Hybrid & El Tor variant biotypes of Vibrio cholerae O1 in Thailand.
BACKGROUND & OBJECTIVES: El Tor Vibrio cholerae O1 carrying ctxB C trait, so-called El Tor variant that causes more severe symptoms than the prototype El Tor strain, first detected in Bangladesh was later shown to have emerged in India in 1992. Subsequently, similar V. cholerae strains were isolated in other countries in Asia and Africa. Thus, it was of interest to investigate the characteristics of V. cholerae O1 strains isolated chronologically (from 1986 to 2009) in Thailand. METHODS: A total of 330 V. cholerae O1 Thailand strains from hospitalized patients with cholera isolated during 1986 to 2009 were subjected to conventional biotyping i.e., susceptibility to polymyxin B, chicken erythrocyte agglutination (CCA) and Voges-Proskauer (VP) test. The presence of ctxA, ctxB, zot, ace, toxR, tcpA C , tcpA E, hlyA C and hlyA E were examined by PCR. Mismatch amplification mutation assay (MAMA) - and conventional- PCRs were used for differentiating ctxB and rstR alleles. RESULTS: All 330 strains carried the El Tor virulence gene signature. Among these, 266 strains were typical El Tor (resistant to 50 units of polymyxin B and positive for CCA and VP test) while 64 had mixed classical and El Tor phenotypes (hybrid biotype). Combined MAMA-PCR and the conventional biotyping methods revealed that 36 strains of 1986-1992 were either typical El Tor, hybrid, El Tor variant or unclassified biotype. The hybrid strains were present during 1986-2004. El Tor variant strains were found in 1992, the same year when the typical El Tor strains disappeared. All 294 strains of 1993-2009 carried ctxBC ; 237 were El Tor variant and 57 were hybrid. INTERPRETATION & CONCLUSIONS: In Thailand, hybrid V. cholerae O1 (mixed biotypes), was found since 1986. Circulating strains, however, are predominantly El Tor variant (El Tor biotype with ctxB C). (+info)
Respiratory viruses and atypical bacteria triggering severe asthma exacerbation in children.
1. Respiratory viruses and atypical bacteria were detected in 51.0% of Hong Kong children with asthma exacerbations, which was significantly higher than the detection rate of 27.3% in children with chronic stable asthma. 2. Co-infections of two or more respiratory pathogens were more commonly found in children with asthma exacerbations (10.7%) than in patients with stable asthma (2.6%). 3. Human rhinovirus infection was a significant risk factor for asthma exacerbations. 4. There was no significant association between the severity of asthma exacerbations and respiratory viral or atypical bacterial infections. 5. Routine use of macrolide antibiotics in the treatment of childhood asthma exacerbations should be discouraged. (+info)
Abnormal forms of Trichomonas vaginalis.
Abnormal forms of Trichomonas vaginalis have been demonstrated by both conventional and scanning electron microscopy after inoculation of media with clinical material from cases of trichomonal vaginitis. Twenty-six cases of vaginitis have been studied; 10 of them showed the abnormal forms of trichomonads after growth in a modification of the medium described by Bushby and Copp (1955), while 16 showed only normal forms. (+info)
Listeria monocytogenes endocarditis.
A fatal case of endocarditis due to Listeria monocytogenes is reported. Case reports of endocarditis due to this organism are rare but indicate a higher mortality than with many other causes of bacterial endocarditis. The size of the problem may be underestimated because the organism has a "diphtheroid' appearance and may be incorrectly dismissed as a contaminant. (+info)
Aberrant form of Pseudomonas aeruginosa in sputum and cerebrospinal fluid causing infection in a compromised patient.
A patient with non-Hodgkin's lymphoma developed meningitis due to an aberrant form of Pseudomonas aeruginosa observed on Gram stain. The organism was grown on primary isolation media without needing hypertonic media. The significance of aberrant forms in body fluids is discussed. (+info)
Acute conjunctivitis caused by an atypical chlamydial strain: Chlamydia IOL 207.
A case of acute conjunctivitis in man caused by Chlamydia IOL 207 is described. Chlamydiae were isolated from the eye, and rising titres of type-specific antibodies to C. IOL 207, in serum and tears demonstrated an aetiological role for this agent. C. IOL 207 is an atypical chlamydial strain which serological studies suggest is widespread in some communities. (+info)