An outbreak of multidrug resistant typhoid fever in Bangalore

Six hundred and eighty five blood cultures from children clinically diagnosed as enteric fever yielded 176 salmonella strains showing isolation success rate of 25.7%,S. typhi were 164 (93.2%),S. paratyphi A 5 (2.8%),S. choleraesuis 4 (2.3%) andS. typhimurium 3 (1.7%). Antibiogram of 164 isolates ofS. typhi showed triple drug resistance (TDR) in 156 strains (95.1%) to chloramphenicol, ampicillin and cotrimoxazole, and sensitivity of 90.2% and 95.1% to norfloxacin and ciprofloxacin respectively. Minimum inhibitory concentrations (MIC) of chloramphenicol were between 360 mcg and 640 mcg per ml. Phage types of 38 strains of TDRS. typhi were predominantly E1 and 0 with prevalences of 47.4% and 36.8% respectively in this region. All children with S.typhi isolates sensitive to quinolones inVitro responded well to these drugs with almost no relapse and hence, the newer generation of quinolones could be considered as the first choice in the primary treatment of enteric fever.     

Susceptibility of Group B Streptococci to 30 Antibiotic Including New Cephalosporins.

The in vitro susceptibility of 32 group B streptococci, isolated from infants with systemic infections, to 30 antibiotics including new cephalosporins was studied. Benzylpenicillin, having the minimal inhibitory concentration (MIC) of 0.063 μg/ml, was the most active agent among the penicillins tested, and ampicillin, having an MIC of 0.063–0.125 μg/ml, was almost as active as benzylpenicillin. Cephalosporins had a wide range of activities, but such cephalosporins as cefmenoxime (MIC of 0.032–0.063 μg/ml), cefuroxime, cefotaxime and ceftriaxone (MIC of 0.063–0.125 μg/ml), were equally or more active than benzylpenicillin or ampicillin. Latamoxef with an MIC of 8–16 μg/ml was least active among the cephalosporins tested. Kanamycin and amikacin, having MICs of 128 or more than 128 μg/ml, were far less active than gentamicin (MIC of 8–32 μg/ml) and tobramycin (MIC of 16–32 μg/ml). 31 and 72% of isolates were resistant to chloramphenicol and tetracycline respectively, but only one strain was resistant to erythromycin and lincomycin. The strains resistant to tetracycline and chloramphenicol were prevalent in the subtypes III and III/R group B streptococci.     

Salmonella infections in Kinshasa: the species involved and sensitivity to antibiotics]

292 Salmonella strains were isolated between 1986-1988 in the bacteriological unit of the Cliniques Universitaires de Kinshasa (Za?re). One hundred of these strains were isolated from pediatric samples. The most frequent strains were S typhi, S enteritidis and S typhimurium. S typhi strains were sensitive to all antibiotics tested. The other salmonella serotypes had an increasing resistance to several antibiotics especially ampicillin, streptomycin, tetracyclin and kanamycin. A significant decline was observed with chloramphenicol and sulfamethoxazol-trimetoprim. Stool-isolated strains from children were found to be resistant to all antibiotics in common use in 5/6 cases. In systemic Salmonella infection, treatment with chloramphenicol or sulfamethoxazole-trimetoprim plus gentamycin is probably preferable to any other antibiotic recommended for Salmonella infection.     

Antibiogram of enteropathogenic e. coli strains in infantile diarrhoea

Antibiotic sensitivity of 65 strains of enteropathogenic E. Coli, isolated from 194 cases of infantile diarrhoea was done. All the three serotypes 026, 086 and 055 Were found to be sensitive to garamycin and furazoladine, while most of these were resistant to chloramphenicol. 026 and 086 strains were resistant to neomycin also whereas it was effective against 055.     

Antibiotic Susceptibility of Type b Haemophilus influenzae and Streptococcus pneumoniae, and Antibiotic Concentration in Cerebrospinal Fluid

Antibiotic susceptibilities of 38 type b Haemophilus influenzae and 28 Streptococcus pneumoniae strains isolated from cerebrospinal fluid, blood and other specimens between 1973 and 1988 were studied. Minimal inhibitory concentrations (MICs) of ampicillin against 10 β-lactamase positive and 28 negative H. influenzae isolates were 32–64 and 0.25 μg/ml, respectively. The MIC of chloramphenicol against one of the β-lactamase positive H. influenzae strains was 8 but MICs against the rest of the organisms were 0.5–1 μg/ml. MICs of cefotaxime, ceftriaxone and cefuroxime against all H. influenzae strains were 0.016, 0.008 and 0.5 μg/ml, respectively. No S. pneumoniae isolates were resistant to penicillin G and MICs of this drug were 0.016–0.032 μg/ml. MICs of cefotaxime, ceftriaxone and cefuroxime against all S. pneumoniae strains were 0.016–0.032, 0.016–0.032 and 0.032–0.063 μg/ml, respectively. MICs of chloramphenicol against 15, 4 and 9 of S. pneumoniae isolates were 2, 8 and 16 μg/ml, respectively. Antibiotic concentrations in the cerebrospinal fluid of patients with bacterial meningitis after intravenous administration of ampicillin (50–70 mg/kgx4/day), penicillin G (31–63 mg/kgx4/day), cefotaxime (50 mg/kgx4/day) and chloramphenicol (25 mg/kgx4/day) were 4.70±1.83 (n=11), 0.57±0.32 (n=7), 4.97±2.60 (n=9) and 8.52±3.54 μg/ml (n=3), respectively. The initial choice of antibiotics in older children with bacterial meningitis is a combination of ampicillin (75 mg/kgx4/day) and cefotaxime (50 mg/kgx4/day) to cover ampicillin-resistant H. influenzae, S. pneumoniae , and Listeria monocytogenes in Japan. These antibiotics should be changed according to the causative organisms and their antibiotic susceptibilities.     

氯霉素、利福平对肺炎支原体的抗菌活性分析

目的探讨氯霉素、利福平对肺炎支原体(MP)的抗菌活性。方法对370例咽拭子标本进行MP分离培养,应用套式聚合酶链式反应(PCR)扩增MP种特异16SrRNA基因对临床分离株进行分子鉴定;通过药物敏感试验测定MP分离株的红霉素的最小抑菌质量浓度(MIC),应用套式扩增红霉素作用靶位23SrRNA基因,以鉴别敏感株和耐药株;应用药物敏感试验测定MP分离株的氯霉素、利福平的MIC。结果临床标本370例中分离MP50株。其中红霉素敏感株4株,耐药株46株。46株耐药株的红霉素作用靶位23SrRNA基因发生点突变,4株敏感株无点突变。所有MP分离株对氯霉素敏感,对利福平耐药。结论利福平对MP无效,氯霉素对MP红霉素敏感株及耐药株均有效。     

Multiple drug resistant non typhoidal salmonella spp associated with acute diarrheal disease

Rectal swabs/stool specimens from 115 children (0–5 years) suffering with acute diarrhea were screened for non typhoidal salmonella species. 7 (6%) patients were found to be positive for non typhoidal salmonella 4 (3.47%) were positive forS. paratyphi B and 3 (2.6%) were positive forS. typhimurium. Multidrug resistance was seen in 57 percent of the strains. All strains were sensitive to Ciprofloxacin. All strains were resistant to Ampicillin followed by Ciprofloxacin. All strains were resistant to Ampicillin followed by Gentamycin (43%), Kanamycin (43%), Tetracycline (43%), Streptomycin (28.5%) and Chloramphenicol (28.5%).     

儿童感染幽门螺杆菌对克拉霉素耐药情况及耐药机制初步研究

目的了解儿童幽门螺杆菌(Helicobacter pylor,Hp)对克拉霉素的耐药情况,探讨Hp对克拉霉素耐药性与23S rRNA基因突变的关系。方法。108例胃黏膜标本均取自2002年10月-2004年1月在浙江大学医学院附属儿童医院进行胃镜检查的患儿,经分离培养鉴定为Hp菌株后,分别采用E-test法和琼脂稀释法检测克拉霉素的最低抑菌浓度(minimum inhibitory concentration,MIC),确定Hp菌株对克拉霉素的耐药性。提取所有108株Hp基因组DNA进行PCR扩增,用限制性片段长度多态性(restriction fragment length polymorphism,RFLP)检测克拉霉素耐药菌株的点突变。结果Hp菌株对克拉霉素耐药率为14．8％(16／108)。16株耐药菌株23S rRNA V功能区PCR扩增片段RFLP分析,13株被BsaⅠ酶切,提示2144位点存在A→G点突变,3株被BbsⅠ酶切,提示2143位点存在A→G点突变,所有敏感菌株均不能被BsaⅠ和BbsⅠ酶切,提示无23S rRNA基因相应位点的点突变。同时本研究中并未发现突变形式与耐药程度的相关性。结论儿童Hp感染对克拉霉素耐药率较高;23S rRNA基因点突变是Hp对克拉霉素耐药的重要因素。耐药菌株存在A2144G和A2143G突变,以前者为主。     

杭州地区肺炎链球菌耐药性及遗传背景研究

目的 了解杭州地区肺炎链球菌儿童株的耐药性和流行特征。方法 用Kirby-Bauer法和Etest法对323株肺炎链球菌致病株和携带株进行耐药性分析,并对青霉素耐药株及部分相关菌株用BOX-PCR技术进行遗传背景研究。结果 青霉素敏感株136株,占42．1％,青霉素中介株和耐药株分别占40．2％和17．7％。青霉素的最低抑菌浓度范围为0．012～4．0μg／ml。所有菌株都对头孢噻肟和万古霉素敏感。90．7％的菌株对红霉素耐药,对四环素、甲氨苄啶一磺胺异嗯唑的耐药率也分别高达87．6％和48．6％,对氯霉素的耐药率为14．9％。多重耐药率61．0％,多数对红霉素、四环素和甲氨苄啶一磺胺异嗯唑联合耐药。99．4％的菌株对利福平和氧氟沙星敏感。BOX-PCR分析耐青霉素肺炎链球菌的临床株,未发现高度集中分布的BOX图谱,同一标本中分离到的表型不同的菌株或同一病人多次分离到的菌株BOX图谱可以不完全相同。结论 杭州地区肺炎链球菌耐药现象比较严重,头孢噻肟等第三代头孢菌素是治疗肺炎链球菌感染的理想药物。同一病人可同时或先后受不同肺炎链球菌克隆感染或定植。     

幽门螺杆菌对克拉霉素、阿莫西林、甲硝唑体外耐药性和敏感性的初步分析

目的　了解儿童幽门螺杆菌 (Helicobacerpylori,简称Hp)对克拉霉素、阿莫西林、甲硝唑体外敏感性和耐药性。方法　 4 4例Hp菌株取自 2 0 0 2年 10月～ 2 0 0 3年 11月在浙江大学医学院附属儿童医院进行胃镜检查患儿胃黏膜标本 ,分离培养获得 ,采用琼脂稀释法进行体外抗生素敏感试验 ,检测Hp菌株对 3种抗生素最低抑菌浓度 (MIC) ,并计算MIC50 和MIC90 值和Hp菌株对 3种药物的耐药率。结果　克拉霉素耐药率为 18 2 % (8/44 ) ,阿莫西耐药率为 9 1% (4 /44 ) ,甲硝唑耐药率为 31 8% (14 /44 ) ;其MIC值范围分别为 <0 12 5～ 6 4 μg/ml,<0 12 5～ 6 4 μg/ml和 <0 12 5～ 12 8μg/ml。克拉霉素半数抑菌浓度 (MIC50 )和 90 %抑菌浓度 (MIC90 )分别为MIC50 <0 12 5 μg/ml,MIC90 为 8μg/ml;,阿莫西林MIC50 <0 12 5 μg/ml,MIC90 为 0 5 μg/ml;甲硝唑MIC50 为 0 5 μg/ml,MIC90 为 12 8μg/ml。Hp菌株对克拉霉素耐药率高于国内成人水平 ,对甲硝唑耐药率则低于成人水平 ,但耐药菌株MIC值和MIC90 均在较高水平。 3株Hp菌株对阿莫西林、克拉霉素和甲硝唑同时耐药 ,多重耐药率为 6 8% (3/44 )。结论　儿童Hp对甲硝唑耐药率较高 ,对克拉霉素耐药率较成人高 ,已有耐阿莫西林菌株 ,部分菌株多重耐药。     

Antibiotic susceptibilities of 120 strains of Staphylococcus aureus isolated from patients at a Children's Hospital. Decline of hospital staphylococci as compared with staphylococci in outpatients. A reversal.

The antibiotic sensitivities of 120 strains of Staphylococcus aureus isolated from both hospitalized patients and outpatients at Children's Memorial Hospital, Oklahoma City were studied. The proportions of strains resistant to the commonly used antibiotics were considerably lower than that found by other workers in earlier years, except for penicillin G. Of the 120 strains, 98 (81.7%) were resistant to penicillin G, 13 (10.8%) to tetracycline, 9 (7.5%) to erythromycin, and 3 (2.5%) to clindamycin. No strains resistant against cephalothin, chloramphenicol, gentamicin, or oxacillin were found. Sixteen strains (13.3%), of which 5 were inpatient strains and 11 were outpatient strains, were found to be resistant to more than one drug. Phage group 1 or type 80/81 staphylococci were not found among multiple resistant strains from hospitalized patients.     

儿童肺炎链球菌耐药性与pbp2b基因RFLP和PFGE图型分析

目的　监测肺炎链球菌对青霉素和其他抗生素的耐药情况 ;分析pbp2b基因扩增产物图谱与青霉素耐药性的相关性 ;对 3 1株青霉素耐药菌株进行血清分型 ;分析血清型 2 3F和血清型 6的青霉素耐药菌株的脉冲电场凝胶电泳 (PFGE)图型 ,初步了解北京地区耐药菌株分子流行病学上的特点。方法　 ( 1)抗生素药物敏感试验 ;( 2 )用聚合酶链反应 (PCR)和限制性内切酶片段长度多态性分析 (RFLP)方法 ,分析pbp2b基因扩增产物图谱与青霉素耐药性的相关性 ;( 3 )使用乳胶凝集的方法 ,对 3 1株青霉素耐药菌株进行血清分型 ;( 4 )使用PFGE图型方法分析 6株血清型 2 3F和 3株血清型 6的青霉素耐药菌株流行病学上的基本特性。结果　 ( 1)对青霉素的耐药性由 1997年 9 9%上升到 2 0 0 0年 14 6% (P >0 0 5)。对红霉素、复方磺胺甲基异唑和氯霉素耐药性分别由 1997年76 8%、74 7%和 2 2 6%上升到 2 0 0 0年的 87 4%、88 3 %和 40 8% (P <0 0 5) ;( 2 )通过PCR和RFLP方法分析青霉素耐药菌株和青霉素敏感菌株表明 ,pbp2b基因扩增图谱与青霉素耐药性之间有较好的相关性 ;( 3 )对 3 1株青霉素不敏感肺炎链球菌 (PRSP)做了血清型 2 3F和 6分型。前者为 6株 ( 19% ) ;后者为 3株 ( 9% )。 6株血清型 2 3F肺炎链球菌均为低水平     

Multidrug resistant typhoid fever: therapeutic considerations.

Forty six blood culture positive cases were studied during the current outbreak of multidrug resistant typhoid fever (MRTF). The present outbreak was caused by E1 phage type and organisms were resistant to all commonly used drugs for the treatment of typhoid fever, viz., chloramphenicol (78%), co-trimoxazole (76%) and ampicillin (68%). Treatment failures with chloramphenicol (45.5%) corroborated well with in vitro resistance. No treatment failure was seen with chloramphenicol and ceftriaxone, when these drugs were used in cases infected with sensitive strains. Among the alternative drugs used in cases with in vitro sensitivity, successful clinical response was seen with ceftriaxone (4/4) and cefotaxime (8/9) as compared to cephalexin (3/5) or a combination of cephalexin and furazolidone (9/12).     

Penicillin-intermediate pneumococci in a children's hospital

During the three-year period from 1981 to 1984, all clinical isolates of Streptococcus pneumoniae were screened for resistance to penicillin in the clinical bacteriology laboratory at The Children's Hospital of Alabama, Birmingham. Twenty-eight of 828 isolates were presumed resistant by disk diffusion testing with 1-microgram oxacillin disks (zone diameter, less than 20 mm). Seventeen of the 28 (61%) were found to be intermediately sensitive to penicillin by a conventional agar dilution method. Penicillin-intermediate strains had a minimal inhibitory concentration of 0.125 to 0.5 mg/L; no penicillin-resistant (minimal inhibitory concentration, greater than 1 mg/L) strains were encountered. The prevalence of penicillin-intermediate strains was thus 17 of 828 isolates, or 2.1%. These strains were also examined for susceptibility to ampicillin, vancomycin, cefotaxime, and chloramphenicol. We present the clinical features of 17 patients with disease due to penicillin-intermediate pneumococci.     

Plasmid mediated enterotoxin production and drug resistance amongstEscherichia coli from cases of infantile diarrhea

Seventy enterotoxigenic Esch. coli strains (18LT+; 46ST+ and 6LT+ST ^†) isolated from infants and children with acute diarrhea were studied for the prevalence of R factor and also for enterotoxin (Ent^†) plasmid transfer. These strains were received at the National Salmonella and Escherichia Centre, Central Research Institute, Kasauli during 1981. Sixty one strains were found to be resistant to two or more drugs and 9 were sensitive to all the drugs. Of the total, 24 (34·2%) strains showed the presence of conjugative plasmid; of these 10 (41%) strains showed transfer of Ent^† plasmid, of the 24 strains 6 strains were positive for LT and 18 for ST. Of the 6 LT^† strains which showed presence of R factor, Ent⁺ plasmid could be demonstrated in four strains and out of 18 ST^† strains Ent^† plasmid could be transferred in six Esch. coli strains.     

Ciprofloxacin in typhoid fever

The study covers 78 children with typhoid fever who were hospitalized in April & May 1990. Serious complications were present in 32% (toxemia 22%, ileus 25% and myocarditis 8%). Blood cultures were positive in 30 of 49 tested. Others were diagnosed by positive Widal test.In vitro cultures ofS. typhi were resistant to chloramphenicol (90%), ampicillin (93%) and co-trimoxazole (97%). However all were highly sensitive to ciprofloxacin and moderately sensitive to cephalexin and gentamycin. Ciprofloxacin alone or in combination was given in 73 of the 78 children and found to be remarkably effective in controlling the disease and preventing relapse. No serious side effects were noted. The cohort is being followed up for possible long term adverse effects.     

In vitro antibiotic sensitivity pattern of common bacterial isolates from cases of acute bacterial meningitis with special reference to ceftriaxone

Ceftriaxone (RO 13-9904) has only recently been introduced in Benghazi and many parts of the word. We determined itsin vitro antibacterial activity against the primary aetiological agents of childhood meningitis in Benghazi, that included eighteen (23.3%) strains ofH. influenzas, 17 (22.1%) ofStr. pneumoniae and 1 (1.3%) ofN. meningitidis isolated from 77 cases of acute purulent meningitis above the age of neonatal period. All strains ofH. influenzae. Str. pneumoniae andN. meningitidis were sensitive to ceftriaxone and showed wide zones of inhibition by the disc diffusion technique of Kirby-Bauer. Ampicillin and chloramphenicol resistance was observed forH. influenzae (23% and 11% respectively), andStr. pneumoniae (12% and 0% respectively), in addition, 18% of strains ofStr. pneumoniae showed resistance to penicillin. The broad spectrum activity of ceftriaxone has been confirmed for our locality and this finding, together with its exceptionally long half-life, excellent penetration into the C.S.F. and ease of administration (single daily dose) warrants it as the drug of choice in empherical treatment of cases of acute bacterial meningitis in children in Benghazi and in cases where resistance to ampicillin and chloramphenicol are found on subsequent testing.     

Antimicrobial resistance of nasopharyngeal isolates of Streptococcus pneumoniae in healthy carriers: report of a study in 5-year-olds in Marcory, Abidjan, Côte d'Ivoire

The increasing prevalence of antibiotic-resistant Streptococcus pneumoniae is of growing public health concern. The aim of this study was to assess resistance rates of S. pneumoniae to penicillin and other antimicrobial agents. Between November 1997 and February 1998 in a community health centre in Marcory, an Abidjan suburb, 138 S. pneumoniae strains were isolated from the nasopharynxes of 218 apparently healthy children aged 3-60 months. The sensitivity of the isolates was tested using the Kirby-Bauer method. In isolates with a possibly abnormal sensitivity to the Kirby-Bauer test, minimum inhibitory concentrations (MIC) were estimated using the E-test. Antimicrobials tested included penicillin G, amoxycillin, cefotaxime, cotrimoxazole, tetracycline, chloramphenicol, erythromycin, rifampicin and vancomycin. Twelve of 108 isolates (8.7%) had reduced sensitivity to penicillin G, and in three of them the MIC for penicillin reached at least 2 micrograms/ml. Resistance to amoxycillin and cefotaxime was lower than to penicillin (2.2%). With regard to cotrimoxazole, 37% were moderately resistant and 15.2% highly resistant. The lowest resistance rate observed was to rifampicin (2.2%) and the highest was to tetracycline (57.2%). Rates of resistance to erythromycin and chloramphenicol were 11.6% and 2.9%. All strains were sensitive to vancomycin. Multidrug resistance (MDR) was detected in 9.4% of S. pneumoniae isolates. In children, epidemiological surveillance of resistance can be monitored by bacteriological surveys, as shown in this study.     

Urinary triact infections in childhood

Summary 1550 samples of urine from children suspected to have urinary tract infection were cultured. Esch. coli was the commonest organism found. The next in frequency were coagulase positive staphylococci,B. proteus, Strep. faecalis, Pseud. pyocyaneus and klebsiella. Mendalamine was found to be the most effective antiseptic against urinary pathogens isolated in the present study. However, chloramphenicol remains the drug of choice for coagulase positive staphylococci. Gentamicin and colomycin should be used against resistant strains ofEsch. coli andPseud. pyocyaneus respectively.     

Comparative efficacies of aztreonam and chloramphenicol in children with typhoid fever

We compared aztreonam with chloramphenicol in a randomized trial involving the treatment of 36 children with typhoid fever. Eighteen children were randomized to receive aztreonam, 150 mg/kg/day intravenously, and 18 to receive chloramphenicol, 100 mg/kg/day orally. On entry in the study the clinical characteristics of the two treatment groups were comparable. The duration of therapy was 14.9 +/- 3.6 days for the aztreonam group and 12.8 +/- 2.6 days for the chloramphenicol group. The mean duration of fever was 5.9 +/- 3.1 days and 4.05 +/- 2.1 days for aztreonam and chloramphenicol groups respectively (P greater than 0.05). Clinical cure was observed in all patients treated with aztreonam and in 17 of 18 children given chloramphenicol; one patient died in the latter group. There were no relapses in either group. We observed clinical adverse reactions during the treatment with aztreonam in 2 patients. All strains of Salmonella typhi were susceptible to aztreonam, 1 strain was resistant to chloramphenicol and 3 strains were resistant to ampicillin. Aztreonam appears to be a satisfactory alternative to chloramphenicol in cases of typhoid fever caused by resistant strains or when chloramphenicol is contraindicated.