Differentiation of BCG-induced lymphadenitis from tuberculosis in lymph node biopsy specimens by molecular analyses of pncA and oxyR.
ABSTRACT Without culture, differentiation of bacille Calmette-Guérin-induced lymphadenitis (BCG-LA) from tuberculosis (TB) is sometimes difficult by histology, but is important because of different treatment schemes. The purpose of this study was to investigate the feasibility of differentiating BCG-LA from TB in lymph nodes (LNs) by molecular analyses of two recently identified genes, pncA and oxyR. In both genes, a single tuberculosis difference exists between Mycobacterium bovis and M. tuberculosis. M tuberculosis complex (MTC) DNA was first detected in nine of ten formalin-fixed, paraffin-embedded LNs from patients aged under 20 years with suspected mycobacterial infections, using polymerase chain reaction (PCR) for IS6110, an insertion sequence specific for MTC species. PCR, together with direct DNA sequencing and PCR-restriction fragment length polymorphism (RFLP) assay, was then performed to identify polymorphic nucleotide in pncA and oxyR, respectively. For comparison, 37 adult cases of tuberculous lymphadenitis were also analysed by PCR-single strand conformation polymorphism (SSCP) assay for pncA and by PCR-RFLP for oxyR. The results revealed that five of the nine IS6110-positive child cases had a G residue at nucleotide 169 in pncA, and also had a three-band pattern after digesting the amplified oxyR segment with AluI, suggesting BCG-LA. The remaining four child cases, as well as all adult cases with detectable IS6110, showed no motility shift in pncA PCR-SSCP and had the same one-band pattern as M. tuberculosis in oxyR PCR-RFLP, suggesting TB lymphadenitis. The data from molecular analyses showed a good correlation with the vaccination history and clinicopathological findings, except for one case. This study indicates that molecular assay of either oxyR or pncA could be a rapid and useful tool to distinguish BCG-LA from TB.
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ABSTRACT: In its role in the presentation of foreign antigens to the immune system, the lymph node is frequently involved in both local and systemic infections. This may manifest as lymphadenopathy with reactive changes or localized infectious lymphadenitis, with or without necrosis and granulomatous inflammation, depending on the infectious agent. The vast majority of these infections are routinely diagnosed using nonmolecular methods, including culture, serology, and antigen testing. However, in some cases, other methods may be unavailable, or the presentation and appearance may be atypical, and direct confirmation of the infecting agent by in situ hybridization (ISH) or amplified nucleic acid detection is desired in the lymph node tissue itself.
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ABSTRACT: Acute Q fever was previously regarded as an uncommon infectious disease in Taiwan but has been increasingly recognized recently. Acute febrile illness, hepatitis, and pneumonia are the 3 most common manifestations of this condition, whereas jaundice is rarely reported among patients with acute Q fever. We report 2 cases of acute Q fever with jaundice and multi-organ involvement. The first patient presented with fever, severe headache, and acute abdomen necessitating laparotomy and was complicated with acute cholestatic hepatitis, acute non-oliguric renal failure and disseminated intravascular coagulation. The second patient had acute cholestatic hepatitis and thrombocytopenia, and the latter was likely related to the infection of bone marrow by Coxiella burnetii, as evidenced by the presence of C. burnetii DNA detected by nested polymerase chain reaction. The incidence and clinical significance of hyperbilirubinemia was also determined by review of medical records of 35 cases of acute Q fever cases diagnosed serologically at National Cheng Kung University Hospital from 1994 to 2001. All had biochemical hepatitis and 23% had hyperbilirubinemia (serum bilirubin > or =2 mg/dL). The febrile course before admission and the period between the initiation of effective medication to defervescence were longer in patients with hyperbilirubinemia than in patients without hyperbilirubinemia, although this difference was not significant. Our results suggest that the predominant presentation of acute Q fever in southern Taiwan is acute febrile illness with hepatitis and that jaundice is not uncommon. Due to the clinical polymorphism of acute Q fever, the threshold of surveys for C. burnetii infections should be low for febrile patients with elevated transaminases or hyperbilirubinemia of unknown cause.Journal of microbiology, immunology, and infection = Wei mian yu gan ran za zhi 04/2004; 37(2):103-8. · 1.63 Impact Factor
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ABSTRACT: Molecular biology methods offer new opportunities to differentiate, identify and type bacterial species and stra-ins. These methods use the variability of nucleic sequences of genes such as 16S rDNA, beta subunit RNA-ase (rpoB), gyrase (gyrB), rDNA internal transcribed spacer and other genes. The aim of this paper is to provide comprehensive information about the methods available to differentiate and identify species of mycobacteria at the DNA sequence level. The methods discussed in the review include PCR, PCR-REA, sequencing analysis, spoligotyping and DNA fingerprinting. These methods have been applied to both the "universal" part of the genome and to specific mycobacterial genes. – gene encoding beta subunit of gyrase; IS – insertion sequence; ITS – rDNA internal transcribed spacer; INH – Isoniazid; HIV/ AIDS – Human Immune-Deficiency Virus/Acquired Immune Deficiency Syndrome; HPA – hybridisation protection assay; hsp – heat shock protein; katG – gene encoding catalase G; kDa – kilo Dalton; LCR – Ligase Chain Reaction; M. – Mycobacterium; MAC – M. avium complex; MDR–MTB – multi-drug-resistant strains of M. tuberculosis; MPTR – major polymorphic tandem repeat; MTC – M. tuberculosis complex; mtp40 – gene encoding protein of M. tuberculosis; NBT – α-naphthyl butyrate; ORF – open reading frame; oxyR – gene encoding protein of oxidative stress response; PCR – polymerase chain reaction; PCR–REA = PRA – polymerase restriction analysis; PGRS – polymorphic GC–rich repeat sequence; PE – proteins with motifs of amino acids Pro-Glu; pncA – gene encoding pyrazinamidase A; PPE – proteins with motifs of amino acid Pro-Pro-Glu; PZA – Pyrazi-namide; RNA – ribonucleic acid; rRNA – ribosomal RNA; rDNA – ribosomal DNA; RE – restriction endonuclease; REA – restriction endonuclease analysis; recA – gene encoding recombinase A; RFP – Rifampicin; RFLP – restriction fragment length polymorphism; rpoB – gene encoding beta subunit RNA-ase; SDA – strand displacement amplification; spoligotyping – spacer oligotyping; Sp. – species; Subsp. – subspecies; STM – Streptomycin; TMA – transcription mediated amplification; VNTR – variable numbers of tandem repeats.Vet. Med. – Czech. 01/2001; 46:11-12.