Pyrosequencing for rapid detection of tuberculosis resistance to Rifampicin and Isoniazid in Syrian and Lebanese clinical isolates

Rapid and accurate techniques are always welcomed for the detection of resistant strains of Mycobacterium tuberculosis MTB. The objective of this study is to evaluate the pyrosequencing technology for the detection of MTB resistance to Rifampicin [RIF] and Isoniazid [INH] in Syrian and Lebanese clinical strains; 66 strains resistant to INH, among them 56 resistant also to RIF, were tested. Four pyrosequencing assays were optimized and applied to the following loci: rpoBrpoB RIF resistance-determining region, katG, the promoter regions of inhA and ahpC-oxyR intergenic region. The prevalence of mutations on codon 315 of the katG gene, inhA and ahpc-oxyR were 42.4%, 21.2% and 9.0%, respectively, which make an overall sensitivity of 72.6% for INH resistance. All RIF-resistant strains contained at least one non-synonymous codon change in the sequenced rpoB region [507-533] relative to the ATCC reference strain. The RIF drug resistance region [RRDR] sequencing identified 96 modified codons representing 34 different mutations. The high sensitivity and the short turnaround time combined with multilocus sequencing of several isolates in parallel make pyrosequencing an attractive method for drug resistance screening for MTB

Mycobacterium tuberculosis spoligotypes circulating in the Lebanese population: a retrospective study

Genotyping Mycobacterium tuberculosis in Lebanon on the national level may be beneficial for assessing patients and monitoring the therapeutic response to DOTS. This study aimed to characterize the spoligotypes of clinical isolates of M tuberculosis patients collected between April 2004 and October 2005 from all Lebanese provinces. Isolates [n = 60] were cultured and identified by their biochemical characteristics. DNA extracts of these samples were amplified by PCR and genotyped by spoligotyping. Thirteen [13] patterns of M tuberculosis complex family strains were identified: 41.6% of the strains belonged to the T 1 family, 25.0% to LAM 9,10.0% to Haarlem 3, 3.3% to each of CAS, LAM 8, BCG and Family 36 and17% to each of Haarlem 1, LAM 10, S, M. africanum, X 1 and T 3 families. The noticeable absence of Beijing and East African Indian families was not,consistent with the patterns reported in neighbouring countries. A more inclusive study of the Lebanese population Is necessary to accurately identify most of the prevailing families in the country

Preliminary study on the prevalence of Campylobacter in childhood diarrhoea in north Lebanon

Campylobacter species are a major cause of human diarrhoeal disease worldwide. In Lebanon, the true prevalence of Campylobacter infections and the species distribution in childhood diarrhoea are not known. This study in 2010 investigated the prevalence of Campylobacter species and its possible etiologic role in childhood diarrhoea in north Lebanon. A total of 90 stool samples from children [aged 1 month to 10 years] presenting with diarrhoea were collected from 5 hospitals. A polymerase chain reaction technique [PCR] was used for each sample for the amplification of all Campylobacter species followed by 5 PCR reactions for the amplification of C. jejuni, C. hyointestinalis, C. coli, C. fetusand C. upsaliensis. Of the 90 samples, 10 were positive for Campylobacter species [11.1%]: 1 for C .coli, 1 for C. jejuni, 2 for both C. jejuni and C. coli, and 6 could not be identified to the species level with the available primers. Campylobacter species is frequently associated with childhood diarrhoea in north Lebanon but Campylobacter infection may be significantly underdiagnosed because the search for Campylobacteria not part of the routine stool culture

[Prevalence of infection by intestinal parasites in north Lebanon: 1997-2001]

We determined the prevalence of intestinal parasites in the north of Lebanon between 1997 and 2001. We analysed the parasitology records of 17126 patients and evidence of parasitic infections was found in 5 713 [33.35%] cases. There was no significant difference in prevalence for males or females for any of the parasites. The most prevalent parasites were Entamoeba coli [38.45%], Ascaris lumbricoides [37.14%], Giardia lamblia [15.39%], Ent. histolytica [4.57%] and Taenia sp. [3.3%]. A comparison between our data and results of previous studies in Lebanon in 1937, 1939, 1956, 1967 and 1993 showed an increase in the prevalence of A. lumbricoides and G. lamblia in the period 1997-2001, with less marked changes in the prevalence of the other parasites