Sequencing of Chlamydia pneumoniae in coronary artery disease patients attending tertiary hospital in India

Abstract

To the Editor: After perusing the report of Sharma et al1Sharma M. Fakih M.G. Berriel-Cass D. Meisner S. Saravolatz L. Khatib R. Harvest surgical site infection following coronary artery bypass grafting: risk factors, microbiology, and outcomes.Am J Infect Control. 2009; 37: 653-657Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar on surgical site infections following coronary artery bypass grafting (risk factors, microbiology, and outcomes), we thought it would be of interest to your readers to demonstrate our findings on a similar type of study in which we were interested in knowing the strains of Chlamydia pneumoniae in coronary artery disease (CAD) patients. Hence, we performed nested polymerase chain reaction (PCR) using 16S rRNA (constitutive in bacteria) gene of C pneumoniae followed by sequencing. Association of C pneumoniae with CAD has been reported globally.2Clancy R. Ren Z. Pang G. Fletcher P. Este C.D. Chronic Chlamydia pneumoniae infection may promote coronary artery disease in humans through enhancing secretion of interleukin-4.Clin Exp Immunol. 2006; 146: 197-202Crossref PubMed Scopus (6) Google Scholar, 3Higgins J.P. Chlamydia pneumoniae and coronary artery disease: The Antibiotic Trials.Mayo Clin Proc. 2003; 78: 321-332Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar, 4Wong Y-k Dawkins KD, Ward ME. Circulating Chlamydia pneumoniae DNA as a predictor of coronary artery disease.J Am Coll Cardiol. 1999; 34: 391-395Abstract Full Text Full Text PDF Scopus (104) Google Scholar To date, there are 8 strains of C pneumoniae reported worldwide; however, there is no report from India. C pneumoniae strain, which is closer to (CDC/CWL 029), was found in venous blood of CAD patients attending a tertiary hospital in New Delhi, India. Eleven CAD patients who were detected as C pneumoniae positive by 16S rRNA nested PCR were enrolled in this study after prior written consent and hospital ethical committee approval.5Jha H.C. Vardhan H. Gupta R. Varma R. Prasad J. Mittal A. Higher incidence of persistent chronic infection of Chlamydia pneumoniae among coronary artery disease patients in India is a cause of concern.BMC Infect Dis. 2007; 7: 1-8Crossref Scopus (26) Google Scholar All PCR products were purified using Qiagen Gel Extraction kit (Oiapen, GmbH, Germany) as per manufacturer's instruction. Purified product was used for DNA sequencing in Automated Sequencer (ABI PRISM 3130 XL, Foster City, CA). Resulted sequence was blast in NCBI through nonredundant blast against C pneumoniae genome database (Table 1). No significant difference was found in our C pneumoniae-positive sequences for CWL029 and those reported and available at the American Type Culture Collection. In a patient with pneumonia (throat sample), Japan has reported J138 C pneumoniae strain6Tsumura N. Chlamydia pneumoniae lower respiratory tract infections in Japanese children. Abstract: Annual Meeting 1995; ICAAC, San Francisco.Google Scholar; however, CWL029 has been reported from throat swab of pneumonia patients in the United States.7Kuo C.C. Jackson L.A. Campbell L.A. Grayston J.T. Chlamydia pneumoniae (TWAR).Clin Microbiol Rev. 1995; 8: 451-461Crossref PubMed Google Scholar There is only 1 report wherein, in coronary atheroma of a patient with atherosclerosis, C pneumoniae strain (AO3) has been detected.8Ramirez J.A. Isolation of Chlamydia pneumoniae from the coronary artery of a patient with coronary atherosclerosis. The Chlamydia Pneumoniae/Atherosclerosis Study Group.Ann Intern Med. 1996; 125: 979-982Crossref PubMed Scopus (453) Google Scholar Gieffers et al had reported that differences between respiratory and cardiovascular strains were minimal, confirming that the C pneumoniae isolates obtained so far are very homogenous in their genetic background, protein profile, and immunogenicity.9Gieffers J. Solbach W. Maass M. In vitro susceptibilities of Chlamydia pneumoniae strains recovered from atherosclerotic coronary arteries.Antimicrob Agents Chemother. 1998; 42: 2762-2764PubMed Google Scholar Because a genetic typing system has not been established for C pneumoniae, the presence of a genotype with a distinct vascular pathogenicity cannot be excluded.Table 1Chlamydia pneumoniae strains available at ATCCSpeciesStrainIdentities (similarity)Chlamydia pneumoniaeCWL029554/556AO3553/556TW-183553/556LKK-1553/556AR39553/556J138553/556IOL207553/556WBB551/556 Open table in a new tab