Asem A Shehabi | The University Of Jordan (original) (raw)

Papers by Asem A Shehabi

Research paper thumbnail of Multifactorial modeling for caries prediction in Jordanian university students

Research paper thumbnail of Prevalence of Clostridium difficile-associated diarrhoea among hospitalized Jordanian patients

Eastern Mediterranean health journal = La revue de santé de la Méditerranée orientale = al-Majallah al-ṣiḥḥīyah li-sharq al-mutawassiṭ

We investigated stool specimens of 400 patients at Jordan University Hospital (300 patients with ... more We investigated stool specimens of 400 patients at Jordan University Hospital (300 patients with clinical diarrhoea and 100 controls without diarrhoea) for the presence of Clostridium difficile or its toxin. We found a 9.7% prevalence rate of C. difficile or its toxin in stools of patients with diarrhoea. The prevalence of other potential enteric pathogens, such as Salmonella spp. (2.3%), Shigella spp. (1.0%) and Entamoeba histolytica (2.7%), was significantly less. Prevalence of C. difficile or its toxin in controls was 3.0%. Toxin A was detected in 93.1% of C. difficile-associated diarrhoea cases using an enzyme immunoassay. Our study indicates that C. difficile-associated diarrhoea is mostly observed among hospitalized patients aged > or = 50 years, in association with antimicrobial treatment.

Research paper thumbnail of Human Metapneumovirus Infection in Jordanian Children: Epidemiology and Risk Factors for Severe Disease

The Pediatric infectious disease journal, Jan 12, 2015

Human metapneumovirus (HMPV) is a leading cause of acute respiratory tract infection (ARTI) in yo... more Human metapneumovirus (HMPV) is a leading cause of acute respiratory tract infection (ARTI) in young children. Our objectives were to define HMPV epidemiology and circulating strains and determine markers of severe disease in Jordanian children. We conducted a prospective study March 16, 2010-March 31, 2013using quantitative RT-PCR to determine the frequency of HMPV infection among children <2 years old admitted with fever and/or acute respiratory illness to a major government hospital in Amman, Jordan. HMPV was present in 273/3168 (8.6%) of children presenting with ARTI. HMPV A2, B1, and B2, but not A1, were detected during the 3-year period. HMPV-infected children were older and more likely to be diagnosed with bronchopneumonia than HMPV-negative children. HMPV-infected children with lower respiratory tract infection (LRTI) had higher rates of cough and shortness of breath than children with LRTI infected with other or no identifiable viruses. Symptoms and severity were not dif...

Research paper thumbnail of Natural history and epidemiology of respiratory syncytial virus infection in the Middle East: Hospital surveillance for children under age two in Jordan

Research paper thumbnail of iMedPub Journals Frequency of antimicrobial resistance markers among Pseudomonas aeruginosa and Escherichia coli isolates from municipal sewage effluent water and patients in

International Journal of Antimicrobial Agents

The objective of this study was to compare the frequency of antimicrobial resistance markers of P... more The objective of this study was to compare the frequency of antimicrobial resistance markers of P. aeruginosa and E.coli isolates from effluent of sewage treatment plants and clinical specimens over the same period in Jordan. A total of 212 Pseudomonas aeruginosa and 54 Escherichia coli isolates were recovered from effluent water, in ad-dition, 65 P. aeruginosa and 50 E.coli isolates were obtained from clinical specimens over the same period. High percentage of P. aeruginosa and E.coli isolates from both sources have similar multi-resistant to > 3 antimicrobial drugs, and carried common Class 1 integrons and resistance genes. The antimicrobial resistance markers; tet(B) gene, tet(A)gene, metalo-β-lactamase genes (bla OXA2 bla VIM2a , bla VIM2b) and ami-noglycoside genes (aacA) were detected in both clinical and effluent water isolates. This study indicates that strains isolated from effluent water were highly polluted with antimicrobial resistance markers similar to those observe...

Research paper thumbnail of Parainfluenza Virus Illness in Hospitalized Children in Amman, Jordan

Background: The burden of disease attributable to parainfluenza viruses in hospitalized children ... more Background: The burden of disease attributable to parainfluenza viruses in hospitalized children in Amman, Jordan is unknown. Methods: We conducted a prospective year-round viral surveillance study in children <2 years of age admitted with respiratory symptoms and/or fever at the government-run hospital, Al-Basheer. Surveillance was conducted Sunday-Thursday from 3/16/2010-1/15/12. Clinical and demographic data including antibiotic use were collected. Nasal/throat swabs were collected, placed into lysis buffer, aliquoted, and frozen at -80°C. Specimen aliquots were shipped to Vanderbilt and tested by real-time RT-PCR for respiratory syncytial virus (RSV), metapneumovirus (HMPV), rhinovirus (HRV), influenza A and B, and parainfluenza viruses 1, 2, and 3 (PIV1-3). Results: A total of 1469 subjects were enrolled. The median age was 3.5 months, with 59% male, 10% had an underlying medical condition, 1% attended day care, 76% were exposed to smokers, 8% were admitted to the ICU, and 8...

Research paper thumbnail of Review article

Research paper thumbnail of Antimicrobial resistance patterns of diarrheagenic and non-diarrheagenic Escherichia coli isolates from Libyan children

The International Arabic Journal of Antimicrobial Agents, 2014

Background: Diarrhea continues to be one of the most common cause of morbidity and mortality amon... more Background: Diarrhea continues to be one of the most common cause of morbidity and mortality among infants and children in developing countries. This study was carried out among Libyan children hospitalized in Benghazi children hospital, to be investigated for the incidence of diarrheagenic E.coli types and antimicrobial susceptibility profiles of all E.coli isolates in their stool samples.

Research paper thumbnail of THE INTERNATIONAL ARABIC JOURNAL OF ANTIMICROBIAL AGENTS © Under License of Creative Commons Attribution 3.0 License High incidence of multidrug resistant Escherichia coli producing CTX-M-type ESBLs colonizing the intestine of Jordanian infants Corresponding author

Background: This prospective study investigated major characteristics of E.coli colonizing the in... more Background: This prospective study investigated major characteristics of E.coli colonizing the intestine of out-and in-patient infants, especially their association with CTX-M-type extended spectrum β-Lactamases (ESBLs), integrons and fluoroquinolones-resistance.

Research paper thumbnail of Antimicrobial resistance and plasmid profiles of urinary Escherichia coli isolates from Jordanian patients

Eastern Mediterranean health journal = La revue de santé de la Méditerranée orientale = al-Majallah al-ṣiḥḥīyah li-sharq al-mutawassiṭ, 2004

We investigated antimicrobial resistance patterns and plasmid profiles of uropathogenic Escherich... more We investigated antimicrobial resistance patterns and plasmid profiles of uropathogenic Escherichia coli isolates from inpatients and outpatients at Jordan University Hospital in 2000 and 2001. E. coli accounted for 32.4% and 37.4% of all isolates respectively. The lowest susceptibility was for ampicillin (11%), cotrimoxazole (23%) and tetracycline (26%). The relative incidence of resistant isolates of E. coli to nalidixic acid, gentamicin, norfloxacin, cefuroxime and nitrofurantoin was significantly greater for inpatients than for outpatients (P< 0.05). A large, transferable R-plasmid of 28 kb was found in most E. coli isolates (67%) that were resistant to at least ampicillin, cotrimoxazole and tetracycline. This R-plasmid reservoir may contribute to the spread of multiple antibiotic resistance in our Region.

Research paper thumbnail of Enterotoxigenicity of clinical isolates of non-O1 Vibrio cholerae

Zentralblatt für Bakteriologie, Mikrobiologie, und Hygiene. Series A, Medical microbiology, infectious diseases, virology, parasitology, 1985

Whole cultures, but not culture supernatant fluids, of 21 isolates of non-O1 V. cholerae from pat... more Whole cultures, but not culture supernatant fluids, of 21 isolates of non-O1 V. cholerae from patients with diarrhea were shown to induce positive fluid accumulation in infant mice. CHO cell assays demonstrated the elaboration of heat-labile cytotonic, cytotoxic or both factors from most isolates when grown under optimal culture conditions. These factors were not neutralized by anti-cholera toxin serum. Also genetic studies performed on 9 vibrio isolates using a DNA hybridization probe failed to detect gene sequences homologous with cholera toxin. ELISA assays recognized six isolates which produced a cell-associated substance which immunologically cross-reacted with cholera toxin. Enzymatic profiles of the vibrio isolates did not correlate with the production of any toxic factor. The results indicate that mainly heat-labile and cell-associated cytotonic and cytotoxic factors appear to influence the enterotoxigenic potential of this heterogenous group of non-O1 vibrios.

Research paper thumbnail of Virulence mechanisms associated with clinical isolates of non-O1 Vibrio cholerae

Zentralblatt für Bakteriologie, Mikrobiologie, und Hygiene. Series A, Medical microbiology, infectious diseases, virology, parasitology, 1986

Twenty one isolates of non-O1 V. cholerae from patients with diarrheal illness were examined for ... more Twenty one isolates of non-O1 V. cholerae from patients with diarrheal illness were examined for the presence of potential virulence mechanisms. The motile strains (90%) produced cell-associated mannose-sensitive hemagglutinins which reacted with human group O, chicken, sheep and rabbit erythrocytes. Motile isolates also attached to embryonic intestinal epithelial cells (ATCC 407), and the adherence was not inhibited by the presence of 1% D-mannose. All vibrio isolates hemolyzed sheep erythrocytes. Three vibrio isolates (14%) harbored two or three plasmids which ranged in size between 1.7 and 5.2 megadaltons. The presence of the plasmid did not correlate with the presence of hemolysin, hemagglutinins, adhesions or antibiotic resistance in any of the isolates. Thus, it appears that multiple factors associated with bacterial cell surfaces influence adhesin and apparently pathogenic potential of the non-O1 vibrio isolates in the host intestine.

Research paper thumbnail of The changing epidemiology of diphtheria in Jordan

Bulletin of the World Health Organization, 1988

Outbreaks of diphtheria used to occur regularly in Jordan, the last such outbreak being in 1977-7... more Outbreaks of diphtheria used to occur regularly in Jordan, the last such outbreak being in 1977-78. Since that time, a massive immunization programme targeted at pre-school-age children has been markedly successful. Hence, when an outbreak of diphtheria occurred in 1982-83, it was unexpected. Of the 35 patients who were treated at the Jordan University Hospital, two died and the remaining 33 recovered uneventfully. Contrary to our findings in previous diphtheria epidemics in Jordan, this outbreak largely involved adolescents and young adults.

Research paper thumbnail of Rare occurrence of Mycoplasma pneumoniae infection among Jordanian adults with respiratory tract infections

Microbial Ecology in Health & Disease, 2005

A prospective study using both polymerase chain reaction (PCR) and culture demonstrated the absen... more A prospective study using both polymerase chain reaction (PCR) and culture demonstrated the absence of Mycoplasma pneumoniae in the throats of 100 Jordanian adult patients with respiratory tract infections and 100 healthy controls over a period of 8 months (2003 Á/2004). However, a retrospective study covering a period of 24 months (2003 Á/2005) indicated that M. pneumoniae serological tests were only positive in 1/15 (7.1%) of adults and 4/29 (13.8%) of children among suspected infected patients. These results suggest that M. pneumoniae infection occurs rarely in Jordanian adults and may be attributed to the prevalence of dry weather for most of the year in Jordan.

Research paper thumbnail of Indoor-Outdoor Air Leakage of Apartments and Commercial Buildings

Research paper thumbnail of Putative virulence factors of Candida species colonizing respiratory tracts of patients

Microbial Ecology in Health and Disease, 2004

The objective of this research was to investigate the patterns of Candida species colonizing resp... more The objective of this research was to investigate the patterns of Candida species colonizing respiratory tracts of hospitalized patients and their production of putative virulence factors in vitro. One hundred and twenty-nine Candida isolates were collected from respiratory tract specimens of adult Jordanian patients admitted to Jordan University Hospital (JUH) during the period 1999 Á/2001. The patterns of colonization were as follows. C. albicans accounted for (67%) of the isolates, followed by non-C. albicans isolates (33%), including C. krusei (12%), C. tropicalis (11%), C. glabrata (6%) and other Candida spp. (4%). No significant differences were determined between the Candida isolates as regards their secretion in vitro of variable amounts of putative virulence factors Á/ aspartyl proteinase, phospholipase and haemolysin (p /0.05). However, the mean production of proteinase using qualitative measurements is clearly more observed in C. albicans isolates colonizing the respiratory tract. The study concludes that putative virulence factors alone are not responsible for the colonization potential of Candida species.

Research paper thumbnail of Epidemiology and clinical outcome of candidaemia among Jordanian newborns over a 10-year period

Scandinavian Journal of Infectious Diseases, 2008

Background: There is evidence that Candida colonization contributes to increasing invasion of can... more Background: There is evidence that Candida colonization contributes to increasing invasion of candidiasis in hospitalized neonates. Few studies investigated the epidemiology and risk factors of Candida colonization among hospitalized and non-hospitalized infants. This prospective study investigated the major epidemiological characteristics of Candida species colonizing oral and rectal sites of Jordanian infants. Methods: Infants aged one year or less who were examined at the pediatrics outpatient clinic or hospitalized at the Jordan University Hospital, Amman, Jordan, were included in this study. Culture swabs were collected from oral and rectal sites and inoculated on Sabouraud dextrose agar. All Candida isolates were confirmed by the Remel RapID yeast plus system, and further investigated for specific virulence factors and antifungal susceptibility MIC using E-test. Genotyping of C. albicans isolates was determined using random amplified polymorphic DNA (RAPD) analysis method. Results: A total of 61/492 (12.4%) infants were colonized with Candida species by either their oral/rectal sites or both. Rectal colonization was significantly more detected than oral colonization (64.6% verses 35.4%), particularly among hospitalized infants aged more than one month. The pattern and rates of colonization were as follows: C. albicans was the commonest species isolated from both sites and accounted for 67.1% of all isolates, followed by C.kefyr (11.4%), each C. tropicalis and C. glabrata (8.9%) and C. parapsilosis (3.8%). A various rates of Candida isolates proved to secrete putative virulence factors in vitro; asparatyl proteinase, phospholipase and hemolysin. C. albicans were associated significantly (P < 0.05) with these enzymes than other Candida species. All Candida isolates were susceptible to amphotericin B and caspofungin, whereas 97% of Candida species isolates were susceptible to fluconazole using E-test. The genetic similarity of 53 C. albicans isolates as demonstrated by dendrogram revealed the presence of 29 genotypes, and of these one genotype accounted for 22% of the isolates.

Research paper thumbnail of Common Antimicrobial Resistance Phenotypes and Genotypes of Fecal Escherichia coli Isolates from a Single Family Over a 6-Month Period

Microbial Drug Resistance, 2009

This study investigated the antimicrobial resistance phenotypes and genotypes among fecal Escheri... more This study investigated the antimicrobial resistance phenotypes and genotypes among fecal Escherichia coli isolates from the members of a single Jordanian family over a 6-month period. A total of 55 (51%) E. coli isolates were resistant to >2, and 21 (19%) to >3 of the 14 tested antimicrobial agents, respectively. The highest resistance rates were observed to tetracycline (42%), followed by coamoxyclav and cotrimoxazole (32%), gentamicin (31%), and nalidixic acid (27%). Sixteen out of 21 (76%) multiresistant E. coli isolates (resistant to >3 drugs) transferred most of their resistance markers in vitro to E. coli K12. Five out of the six family members were colonized with E. coli carrying one or two of the two common plasmid sizes (54.3 and 13.2 kb). Ten of these isolates (48%) were positive for class 1 integron genes and harbored four tet (A) and five tet (B) genes, respectively, but all were negative for tet (39). The genetic diversity of E. coli isolates using randomly amplified polymorphic DNA-PCR demonstrated 13 major clusters of genotype groups, and most of the isolates (63%) belonged to one genotype group. This study indicates that all six family members are colonized with fecal E. coli isolates exhibiting a common number of antimicrobial resistance phenotypes and at least one prevalent genotype.

Research paper thumbnail of Multiple drug resistance and strength of attachment to surfaces in Pseudomonas aeruginosa isolates

Letters in Applied Microbiology, 2010

To investigate the presence of a relationship between the strength of attachment of Pseudomonas a... more To investigate the presence of a relationship between the strength of attachment of Pseudomonas aeruginosa to stainless steel surfaces and their observed multiple drug resistance.

Research paper thumbnail of Human metapneumovirus in hospitalized children in Amman, Jordan

Journal of Medical Virology, 2010

Human metapneumovirus (HMPV) has recently been identified as an important cause of acute respirat... more Human metapneumovirus (HMPV) has recently been identified as an important cause of acute respiratory infections (ARI) in children worldwide. However, there is little systematic data on its frequency and importance as a cause of ARI in the Middle East. We conducted a viral surveillance study in children <5 years of age admitted with respiratory symptoms and/or fever at two major tertiary care hospitals in Amman, Jordan from 1/18-3/29/07. Nose and throat swabs were collected and tested for HMPV and other respiratory viruses by real-time RT-PCR. A total of 743 subjects were enrolled. Forty-four (6%) subjects were positive for HMPV, 467 (64%) were positive for RSV and 13 (1.3%) had co-infection with both HMPV and RSV. The frequency of HMPV in January, February, and March was 4.1%, 3.0%, and 11.9% respectively. Clinical features associated with HMPV infection were similar to those of other respiratory viruses, except children with HMPV were more likely to present with fever than children not infected with HMPV. Children with HMPV and RSV co-infection were administered supplemental oxygen and were admitted to the ICU more frequently than children infected with HMPV alone or RSV alone, though these differences did not reach statistical significance. We conclude that HMPV is an important cause of acute respiratory infections in children in Amman, Jordan. Longer surveillance studies are needed to better understand the seasonal epidemiology of HMPV and to assess if co-infection with HMPV and RSV leads to more severe illness.

Research paper thumbnail of Multifactorial modeling for caries prediction in Jordanian university students

Research paper thumbnail of Prevalence of Clostridium difficile-associated diarrhoea among hospitalized Jordanian patients

Eastern Mediterranean health journal = La revue de santé de la Méditerranée orientale = al-Majallah al-ṣiḥḥīyah li-sharq al-mutawassiṭ

We investigated stool specimens of 400 patients at Jordan University Hospital (300 patients with ... more We investigated stool specimens of 400 patients at Jordan University Hospital (300 patients with clinical diarrhoea and 100 controls without diarrhoea) for the presence of Clostridium difficile or its toxin. We found a 9.7% prevalence rate of C. difficile or its toxin in stools of patients with diarrhoea. The prevalence of other potential enteric pathogens, such as Salmonella spp. (2.3%), Shigella spp. (1.0%) and Entamoeba histolytica (2.7%), was significantly less. Prevalence of C. difficile or its toxin in controls was 3.0%. Toxin A was detected in 93.1% of C. difficile-associated diarrhoea cases using an enzyme immunoassay. Our study indicates that C. difficile-associated diarrhoea is mostly observed among hospitalized patients aged &gt; or = 50 years, in association with antimicrobial treatment.

Research paper thumbnail of Human Metapneumovirus Infection in Jordanian Children: Epidemiology and Risk Factors for Severe Disease

The Pediatric infectious disease journal, Jan 12, 2015

Human metapneumovirus (HMPV) is a leading cause of acute respiratory tract infection (ARTI) in yo... more Human metapneumovirus (HMPV) is a leading cause of acute respiratory tract infection (ARTI) in young children. Our objectives were to define HMPV epidemiology and circulating strains and determine markers of severe disease in Jordanian children. We conducted a prospective study March 16, 2010-March 31, 2013using quantitative RT-PCR to determine the frequency of HMPV infection among children <2 years old admitted with fever and/or acute respiratory illness to a major government hospital in Amman, Jordan. HMPV was present in 273/3168 (8.6%) of children presenting with ARTI. HMPV A2, B1, and B2, but not A1, were detected during the 3-year period. HMPV-infected children were older and more likely to be diagnosed with bronchopneumonia than HMPV-negative children. HMPV-infected children with lower respiratory tract infection (LRTI) had higher rates of cough and shortness of breath than children with LRTI infected with other or no identifiable viruses. Symptoms and severity were not dif...

Research paper thumbnail of Natural history and epidemiology of respiratory syncytial virus infection in the Middle East: Hospital surveillance for children under age two in Jordan

Research paper thumbnail of iMedPub Journals Frequency of antimicrobial resistance markers among Pseudomonas aeruginosa and Escherichia coli isolates from municipal sewage effluent water and patients in

International Journal of Antimicrobial Agents

The objective of this study was to compare the frequency of antimicrobial resistance markers of P... more The objective of this study was to compare the frequency of antimicrobial resistance markers of P. aeruginosa and E.coli isolates from effluent of sewage treatment plants and clinical specimens over the same period in Jordan. A total of 212 Pseudomonas aeruginosa and 54 Escherichia coli isolates were recovered from effluent water, in ad-dition, 65 P. aeruginosa and 50 E.coli isolates were obtained from clinical specimens over the same period. High percentage of P. aeruginosa and E.coli isolates from both sources have similar multi-resistant to > 3 antimicrobial drugs, and carried common Class 1 integrons and resistance genes. The antimicrobial resistance markers; tet(B) gene, tet(A)gene, metalo-β-lactamase genes (bla OXA2 bla VIM2a , bla VIM2b) and ami-noglycoside genes (aacA) were detected in both clinical and effluent water isolates. This study indicates that strains isolated from effluent water were highly polluted with antimicrobial resistance markers similar to those observe...

Research paper thumbnail of Parainfluenza Virus Illness in Hospitalized Children in Amman, Jordan

Background: The burden of disease attributable to parainfluenza viruses in hospitalized children ... more Background: The burden of disease attributable to parainfluenza viruses in hospitalized children in Amman, Jordan is unknown. Methods: We conducted a prospective year-round viral surveillance study in children <2 years of age admitted with respiratory symptoms and/or fever at the government-run hospital, Al-Basheer. Surveillance was conducted Sunday-Thursday from 3/16/2010-1/15/12. Clinical and demographic data including antibiotic use were collected. Nasal/throat swabs were collected, placed into lysis buffer, aliquoted, and frozen at -80°C. Specimen aliquots were shipped to Vanderbilt and tested by real-time RT-PCR for respiratory syncytial virus (RSV), metapneumovirus (HMPV), rhinovirus (HRV), influenza A and B, and parainfluenza viruses 1, 2, and 3 (PIV1-3). Results: A total of 1469 subjects were enrolled. The median age was 3.5 months, with 59% male, 10% had an underlying medical condition, 1% attended day care, 76% were exposed to smokers, 8% were admitted to the ICU, and 8...

Research paper thumbnail of Review article

Research paper thumbnail of Antimicrobial resistance patterns of diarrheagenic and non-diarrheagenic Escherichia coli isolates from Libyan children

The International Arabic Journal of Antimicrobial Agents, 2014

Background: Diarrhea continues to be one of the most common cause of morbidity and mortality amon... more Background: Diarrhea continues to be one of the most common cause of morbidity and mortality among infants and children in developing countries. This study was carried out among Libyan children hospitalized in Benghazi children hospital, to be investigated for the incidence of diarrheagenic E.coli types and antimicrobial susceptibility profiles of all E.coli isolates in their stool samples.

Research paper thumbnail of THE INTERNATIONAL ARABIC JOURNAL OF ANTIMICROBIAL AGENTS © Under License of Creative Commons Attribution 3.0 License High incidence of multidrug resistant Escherichia coli producing CTX-M-type ESBLs colonizing the intestine of Jordanian infants Corresponding author

Background: This prospective study investigated major characteristics of E.coli colonizing the in... more Background: This prospective study investigated major characteristics of E.coli colonizing the intestine of out-and in-patient infants, especially their association with CTX-M-type extended spectrum β-Lactamases (ESBLs), integrons and fluoroquinolones-resistance.

Research paper thumbnail of Antimicrobial resistance and plasmid profiles of urinary Escherichia coli isolates from Jordanian patients

Eastern Mediterranean health journal = La revue de santé de la Méditerranée orientale = al-Majallah al-ṣiḥḥīyah li-sharq al-mutawassiṭ, 2004

We investigated antimicrobial resistance patterns and plasmid profiles of uropathogenic Escherich... more We investigated antimicrobial resistance patterns and plasmid profiles of uropathogenic Escherichia coli isolates from inpatients and outpatients at Jordan University Hospital in 2000 and 2001. E. coli accounted for 32.4% and 37.4% of all isolates respectively. The lowest susceptibility was for ampicillin (11%), cotrimoxazole (23%) and tetracycline (26%). The relative incidence of resistant isolates of E. coli to nalidixic acid, gentamicin, norfloxacin, cefuroxime and nitrofurantoin was significantly greater for inpatients than for outpatients (P< 0.05). A large, transferable R-plasmid of 28 kb was found in most E. coli isolates (67%) that were resistant to at least ampicillin, cotrimoxazole and tetracycline. This R-plasmid reservoir may contribute to the spread of multiple antibiotic resistance in our Region.

Research paper thumbnail of Enterotoxigenicity of clinical isolates of non-O1 Vibrio cholerae

Zentralblatt für Bakteriologie, Mikrobiologie, und Hygiene. Series A, Medical microbiology, infectious diseases, virology, parasitology, 1985

Whole cultures, but not culture supernatant fluids, of 21 isolates of non-O1 V. cholerae from pat... more Whole cultures, but not culture supernatant fluids, of 21 isolates of non-O1 V. cholerae from patients with diarrhea were shown to induce positive fluid accumulation in infant mice. CHO cell assays demonstrated the elaboration of heat-labile cytotonic, cytotoxic or both factors from most isolates when grown under optimal culture conditions. These factors were not neutralized by anti-cholera toxin serum. Also genetic studies performed on 9 vibrio isolates using a DNA hybridization probe failed to detect gene sequences homologous with cholera toxin. ELISA assays recognized six isolates which produced a cell-associated substance which immunologically cross-reacted with cholera toxin. Enzymatic profiles of the vibrio isolates did not correlate with the production of any toxic factor. The results indicate that mainly heat-labile and cell-associated cytotonic and cytotoxic factors appear to influence the enterotoxigenic potential of this heterogenous group of non-O1 vibrios.

Research paper thumbnail of Virulence mechanisms associated with clinical isolates of non-O1 Vibrio cholerae

Zentralblatt für Bakteriologie, Mikrobiologie, und Hygiene. Series A, Medical microbiology, infectious diseases, virology, parasitology, 1986

Twenty one isolates of non-O1 V. cholerae from patients with diarrheal illness were examined for ... more Twenty one isolates of non-O1 V. cholerae from patients with diarrheal illness were examined for the presence of potential virulence mechanisms. The motile strains (90%) produced cell-associated mannose-sensitive hemagglutinins which reacted with human group O, chicken, sheep and rabbit erythrocytes. Motile isolates also attached to embryonic intestinal epithelial cells (ATCC 407), and the adherence was not inhibited by the presence of 1% D-mannose. All vibrio isolates hemolyzed sheep erythrocytes. Three vibrio isolates (14%) harbored two or three plasmids which ranged in size between 1.7 and 5.2 megadaltons. The presence of the plasmid did not correlate with the presence of hemolysin, hemagglutinins, adhesions or antibiotic resistance in any of the isolates. Thus, it appears that multiple factors associated with bacterial cell surfaces influence adhesin and apparently pathogenic potential of the non-O1 vibrio isolates in the host intestine.

Research paper thumbnail of The changing epidemiology of diphtheria in Jordan

Bulletin of the World Health Organization, 1988

Outbreaks of diphtheria used to occur regularly in Jordan, the last such outbreak being in 1977-7... more Outbreaks of diphtheria used to occur regularly in Jordan, the last such outbreak being in 1977-78. Since that time, a massive immunization programme targeted at pre-school-age children has been markedly successful. Hence, when an outbreak of diphtheria occurred in 1982-83, it was unexpected. Of the 35 patients who were treated at the Jordan University Hospital, two died and the remaining 33 recovered uneventfully. Contrary to our findings in previous diphtheria epidemics in Jordan, this outbreak largely involved adolescents and young adults.

Research paper thumbnail of Rare occurrence of Mycoplasma pneumoniae infection among Jordanian adults with respiratory tract infections

Microbial Ecology in Health & Disease, 2005

A prospective study using both polymerase chain reaction (PCR) and culture demonstrated the absen... more A prospective study using both polymerase chain reaction (PCR) and culture demonstrated the absence of Mycoplasma pneumoniae in the throats of 100 Jordanian adult patients with respiratory tract infections and 100 healthy controls over a period of 8 months (2003 Á/2004). However, a retrospective study covering a period of 24 months (2003 Á/2005) indicated that M. pneumoniae serological tests were only positive in 1/15 (7.1%) of adults and 4/29 (13.8%) of children among suspected infected patients. These results suggest that M. pneumoniae infection occurs rarely in Jordanian adults and may be attributed to the prevalence of dry weather for most of the year in Jordan.

Research paper thumbnail of Indoor-Outdoor Air Leakage of Apartments and Commercial Buildings

Research paper thumbnail of Putative virulence factors of Candida species colonizing respiratory tracts of patients

Microbial Ecology in Health and Disease, 2004

The objective of this research was to investigate the patterns of Candida species colonizing resp... more The objective of this research was to investigate the patterns of Candida species colonizing respiratory tracts of hospitalized patients and their production of putative virulence factors in vitro. One hundred and twenty-nine Candida isolates were collected from respiratory tract specimens of adult Jordanian patients admitted to Jordan University Hospital (JUH) during the period 1999 Á/2001. The patterns of colonization were as follows. C. albicans accounted for (67%) of the isolates, followed by non-C. albicans isolates (33%), including C. krusei (12%), C. tropicalis (11%), C. glabrata (6%) and other Candida spp. (4%). No significant differences were determined between the Candida isolates as regards their secretion in vitro of variable amounts of putative virulence factors Á/ aspartyl proteinase, phospholipase and haemolysin (p /0.05). However, the mean production of proteinase using qualitative measurements is clearly more observed in C. albicans isolates colonizing the respiratory tract. The study concludes that putative virulence factors alone are not responsible for the colonization potential of Candida species.

Research paper thumbnail of Epidemiology and clinical outcome of candidaemia among Jordanian newborns over a 10-year period

Scandinavian Journal of Infectious Diseases, 2008

Background: There is evidence that Candida colonization contributes to increasing invasion of can... more Background: There is evidence that Candida colonization contributes to increasing invasion of candidiasis in hospitalized neonates. Few studies investigated the epidemiology and risk factors of Candida colonization among hospitalized and non-hospitalized infants. This prospective study investigated the major epidemiological characteristics of Candida species colonizing oral and rectal sites of Jordanian infants. Methods: Infants aged one year or less who were examined at the pediatrics outpatient clinic or hospitalized at the Jordan University Hospital, Amman, Jordan, were included in this study. Culture swabs were collected from oral and rectal sites and inoculated on Sabouraud dextrose agar. All Candida isolates were confirmed by the Remel RapID yeast plus system, and further investigated for specific virulence factors and antifungal susceptibility MIC using E-test. Genotyping of C. albicans isolates was determined using random amplified polymorphic DNA (RAPD) analysis method. Results: A total of 61/492 (12.4%) infants were colonized with Candida species by either their oral/rectal sites or both. Rectal colonization was significantly more detected than oral colonization (64.6% verses 35.4%), particularly among hospitalized infants aged more than one month. The pattern and rates of colonization were as follows: C. albicans was the commonest species isolated from both sites and accounted for 67.1% of all isolates, followed by C.kefyr (11.4%), each C. tropicalis and C. glabrata (8.9%) and C. parapsilosis (3.8%). A various rates of Candida isolates proved to secrete putative virulence factors in vitro; asparatyl proteinase, phospholipase and hemolysin. C. albicans were associated significantly (P < 0.05) with these enzymes than other Candida species. All Candida isolates were susceptible to amphotericin B and caspofungin, whereas 97% of Candida species isolates were susceptible to fluconazole using E-test. The genetic similarity of 53 C. albicans isolates as demonstrated by dendrogram revealed the presence of 29 genotypes, and of these one genotype accounted for 22% of the isolates.

Research paper thumbnail of Common Antimicrobial Resistance Phenotypes and Genotypes of Fecal Escherichia coli Isolates from a Single Family Over a 6-Month Period

Microbial Drug Resistance, 2009

This study investigated the antimicrobial resistance phenotypes and genotypes among fecal Escheri... more This study investigated the antimicrobial resistance phenotypes and genotypes among fecal Escherichia coli isolates from the members of a single Jordanian family over a 6-month period. A total of 55 (51%) E. coli isolates were resistant to >2, and 21 (19%) to >3 of the 14 tested antimicrobial agents, respectively. The highest resistance rates were observed to tetracycline (42%), followed by coamoxyclav and cotrimoxazole (32%), gentamicin (31%), and nalidixic acid (27%). Sixteen out of 21 (76%) multiresistant E. coli isolates (resistant to >3 drugs) transferred most of their resistance markers in vitro to E. coli K12. Five out of the six family members were colonized with E. coli carrying one or two of the two common plasmid sizes (54.3 and 13.2 kb). Ten of these isolates (48%) were positive for class 1 integron genes and harbored four tet (A) and five tet (B) genes, respectively, but all were negative for tet (39). The genetic diversity of E. coli isolates using randomly amplified polymorphic DNA-PCR demonstrated 13 major clusters of genotype groups, and most of the isolates (63%) belonged to one genotype group. This study indicates that all six family members are colonized with fecal E. coli isolates exhibiting a common number of antimicrobial resistance phenotypes and at least one prevalent genotype.

Research paper thumbnail of Multiple drug resistance and strength of attachment to surfaces in Pseudomonas aeruginosa isolates

Letters in Applied Microbiology, 2010

To investigate the presence of a relationship between the strength of attachment of Pseudomonas a... more To investigate the presence of a relationship between the strength of attachment of Pseudomonas aeruginosa to stainless steel surfaces and their observed multiple drug resistance.

Research paper thumbnail of Human metapneumovirus in hospitalized children in Amman, Jordan

Journal of Medical Virology, 2010

Human metapneumovirus (HMPV) has recently been identified as an important cause of acute respirat... more Human metapneumovirus (HMPV) has recently been identified as an important cause of acute respiratory infections (ARI) in children worldwide. However, there is little systematic data on its frequency and importance as a cause of ARI in the Middle East. We conducted a viral surveillance study in children <5 years of age admitted with respiratory symptoms and/or fever at two major tertiary care hospitals in Amman, Jordan from 1/18-3/29/07. Nose and throat swabs were collected and tested for HMPV and other respiratory viruses by real-time RT-PCR. A total of 743 subjects were enrolled. Forty-four (6%) subjects were positive for HMPV, 467 (64%) were positive for RSV and 13 (1.3%) had co-infection with both HMPV and RSV. The frequency of HMPV in January, February, and March was 4.1%, 3.0%, and 11.9% respectively. Clinical features associated with HMPV infection were similar to those of other respiratory viruses, except children with HMPV were more likely to present with fever than children not infected with HMPV. Children with HMPV and RSV co-infection were administered supplemental oxygen and were admitted to the ICU more frequently than children infected with HMPV alone or RSV alone, though these differences did not reach statistical significance. We conclude that HMPV is an important cause of acute respiratory infections in children in Amman, Jordan. Longer surveillance studies are needed to better understand the seasonal epidemiology of HMPV and to assess if co-infection with HMPV and RSV leads to more severe illness.