[Detection of Salmonella, Listeria and resistant bacteria to third generation cephalosporins in the Akkawi cheese in Northern Lebanon]

The detection and limitation of microorganisms that cause disease are important parts of food microbiology. Cheese and dairy products can serve as vehicles for transmission of infectious diseases. This study aims firstly to examine the presence of two important bacteria in food microbiology, Salmonella spp and Listeria monocytogenes by the immunological technique mini-VIDAS and secondly to isolate the multi drug-resistant bacteria using a medium supplemented by a third-generation cephalosporin. Fifty samples of Akkawi cheese randomly selected from the region of north Lebanon were tested. The screening for Listeria monocytogenes and Salmonella spp by the mini-VIDAS technique gave five positive results for Listeria monocytogenes and two positive results for Salmonella spp. The confirmation by biochemical identification showed that among the 5 mini-VIDAS positive results for Listeria monocytogenes, one isolate was identified as Listeria grayi, one as Aerococcus viridans, one as Streptococcus uberis, one as Brevibacterium spp and one as CDC group 1. The two positive mini-VIDAS Salmonella spp were identified as Salmonella group 1 and Enterobacter cloacae. The search for bacteria resistant to antibiotics has shown that out of the 50 samples analyzed, 21 samples contained Gram negative bacilli resistant to beta-lactam antibiotics [42%]. Results showed the presence of 11 isolates belonging to the family of Enterobacteriaceae and 15 non-enteric bacteria isolates. The antibiotic susceptibility profiles have demonstrated that in the group of Enterobacteriaceae, six isolates were ESBL [extended spectrum beta-lactamase] producers [3 E. coli, 2 Klebsiella pneumoniae and 1 Rhanella aquatilis] and 3 were cephalosporinase hyper-producing isolates [Enterobacter cloacae, Serratia odorifera and Hafnia alvei]. Regarding the non-enteric bacteria, one notes the presence of 8 strains of Acinetobacter calcoaticus, 3 Burkholderia cepacia, 2 Pseudomonas aeruginosa, 1 Sphingomonas paucimobilis and 1 Stenotrophomonas maltophiliae. Results on the presence of bacteria resistant to antibiotics in the analyzed cheese samples indicate a real problem for public health and should draw attention to the need to implement adequate control systems in this country.

Genotypic detection of rifampicin-resistant M.tuberculosis strains in Syrian and Lebanese patients

The incidence of multi- and extensively drug-resistant TB cases is increasing in many countries. Resistance to rifampicin is widely considered a surrogate marker for multiple drug resistant TB. No efforts have been made to identify and quantify the drug-resistant genotypes in the Syrian and Lebanese communities. The genotypic characterization of rpo B mutations in the rifampicin drug-resistance region [RRDR] of resistant Mycobacterium tuberculosis isolates in Syrian and Lebanese patients. The pyrosequencing technique was applied to DNA derived from the M. tuberculosis isolates of 56 patients. RRDR sequencing identified 97 modified codons representing 35 different mutations; 31 [34%] of the 97 modifications were novel and have not been previously reported. The changes were mostly within codons 531 [37/97: 38%], 533 [28/97: 29%] and 526 [9/97: 9%]. Additionally, 30 [54%] isolates had multiple codon changes. This study indicates the importance of the RRDR hotspot region for the detection of rifampicin resistance in MTB clinical isolates from Syrian and Lebanese patients. However, new mutations and mutations in other locations within the RRDR were also observed. The vast majority [95%] of the studied isolates from this pool of patients contained mutations in codons 531 and/or 533

First description of gastroenteritis viruses in Lebanese children: a pilot study

Human enteric viruses are important causes of acute gastroenteritis in infants and children. The role of rotaviruses, adenoviruses, human caliciviruses and astroviruses in the development of severe acute gastroenteritis requiring hospitalization of infants and young children in North Lebanon was investigated. Stool specimens collected between April and May 2010 from 79 Lebanese infants and children hospitalized for severe acute gastroenteritis, were screened for enteric viruses by immunoassays and internally controlled multiplex PCR assay. Out of 79 stool samples, 38 [48%] were positive for rotavirus, and 5 [6%] were positive for norovirus genogroup II. Enteric adenoviruses, sapoviruses and human astroviruses were not detected. Children with severe rotavirus gastroenteritis were younger than those with severe norovirus gastroenteritis. These results highlight the importance of rotavirus and norovirus as causes of severe gastroenteritis in Lebanese children, and the need to incorporate routine screening tests for norovirus infection in clinical settings

[Preliminary study on prevalence of Legionella pneumophila infections in Lebanon]

After the first outbreak of Legionnaire disease was described for the first time in 1976, legionellosis has been increasingly recognized in association with many outbreaks, both community and hospital acquired. This disease remains a model of water borne transmission. In Lebanon, no report has yet been published on the prevalence of Legionella pneumophila infections. This study aims to evaluate the prevalence of legionellosis in hospitalized patients with community acquired pneumonia [CAP] and in patients with nosocomial pneumonia [HAP]. The study was conducted between April 2004 and August 2007. Eleven community hospitals participated to this endeavour. Laboratory evaluation was conducted in two centers [Middle East Health Institute, Bsalim, Lebanon and Nini Hospital, Tripoli, Lebanon]. Two hundred and forty two urinary samples and ninety one pulmonary samples from 242 patients were analyzed. The age range was 16 to 71 years. Two hundred and fifteen were from community acquired pneumonias and twenty seven were nosocomially acquired in intensive care units. The urinary antigen was investigated in 242 patients; the Binax kit" was used in this research. In lung secretions of 91 patients, the presence of Legionella pneumophila was searched for using direct immunofluorescence method and culture. Among the 215 urinary samples from patients with CAP, three were positive for Legionella antigen with a prevalence of 1.4%. Among the 27 patients with HAP, one was positive for Legionella antigen with a prevalence of 3.7%. This preliminary study reveals the fact that legionellosis is indeed present in Lebanon, hence the importance of considering it in the work-up and the management of patients with pneumonia. Hospital laboratories should therefore routinely search for this pathogen through at least urinary antigen detection. Health authorities should also enforce microbiological regulations concerning water sanitation in hospitals and in the community to prevent the establishment of this pathogen and prevent outbreaks such as those witnessed recently in many countries

[From Pseudomonas taxonomy Genre: Retrospective and news]

Bacteria of the genus Pseudomonas belong to the family Pseudomonadaceae. They are ubiquitous and have a particular interest in medical, food, water and environmental microbiology and agronomy. Some species are potentially usable in the field of agriculture and for the sanitation of ecosystems polluted with xenobiotic compounds. The masterly work of Palleroni, based on ribosomal ribonucleic acid [rRNA] homology, has shown the depth heterogeneity in the genus Pseudomonas and resulted the reshuffle of this genus in 5 groups of rRNA homology. This restructuration was thereafter confirmed by recent investigations including numerical analysis of phenotypic characters, ubiquinone study, determination of the pattern of cellular fatty acids 3-hydroxy and 16S rRNA sequencing. Species taken as Pseudomonas [groups II to V of Palleroni] were assigned to preexisting genera or to new genera. Pseudomonas <> are authentic Pseudomonas and correspond to group 1 of Palleroni. The genus gathers about sixty species that are isolated from various ecosystems. These species may or may not produce fluorescent pigments called pyoverdines and can be distinguished from related genera by the presence of ubiquinone 9 and the specific cellular fatty acids 3-hydroxy [3-hydroxydecanoic [3-OH 10:0] and 3-hydroxydodecanoic [3-OH 12:0] acids] and are unable to accumulate the poly-beta-hydroxybutyrate

Recherche des bacilles acido-alcoolo-resistants dans 1222 prelevements pathologiques

Between October 1991 and december 1995, 1222 biological specimens [sputum, pus, urine, biological liquids and biopsies] were examined for the presence of acid-fast bacilli [AFB]. After treatment in the laboratory, the smears were colored by ziehl-neelson method. 138 specimens were considered positive [11.29%]. The results showed that the rate of infection is more important in men [7.53%] than in women [3.76%]. The sputum is major in this study [84.45%], followed by biological liquids [7.61%]. The percentage of positivity was more important in the case of pus[19.44%], followed by sputum [12.30%]