Characterization of Pseudomonas aeruginosa isolated from chronically infected children with cystic fibrosis in India -: art. no. 43
Characterization of Pseudomonas aeruginosa isolated from chronically infected children with cystic fibrosis in India -: art. no. 43
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DOI：
10.1186/1471-2180-5-43
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发表时间：
2005-07-21
期刊：
影响因子：
4.2
通讯作者：
Dwivedi, SN
中科院分区：
文献类型：
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作者：
Agarwal, G;Kapil, A;Dwivedi, SN
背景：铜绿假单胞菌是囊性纤维化（CF）患者发病和死亡的主要原因。随着慢性感染，细菌以生物膜的形式存在，表现出多重耐药性，菌落形态多样化，并变得营养不良。发现患者有多种基因型定植。目前的工作进行表征铜绿假单胞菌分离的儿童囊性纤维化采用表型和基因型方法。结果：我们研究了1998年8月至2001年8月在印度新德里全印度医学科学研究所儿科胸科门诊就诊的56例CF患者。这些病人定期在诊所接受随访。56例患者中，27例铜绿假单胞菌培养阳性，其中8例为慢性感染（第1组），19例为间歇性定植（第2组）。1组患者住院率、死亡率及不同菌落形态的定殖率均显著高于对照组（p < 0.05）。第1组患者的分离株是广谱β -内酰胺酶的阳性生产者。2例慢性铜绿假单胞菌感染患者和新近入组患者共恢复5个营养不良细胞。营养不良动物对蛋氨酸和精氨酸有特殊的需求。分子分型显示33种ERIC-PCR （e1 ~ e33）和5种pcr -核糖分型（p1 ~ p5）。通过ERIC-PCR， 4例患者有2-4个基因型定殖，其余23例患者为单一基因型定殖。结论：随着慢性感染，铜绿假单胞菌产生多重耐药，菌落形态多样化，获得黏液性，对氨基酸表现出营养缺陷。慢性感染患者可有多种基因型定植。因此，在特定的临床设置中，对CF患者的诊断应具有较高的怀疑指数，以免延误CF患者的诊断和管理。
Background: Pseudomonas aeruginosa is the leading cause of morbidity and mortality in patients with cystic fibrosis (CF). With chronicity of infection, the organism resides as a biofilm, shows multi-drug resistance, diversifies its colony morphology and becomes auxotrophic. The patients have been found to be colonized with multiple genotypes. The present work was carried out to characterize P. aeruginosa isolated from children with cystic fibrosis using phenotypic and genotypic methods.Results: We studied 56 patients with CF attending the Pediatric Chest clinic at All India Institute of Medical Sciences, New Delhi, India during August 1998-August 2001. These patients were regularly followed up at the clinic. Out of 56 patients, 27 were culture positive for P. aeruginosa where 8 were chronically infected (Group1) and 19 were intermittently colonized with the organism (Group2). Patients under Group1 had significantly higher rates of hospitalization, death and colonization with different colony morphotypes (p < 0.05). The isolates from Group1 patients were the positive producers of extended spectrum beta lactamase. A total of 5 auxotrophs were recovered from 2 patients where one was chronically infected with P. aeruginosa and the other was a recently enrolled patient. The auxotrophs had the specific requirement for methionine and arginine. Molecular typing revealed 33 ERIC-PCR (E1-E33) and 5 PCR-ribotyping (P1-P5) patterns. By ERIC-PCR, 4 patients were colonized with 2-4 genotypes and the remaining 23 patients were colonized with the single genotype.Conclusion: With chronicity of infection, P. aeruginosa becomes multidrug resistant, diversifies its colony morphology, acquires mucoidity and shows auxotrophy for amino acids. The chronically infected patients can be colonized with multiple genotypes. Thus in a particular clinical set up, high index of suspicion should be there for diagnosis of CF patients so as to prevent the delay in diagnosis and management of CF patients.