (MIC)以及用纸片碘量法检测β-内酰胺酶。结果 :60 3株淋球菌检出 PPNG 64株 (10 .6% )、TRNG 83株 (13 .7% ) ,1998～ 2 0 0 2年 ,PPNG、TRNG流行率及环丙沙星耐药率 ,经μ检验 ,P<0 .0 1,差异有显著性。头孢曲松、壮观霉素未发现耐药菌株 ,壮观霉素抗菌活性最强。结论 :持续监测淋球菌的耐药性十分重要     

杭州市淋病奈瑟菌质粒酶切图谱分析研究

目的 :了解杭州市淋病奈瑟菌质粒携带及质粒谱型分布情况。方法 :采用碱裂解法对门诊 2 0 0 0年 1月～ 2 0 0 1年 10月分离的 2 0 7株淋病奈瑟菌进行了质粒抽提及质粒谱分型研究 ,并对菌株的青霉素耐药现象和耐药性质粒的关系进行探讨。结果 :2 0 7株淋病奈瑟菌中 194株 (93 .7% )检见质粒带 ,其中含一条质粒带的 112株 (5 4.11% ) ,含两条质粒带的 12株 (5 .8% ) ,含三条带的 70株 (3 3 .82 % ) ,尚有 13株(6.2 8% )未检测到质粒。以 E.coli V5 17细菌质粒作分子量标准 ,测得这些分子量分别为 2 .6、4.5、和 2 4.5Md。质粒谱型以 2 .6 4.5 2 4.5 Md(3 3 .82 % )多见。结论 :杭州地区质粒酶切图谱的分析研究有助于淋病的治疗和防治 ,这将对该地区淋病奈瑟菌的分子流行病学调查和淋病监控提供依据     

淋病奈瑟菌临床菌株porB基因分型及其突变与耐药相关性研究

了解淋病奈瑟菌临床菌株porB基因型及其产物120和121位氨基酸突变与耐药的相关性。采用多重PCR(mPCR)检测淋病奈瑟菌临床菌株porB基因型,扩增产物测序后分析其编码蛋白的120和121位氨基酸突变情况,二倍平皿稀释法检测临床菌株对青霉素和四环素的耐药性。184株淋病奈瑟菌临床菌株中,99.5%(183/184)检出porB基因,其中61株(33.3%)为porB1A基因型,122株(66.7%)为porB1B基因型。122株porB1B基因型菌株中,117株(95.9%)porB基因120和/或121位氨基酸发生突变,5株(4.1%)porB1B及所有porB1A基因型菌株porB基因120和/或121位氨基酸未突变。117株porB基因120和/或121位氨基酸突变的porB1B基因型菌株中,97.4%(114/117)和95.7%(112/117)分别对青霉素和四环素耐药,2.6%菌株(3/117)对青霉素和四环素敏感。61株porB1A基因型菌株中,仅有2株(3.3%)对青霉素和四环素耐药。研究中采用的mPCR能快速、准确地对淋病奈瑟菌临床菌株porB基因进行分型,这些菌株主要携带porB1B基因且该基因型菌株对青霉素和四环素耐药率显著高于porB1A基因型(P<0.01),该耐药性与porB1B基因120和/或121位氨基酸突变密切相关。     

医院感染葡萄球菌菌种变迁与耐药性近况

目的：了解近9年来医院感染葡萄球菌菌种的变迁与近3年来葡萄球菌药状况。方法：1993年1月至2001年12月我院传染病科等13科室住院病人的各种标本采用血琼脂培养,所分离的葡萄球菌采用美国DADE公司生产的MICROSCAN WALKAY-40全自动微生物分析仪鉴定到种及其亚种。药敏试验药物有青霉素、苯唑西林、氨苄西林、哌拉西林、阿莫西林／克拉维酸（阿莫仙）、头孢唑啉、头孢噻肟、头孢哌酮／舒巴坦（舒普深）、庆大霉素、复方新诺明、环丙沙星、氧氟沙星、利福平、万古霉素、红霉素、林可霉素、四环素、伊米配能／西司他丁（泰能）共18种。采用液体稀释法测定每株葡萄球菌对受试药物的最小抑菌浓度（MIC）,操作按说明书进行。质控菌ATCC25923。依据新近NCCLS标准判读结果。结果：1993年至1998年分离的葡萄球菌中,金黄色葡萄球菌（金葡萄）占71.43%,凝固酶阴性葡萄球菌（CNS）占28.57%,包括表皮葡萄球菌（表葡菌）、腐生葡萄球菌、里昂葡萄球菌和头状葡萄球菌4种。1999年至2001年分离的424株葡萄球菌中,金葡菌仅占29.01%,CNS增至13种,占70.995,以表葡菌、溶血葡萄球菌、松鼠葡萄球菌为主。近3年来分离的各种葡萄球菌甲氧西林耐药率在73.03%-100%之间,除对舒普深、复方新诺明、利福平和万古霉素较敏感外,对其余抗菌药物的耐药率均超过60％,以金葡菌、溶血葡萄球菌、松鼠葡萄球菌的耐药率为最高。MRS耐药率普遍高于MSS,且均呈多重耐药。5.42%(23/424)菌株万古霉素MIC＞16mg/L,除1株为MSCNS外,其余22株均为MRS。结论：3年来医院感染葡萄球菌菌种构成比发生了显著变化,以CNS为主。对抗菌药物呈多重耐药,部分菌株对万古霉素敏感性降低,应予警惕。     

淋病奈瑟球菌的耐药性检测

目的了解淋病奈瑟球菌对临床常见药物的耐药性。方法采用琼脂稀释法测定13种抗菌药物对35株淋病奈瑟球菌的MICs;Nitrocefin(头孢硝噻酚)纸片检测β-内酰胺酶,并采用PCR测定其基因型。结果淋病奈瑟球菌对青霉素、四环素、环丙沙星与头孢呋辛的耐药率分别为65．7％、60．0％、88．6％与14．3％,对第3、4代头孢菌素、大观霉素非常敏感,耐药率均为0％;42．9％的菌株产生TEM型β-内酰胺酶。结论淋病奈瑟球菌对青霉素、四环素类和氟喹诺酮类的耐药性高,治疗宜选用第3、4代头孢菌素和大观霉素等,同时加强耐药性监测。     

Sigma B对单核细胞增生李斯特菌耐受抗生素作用的影响

单核细胞增生李斯特菌是重要的革兰阳性食源性致病菌。近年来的报道显示出该菌耐受抗生素的能力有不断增强的趋势,为了探讨其耐药机制,对Sigma B（σB,李斯特菌中应对环境胁迫的主要调控因子）在抗生素耐受性中的作用进行了初步研究。检测和比较单核细胞增生李斯特菌标准菌株EGDe和其σB缺失突变菌株EGDeΔsigB对盘尼西林青霉素、氨苄西林青霉素、利福平、硫酸庆大霉素、四环素盐酸和红霉素6种抗生素的最小抑菌浓度（MIC）;在测定的MIC的基础上,利用MTT（噻唑蓝活体染色法）法比较EGDe和EGDeΔsigB在1×MIC、2×MIC和8×MIC的氨苄西林青霉素、红霉素和利福平3种抗生素中的生长活性。EGDe对盘尼西林青霉素（0.16μg/mL）、四环素盐酸（0.25μg/mL）和硫酸庆大霉素（0.5μg/mL）的MIC高于EGDeΔsigB（分别为0.08、0.125和0.125μg/mL）;而对氨苄西林青霉素、红霉素和利福平的MIC 2种菌株没有差别,分别为0.19、0.125和0.032μg/mL;与EGDe相比,EGDeΔsigB在氨苄西林青霉素、红霉素和利福平培养基中的生长活性较差,对抗生素的抑制更为敏感,而且随着这3种抗生素浓度的增加,其抑制程度也随之增强。Sigma B在单核细胞增生李斯特菌对抗生素的耐受中起到重要调节作用。     

洋葱伯克霍尔德菌对哌拉西林/他唑巴坦MIC值变迁的4年监测

目的了解浙江地区4年分离的洋葱伯克霍尔德菌对哌拉西林-他唑巴坦的MIC值变迁,以利于临床对该抗生素在抗感染中更合理的应用。方法先用VITEK-32型配套的药敏检测卡GNS-120检测2000～2003年临床分离的洋葱伯克霍尔德菌对哌拉西林-他唑巴坦的敏感性。对不耐药的菌株进一步用哌拉西林-他唑巴坦E-试条进行MIC检测,并统计其累积的MIC值变化情况。结果2000—2003年,洋葱伯克霍尔德菌对哌拉西林．他唑巴坦的耐药率分别为：40．5％,42．9％,40．6％,41．2％。对分离到不耐哌拉西林．他唑巴坦的100株菌（2000～2003年分别为21株、21株、22株、36株）进行MIC值检测,其累积的MIC百分率,M1C值≤4分别为：47．6％,42．9％,45．5％,36．I％;MIC值≤8分别为：66．7％,52．4％,54．5％,47,2％;MIC值≤16分别为：76．2％,66．7％,63．6％,52．8％。结论4年中临床分离的洋葱伯克霍尔德菌对哌拉西林-他唑巴坦的耐药率虽然变化不大,但其不耐药菌株对哌拉西林-他唑巴坦的累积MIC百分率降低较为明显,表明洋葱伯克霍尔德菌对哌拉西林-他唑巴坦的耐药性存在有增加的趋势,应引起临床的重视。     

2010年广州地区淋球菌耐药监测结果分析

目的了解广州地区淋球菌对抗生素耐药性的变化及PPNG和TRNG的流行趋势。方法用琼脂稀释法测定头孢曲松、大观霉素、环丙沙星、阿奇霉素和四环素的最低抑菌浓度（MIC）;用纸片碘量法检测β-内酰胺酶。结果83株淋球菌检出PPNG24株（28．9％）、TRNG50株（60．2％）、环丙沙星耐药率高达98．8％,高度耐药株（MIC≥16mg／L）43株（51．8％）,而76株淋球菌中阿奇霉素耐药株11株（14．5％）,均未出现对头孢曲松、大观霉素耐药的菌株,抗菌活性强。结论合理规范使用抗生素及动态监测淋球菌耐药性变迁是临床减少淋球菌耐药菌株出现的有效办法。     

郴州地区淋病奈瑟菌耐药性特点分析

目的 了解郴州市区域内病奈瑟菌耐药性特点,为临床用药提供依据。方法 收集郴州市区域内12家医院门诊病人泌尿生殖道分泌物中分离的255株淋球菌,并作为药敏试验,分析其特点。结果 255株淋球菌对青霉素100％耐药,对复方新诺明、氨苄、青霉素、四环素等耐药严重,同时耐毒霉素、头孢三嗪、环丙沙星等交叉耐药现象严重。结论 临床上治疗淋病须以体外药敏试验为依据用药,以提高疗效和减少耐药菌株的产生。     

细胞壁缺陷型淋病奈瑟菌cppB基因的检测

目的：了解细胞壁缺陷对淋病奈瑟菌隐蔽性质粒B基因（cppB）的影响。方法：用青霉素诱导林病奈瑟菌成L型,以非高渗液体培养基传代培养并获得L型纯培养物,用cppB基因特异性引物以聚合酶链反应（PCR）检测不同代次稳定L型纯培养物的cppB基因。结果：淋病奈瑟菌细菌型及其传1-4代的L型培养物具有cppB基因,传5代后的L型培养物不能检出cppB基因。结论：细胞壁缺陷可造成淋病奈瑟菌隐蔽性质粒丢失,导致cppB基因PCR检测漏诊。     

Long-term antibiotic susceptibility pattern of strains of Neisseria gonorrhoeae isolated in Czechoslovakia in the years 1957-1982

Over the past 25 years a total of 7492 strains of Neisseria gonorrhoeae have been isolated in Czechoslovakia, mainly in Prague (64%). All these strains have been tested for susceptibility to the following antibiotics: penicillin G, ampicillin, tetracycline, spectinomycin, erythromycin, doxycycline, kanamycin, rifampin, chloramphenicol, gentamicin, cephalothin, cephaloridine, lincomycin and clindamycin. In addition, seven derivatives of newer antibiotics of penicillin and cephalosporin series were tested in 1981. The study showed that in 1957 the MIC of 0.03 units of penicillin per ml was effective against 95% of strains, but in 1981 only 37% of isolates were sensitive to this concentration. The first gonococcal strains with the MIC value of 4.0 units/ml to penicillin were detected in 1981. This tendency towards decreased gonococcal susceptibility to benzylpenicillin is alarming. Over the last eight years there have been described sporadic isolations of strains relatively resistant to tetracycline (MIC = 8.0 mg/l). The susceptibility to spectinomycin has been tested in over 4000 gonococcal strains, since 1967. The test showed that this antibiotic remained highly effective against the gonococcal infection with over 95% of gonococci with the MIC value of 16.0 mg/l. No fully spectinomycin resistant strains have been found. Penicillin G as well as spectinomycin and cefotaxim are still considered the antibiotics of the first choice in the treatment of gonorrhoea. The alternative antibiotics may include cefuroxim, chloramphenicol and, in cases of sensitive strains, tetracyclines.     

Study of five penicillinase producing Neisseria gonorrhoeae isolated in Italy

Five penicillinase producing Neisseria gonorrhoeae (PPNG) were isolated from urethral specimens of men admitted to the "Santa Chiara" Hospital (Trento, Italy). All strains proved to be resistant to penicillin and ampicillin, and sensitive to cefuroxime, erythromycin, tetracycline, spectinomycin, nalidixic acid and ciprofloxacin. PPNG plasmid profiles showed that four of the isolates carried the 3.2 MDa "Africa" plasmid and one the 4.5 MDa "Asia" plasmid, the two well-known phenotypes reported in the USA and Europe as well as in Asian and African countries. Membrane matings were performed using N. gonorrhoeae carrying the 24.5 MDa conjugative plasmid as donors and E. coli K12 J 53 as recipient. The transfer of beta-lactamic antibiotic resistance was supported by the presence of 4.5 or 3.2 MDa plasmid bands and by beta-lactamase production in the transconjugants. Restriction analysis of Asian and African plasmids is reported.     

Influence of an extended incubation period on values of minimum inhibitory concentrations of antibiotics in Stenotrophomonas maltophilia clinical strains

In 106 Stenotrophomonas maltophilia clinical strains the susceptibility to 19 kinds of antibiotics was tested by the broth dilution micromethod at 24 h and 48 h incubation. Isolated strains demonstrated the lowest frequency of resistance to cotrimoxazole (7.5% of resistant strains at 24 h incubation and 18.9% at 48 h), ofloxacin (13.2% and 30.2%), ciprofloxacin (19.8% and 50.9%) and to cefoperazone/sulbactam (20.8% and 37.7%). The smallest growth of the number of resistant strains after extended incubation was recorded in gentamicin (by 10.4%), ceftazidime (by 11.3%) and cotrimoxazole (by 11.4%). On the contrary, the largest growth of resistance was demonstrated in cefoperazone and ciprofloxacin (by 31.1%). Average values of the growth of minimum inhibitory concentrations (MICs) were lowest in ciprofloxacin and ofloxacin (2.3 times) and highest in piperacillin/tazobactam (4.5 times) and piperacillin (5.0 times). As far as the stability of MIC is concerned, the largest occurrence of strains with the MIC growth doubled as a maximum was found in ceftazidime (78.4%), ofloxacin (76.1%) and ciprofloxacin (75.3%), the smallest in piperacillin/tazobactam (43.2%) and piperacillin (38.9%). The importance of incubation extended to 48 h during the testing of S. maltophilia strains was noted for correctly setting their susceptibility to antibiotics.     

Changes of methicillin-resistant Staphylococcus aureus (MRSA) phagotypes in Gdansk in 1990-1998

The aim of the study was the assessment of changes in the occurrence of various MRSA phagotypes in hospitals in the Gdańsk area in 1990-1998. The study was carried out on 175 MRSA strains: 45 strains isolated in 1990-1995 and 130 in 1997-1998. The studied staphylococci were obtained from various clinical materials from patients in 18 hospitals. Phagotyping was done with a set of 10 experimental phages from MRSA strains obtained from the Central Public Health Laboratory in London. Drug-resistance was determined by the disc-diffusion method and in case of strains with medium susceptibility to fusidic acid the minimal inhibitory concentration (MIC) was determined by serial dilutions on solid medium. The study showed among MRSA strains isolated in 1997-1998 a new, previously not known strains with phage pattern MR25/M5 predominated (57.7%). Its presence was found in various hospitals in that area. MRSA belonging to MR25/M5 phagotype were mostly resistant to doxycycline, gentamycin, erythromycin, clindamycin, ciprofloxacin, rifampicin and were resistant or only had medium susceptibility to fusidic acid. The MIC values for strains with medium susceptibility to fusidic acid (4-8 micrograms/ml) showed an evident decrease of the susceptibility to this antibiotic, formerly common in MRSA. At the same time, in 1997-1998 a considerable decrease was observed of the number of MRSA strains belonging to MR8/MR12/MR25/30/33/38/M5/622 phagotype (from 31.1% to 0.8%), and disappearance of strains with phagotypes MR25/56B/M3 and MR8/MR25/622, which in 1990-1995 accounted for 15.6% of the studied staphylococci.     

In vitro anti-Neisseria gonorrhoeae activity of Terminalia macroptera leaves

We used the agar dilution method to evaluate the antibacterial effect of Terminalia macroptera leaf (Tml) extract against nine reference and clinical Neisseria gonorrhoeae strains, including penicillin- and tetracycline-resistant and -susceptible strains. Tml possesses anti-N. gonorrhoeae activity against all of the strains and the minimum inhibitory concentrations (MIC) were between 100 and 200 microg ml(-1). We then used a liquid-liquid partition method to divide the Tml extract into five fractions and determined the anti-N. gonorrhoeae activity of each of the fractions. All of the fractions showed antibacterial activity. The most active one was identified as the diethyl ether fraction and had MIC values of between 25 and 50 microg ml(-1) against all of the strains.     

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.     

Intrinsic penicillin resistance in penicillinase-producing Neisseria gonorrhoeae strains

The minimal inhibitory concentrations (MICs) of ampicillin for fifty strains of beta-lactamase-producing Neisseria gonorrhoeae (PPNG) isolated in Japan ranged from 1.56 to 200 micrograms/ml, and all the strains harbored a 4.5 megadalton plasmid. These strains were classified into two groups: dicloxacillin-susceptible (28%) and -resistant group (72%). A linear correlation was found in the dicloxacillin-susceptible strains between their beta-lactamase activity and the susceptibility to ampicillin, but not in the dicloxacillin-resistant strains. This suggests that the high ampicillin resistance in PPNG is due not only to acquiring the beta-lactamase producing plasmid, but also to some intrinsic resistance of the strains. To investigate a cause of the high ampicillin resistance, the beta-lactamase-producing plasmid, pTMS1, was transferred by conjugation to a penicillin-susceptible gonococcal strain as well as to its isogenic multiply antibiotic-resistant transformants, and the susceptibility of the transconjugants to ampicillin was determined. Acquisition of pTMS1 by a penicillin-susceptible strain resulted in a 32-fold increase in resistance to ampicillin, whereas the increase was 128-fold for its isogenic strains which contain some chromosomal mutations. These results suggest that reduced permeability of the outer membrane to ampicillin underlies the high ampicillin resistance of PPNG.     

广州地区74株淋球菌耐药性结果分析

目的了解广州地区淋球菌对抗生素的耐药性及PPNG和TRNG的流行状况。方法用琼脂稀释法测定最低抑菌浓度（MIC）;用纸片碘量法检测β-内酰胺酶。结果74株淋球菌检出PPNG31株（41．9％）、TRNG19株（25．7％）、环丙沙星耐药率达97．3％,高度耐药株（MIC≥16mg／L）22株（29．7％）,未发现对头孢三嗪、壮观霉素耐药的菌株,且抗菌活性最强。结论持续监测淋球菌的耐药性十分重要。     

In vitro antimicrobial activities of new quinolone antibiotics against Mycoplasma pneumoniae]

The antimicrobial activities against Mycoplasma pneumoniae of new quinolones (temafloxacin, ofloxacin, ciprofloxacin, enoxacin, and norfloxacin) and of tetracyclines and macrolides as controls were compared. Among new quinolones, temafloxacin, ofloxacin, and ciprofloxacin were more active than enoxacin and norfloxacin against fifty strains of Mycoplasma pneumoniae, giving MIC50 and MIC90 significantly lower than those of the latter two, by the agar-dilution method. The three more active antibiotics in the above assay were then determined for MICs and MBCs by the broth-dilution method. The MICs of every antibiotic except erythromycin determined by both the methods were very similar each other. The MICs of erythromycin determined by the broth-dilution method were ten-times higher than those determined by the agar-dilution method. Temafloxacin and ofloxacin gave MBCs only about four-times higher than MICs, whereas ciprofloxacin, minocycline, erythromycin and josamycin gave MBCs as much as 15 to 1,000-times higher than MICs. From the MICs and MBCs determined by the two assay methods, it is apparent that temafloxacin and ofloxacin, and to a less extent ciprofloxacin, have more potent mycoplasmacidal activities than do macrolides and tetracyclines.