Regional Medical Research Centre, ICMR, Port Blair, India.
Indian J Med Res. 2012 Mar;135(3):365-70.
BACKGROUND & OBJECTIVES: Shigellosis is known to be a major cause of acute childhood diarrhoea in Andaman & Nicobar Islands, India. Rapid emergence of antibiotic resistance warrants continuous monitoring of sensitivity pattern of bacterial isolates. We report here the salient findings of an ongoing study on shigellosis in Andaman Islands, India, with regards to change in drug resistance pattern during the past one decade.
During 2006-2009, stools samples from 412 paediatric diarrhoea patients were collected and processed for isolation and identification of Shigella spp. Susceptibility to 22 antimicrobial drugs was tested and MICs were determined for 3 rd generation cephalosporins, quinolones, amoxicillin-clavulanic acid combination and gentamicin. Drug susceptibility pattern of these isolates were compared with that of 33 isolates obtained during 2000-2002.
Shigella isolates were recovered from 50 of 412 stool samples processed. Resistance to ampicillin, nalidixic acid, tetracycline and ciprofloxacin was observed in 100, 96, 94 and 82 per cent of the isolates, respectively. The frequency of resistance to these drugs was significantly (P<0.001) higher than that observed during 2000-2002. Resistance to seven drugs was observed in 2000-2002, whereas resistance to 21 drugs was seen during 2006-2009. The number of drug resistance pattern increased from 13 in 2000-2002 to 43 in 2006-2009. Resistance to newer generation fluoroquinolones, 3 rd generation cephalosporins and augmentin, which was not observed during 2000-2002, appeared during 2006-2009.
INTERPRETATION & CONCLUSIONS: The frequency of resistance among Shigella isolates has increased substantially between 2000-2002 and 2006-2009 and the spectrum of resistance has widened. At present, the option for antimicrobial therapy in shigellosis in Andaman is limited to a small number of drugs. Continuous local monitoring of resistance patterns is necessary for the appropriate selection of empirical antimicrobial therapy.
志贺菌病已知是印度安达曼和尼科巴群岛导致儿童急性腹泻的主要原因。抗生素耐药性的迅速出现需要持续监测细菌分离株的敏感性模式。我们在此报告印度安达曼岛正在进行的志贺菌病研究的主要发现，涉及过去十年中耐药模式的变化。
在 2006-2009 年期间，收集了 412 名儿科腹泻患者的粪便样本并进行处理，以分离和鉴定志贺菌属。对 22 种抗菌药物的敏感性进行了测试，并确定了第三代头孢菌素、喹诺酮类药物、阿莫西林-克拉维酸组合和庆大霉素的 MIC。将这些分离株的药敏模式与 2000-2002 年期间获得的 33 株分离株进行比较。
从处理的 412 份粪便样本中分离出 50 株志贺菌属。100%、96%、94%和 82%的分离株分别对氨苄西林、萘啶酸、四环素和环丙沙星耐药。这些药物的耐药率明显（P<0.001）高于 2000-2002 年观察到的耐药率。2000-2002 年观察到 7 种药物耐药，而 2006-2009 年观察到 21 种药物耐药。2000-2002 年耐药模式为 13 种，2006-2009 年耐药模式增加到 43 种。2006-2009 年出现了 2000-2002 年未观察到的新型氟喹诺酮类、第三代头孢菌素和阿莫西林-克拉维酸的耐药性。
2000-2002 年和 2006-2009 年之间志贺菌分离株的耐药率显著增加，耐药谱扩大。目前，安达曼岛志贺菌病的抗菌治疗选择有限，仅限于少数几种药物。需要持续进行当地耐药模式监测，以适当选择经验性抗菌治疗。
