Fuad Hashwa

Identification of Bacillus kaustophilus, Bacillus thermocatenulatus and Bacillus strain HSR as members of Bacillus thermoleovorans

Summary An aerobic, endospore forming thermophilic microorganism was isolated from a soil sample in Jordan. The cells stained Gram-positive and the cylindrical spores are terminal and wider than the mother cell. Growth occurs at temperature values between 45 °C and 70 °C, with an optimum at 55°C. The optimum pH for growth is 7.0. The G + C content of the DNA is 50.4 mol% and the sequence analysis of the 16S rDNA shows that the new isolate is phylogenetically closely related to the members of the Bacillus rRNA Group 5. DNA-DNA hybridization studies revealed a high similarity between the new isolate and the thermophilic species of the above mentioned group. A number of thermophilic Bacillus species are combined on the basis of DNA-DNA hybridization data.

Properties of extremely thermostable proteases from anaerobic hyperthermophilic bacteria

SummaryHyperthermostable proteases were characterized from five archaeobacterial species (Thermococcus celer, T. stetteri, Thermococcus strain AN 1, T. litoralis, Staphylothermus marinus) and the hyperthermophilic eubacterium Thermobacteroides proteolyticus. These proteases, which were found to be of the serine type, exhibited a preference for phenylalanine in the carboxylic side of the peptide. The enzymes from Thermococcus stetteri and T. litoralis hydrolysed most substrates (peptides) tested. All proteases were extremely thermostable and demonstrated optimal activities between 80 and 95°C. The pH optimum was either neutral (T. celer, Thermococcus strain AN 1) or alkaline. The protease of Thermobacteroides proteolyticus was optimally active at pH 9.5. Zymogram staining showed the presence of multiple protease bands for all strains investigated.

Geographical Structure of the Y-chromosomal Genetic Landscape of the Levant: A coastal-inland contrast

We have examined the male‐specific phylogeography of the Levant and its surroundings by analyzing Y‐chromosomal haplogroup distributions using 5874 samples (885 new) from 23 countries. The diversity within some of these haplogroups was also examined. The Levantine populations showed clustering in SNP and STR analyses when considered against a broad Middle‐East and North African background. However, we also found a coastal‐inland, east‐west pattern of diversity and frequency distribution in several haplogroups within the small region of the Levant. Since estimates of effective population size are similar in the two regions, this strong pattern is likely to have arisen mainly from differential migrations, with different lineages introduced from the east and west.

Geographical Structure of the Y-chromosomal Genetic Landscape of the Levant

We have examined the male‐specific phylogeography of the Levant and its surroundings by analyzing Y‐chromosomal haplogroup distributions using 5874 samples (885 new) from 23 countries. The diversity within some of these haplogroups was also examined. The Levantine populations showed clustering in SNP and STR analyses when considered against a broad Middle‐East and North African background. However, we also found a coastal‐inland, east‐west pattern of diversity and frequency distribution in several haplogroups within the small region of the Levant. Since estimates of effective population size are similar in the two regions, this strong pattern is likely to have arisen mainly from differential migrations, with different lineages introduced from the east and west.

Antibiotic resistance patterns and sequencing of class I integron from uropathogenic Escherichia coli in Lebanon

Aim:  To study the prevalence and molecular basis of antimicrobial resistance in UPEC.

Methicillin-resistant Staphylococcus aureus ST80-IV clone in children from Jordan

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of infections that are becoming increasingly difficult to combat because of emerging resistance. In this study, 103 S. aureus, 41 MRSA and 62 methicillin-sensitive Staphylococcus aureus isolates, were collected from children in Jordan. Genotyping based on spa and multilocus sequence typing (MLST) revealed 48 different spa types and identified distinct allelic profiles or STs, with the majority belonging to ST80. Pulsed-field gel electrophoresis (PFGE) of 15 different spa types revealed 8 different PFGE types, while SCCmec showed the predominance (53%) of subtype IV. Clustering SCCmec along with MLST revealed that ST80-MRSA-IV was the dominant type. Results obtained suggest that a significant amount of clonal spread is occurring in Jordan. The mechanism of spread of the ST80-IV clone is not known, and control measures are needed to reduce further spread of this or of other clones among children in Jordan.

emm typing, antibiotic resistance and PFGE analysis of Streptococcus pyogenes in Lebanon

One hundred and three Streptococcus pyogenes isolates recovered mainly from streptococcal throat infections in Lebanon were characterized by emm and PFGE typing. Thirty-three emm types and subtypes were detected among the isolates. PFGE was more discriminatory as a typing method. The prevalent emm types were emm1 (12.6 %), emm22 (8.7 %), emm28 (7.7 %), emm88 (7.7 %) and emm4 (6.8 %) and all isolates were susceptible to vancomycin and penicillin G. Ten per cent of the isolates were resistant to erythromycin and 3 % were resistant to erythromycin and clindamycin, showing the macrolide-lincosamide-streptogramin B phenotype. The emm sequences and PFGE pattern database that were generated in this study will serve as a basis for information for long-term evolutionary and epidemiological studies of local S. pyogenes recovered not only in Lebanon, but also in neighbouring countries.

Toxins and Antibiotic Resistance in Staphylococcus aureus Isolated from a Major Hospital in Lebanon

Molecular characterization of Staphylococcus aureus is of both clinical and infection control importance. Virulence determinants using PCR and multiple drug resistance profiles were studied in 130 S. aureus isolates. PCR-RFLP analysis of the 16S–23S DNA spacer region was done to investigate the level of 16S–23S ITS (internal transcribed spacer) polymorphism. Methicillin-resistant S. aureus (MRSA), which represented 72% of the studied isolates, showed multiple drug resistance with 18% being resistant to 10–18 of the drugs used compared to a maximum resistance to 9 antibiotics with the methicillin sensitive S. aureus (MSSA) isolates. Exfoliative toxin A (ETA) was more prevalent than B (ETB) with virulent determinants being additionally detected in multiple drug-resistant isolates. 16S–23S ITS PCR-RFLP combined with sequencing of the primary product was successful in generating molecular fingerprints of S. aureus and could be used for preliminary typing. This is the first study to demonstrate the incidence of virulent genes, ACME, and genetic diversity of S. aureus isolates in Lebanon. The data presented here epitomize a starting point defining the major genetic populations of both MRSA and MSSA in Lebanon and provide a basis for clinical epidemiological studies.

Thermostable amylase from an aerobic, gram-negative, non-spore forming thermophilic bacterium.

SummaryAn obligate aerobic, rod-shaped, Gram-negative, non-spore forming thermophilic bacterium was isolated from soil (Jordan) on starch nutrient agar at 60°C. Starch, dextrin, maltose and pullalan induced the synthesis of amylase, while glucose, lactose and fructose did not. The formation of heat stable amylase started in the early exponential phase, while maximal extracellular enzyme activity (21.75 U/ml) was detected at the end of the decline phase when most of the cells appeared as spheres.

Incidence of Antibiotic Resistance in Coliforms from Drinking Water and Their Identification Using the Biolog and the API Identification Systems

Abstract Antibiotic-resistant bacteria were common in samples collected from an intermittent water distribution system in Lebanon. Multiply-resistant isolates were also present and most commonly to amoxycillin, cephalexin and sulfamethoxazole/trimethoprim. The aminoglycosides (amikacin, gentamicin and kanamycin) were the most effective, with almost all tested strains showing susceptibility to these antimicrobial agents. Both the Biolog GN MicroPlates and the API 20E strips can be used for the identification of coliform bacteria isolated from potable water, but the outcome of the identification should be viewed with caution. 51% of isolates were assigned similar identities by both the Biolog MicroPlates and the API 20E strips. The similarity at the species level was lower (33%) compared to that at the genus level (67%). The identification of Escherichia coli strains, which represented 30% of all tested organisms, showed 95% similarity in the assigned genus and species using both identification schemes.