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Naiel Bisharat

Publications and source records attributed to Naiel Bisharat.

11 recordsLinked to original sources
PubMed2006

Enhanced invasiveness of bovine-derived neonatal sequence type 17 group B streptococcus is independent of capsular serotype.

BACKGROUND: A defined geographical area (Oxford, United Kingdom) was investigated for the role of group B Streptococcus (GBS) as a human pathogen. METHODS: GBS carriage in pregnant women and invasive disease in neonates and adults >60 years of age was studied over a 3-year period. Multilocus sequence typing and capsular serotyping were used to study 369 isolates of GBS from carriage in pregnant women (n=190) and invasive disease in neonates (n=109) and adults >60 years of age (n=70). RESULTS: A total of 20.3% of pregnant women carried GBS. Invasive GBS disease occurred at a rate of 0.9 cases per 1000 live births and 11 cases per 100,000 population >60 years of age per annum. Four sequence types (STs) (ST-17, ST-19, ST-23, and ST-1) that were identified with use of multilocus sequence typing accounted for >50% of carried and invasive strains. A single sequence type (ST-17), previously shown to be phylogenetically of bovine origin, was significantly associated with increased invasiveness in neonates (P=.00002), and this was independent of capsular serotype III. In contrast, among adults >60 years of age, no STs exhibited increased invasiveness, compared with STs carried in pregnant women. CONCLUSIONS: Enhanced invasiveness associated with ST-17 is specific to neonates and is independent of capsular serotype.

Adult↗
PubMed2006

Eosinophilic pancreatic infiltration as a manifestation of lung carcinoma.

A 68-year-old man reported upper abdominal pain during the previous 3 months that worsened in the last 2 days. He had a history of lung squamous cell carcinoma for which he underwent right lung lobectomy 3 years earlier. Preliminary blood tests showed leucocytosis with marked eosinophilia. No evidence of recurrent malignancy was detected, but computed tomography scan of the abdomen revealed an enlarged and edematous pancreas with hyperemia and infiltration of the peripancreatic fat. Fine needle aspiration from the lesion revealed inflammatory infiltration predominantly composed of eosinophils. The diagnosis of eosinophilic pancreatitis was suggested and the patient was placed on prednisone, but without any clinical or laboratory improvement. Two months later, the patient developed severe dyspnea, chylothorax, and acute renal failure. Cytologic studies of the pleural fluid revealed malignant cells from recurrent lung squamous cell carcinoma. The disease course was characterized by rapid deterioration and a fatal outcome. To the authors' knowledge, eosinophilic pancreatic infiltration as a manifestation of lung carcinoma has not been previously reported.

Aged↗
PubMed2005

Population structure of group B streptococcus from a low-incidence region for invasive neonatal disease.

The population structure of group B streptococcus (GBS) from a low-incidence region for invasive neonatal disease (Israel) was investigated using multilocus genotype data. The strain collection consisted of isolates from maternal carriage (n=104) and invasive neonatal disease (n=50), resolving into 46 sequence types. The most prevalent sequence types were ST-1 (17.5 %), ST-19 (10.4 %), ST-17 (9.7 %), ST-22 (8.4 %) and ST-23 (6.5 %). Serotype III was the most common, accounting for 29.2 % of the isolates. None of the serotypes was significantly associated with invasive neonatal disease. burst analysis resolved the 46 sequence types into seven lineages (clonal complexes), from which only lineage ST-17, expressing serotype III only, was significantly associated with invasive neonatal disease. Lineage ST-22 expressed mainly serotype II, and was significantly associated with carriage. The distribution of the various sequence types and lineages, and the association of lineage ST-17 with invasive disease, are consistent with the results of analyses from a global GBS isolate collection. These findings could imply that the global variation in disease incidence is independent of the circulating GBS populations, and may be more affected by other risk factors for invasive GBS disease, or by different prevention strategies.

Carrier State↗
PubMed2005

Hybrid Vibrio vulnificus.

The recent emergence of the human-pathogenic Vibrio vulnificus in Israel was investigated by using multilocus genotype data and modern molecular evolutionary analysis tools. We show that this pathogen is a hybrid organism that evolved by the hybridization of the genomes from 2 distinct and independent populations. These findings provide clear evidence of how hybridization between 2 existing and nonpathogenic forms has apparently led to the emergence of an epidemic infectious disease caused by this pathogenic variant. This novel observation shows yet another way in which epidemic organisms arise.

Animals↗
PubMed2004

Multilocus sequence typing of serotype III group B streptococcus and correlation with pathogenic potential.

Serotype III group B streptococcus (GBS) causes more invasive disease in infants than do other serotypes in North America. We used multilocus sequence typing to identify clones within 28 invasive serotype III GBS isolates identified from a population-based study and 55 serotype III GBS colonizing isolates from a cohort of women from the same population. Ten allelic sequence types (STs) were identified and primarily involved 2 profiles: ST-19 (57.1% of invasive isolates and 58.2% of colonizing isolates) and ST-17 (32.1% of invasive isolates and 29.1% of colonizing isolates). On concatenation, the 10 allelic profiles converged into 3 groups. Group 1 consisted of ST-19 complex, ST-36, and ST-1, and was closely related to reference genome 2603V/R (serotype V). Group 2 consisted of ST-17 complex. Group 3 consisted of ST-23 complex and was closely related to the serotype III genome strain NEM 316. Neither of the major sequence types or groups was more commonly associated with invasion (P=.61) or with lower levels of maternal capsular polysaccharide-specific IgG (0.89 microg/mL and 0.39 microg/mL, respectively) for ST-19 and ST-17 (P=.86). The close association of genomic strain 2603V/R (serotype V) with ST-19 suggests that the phenomenon of capsule switching may have occurred.

Alleles↗
PubMed2004

Hyperinvasive neonatal group B streptococcus has arisen from a bovine ancestor.

The genetic relatedness and evolutionary relationships between group B streptococcus (GBS) isolates from humans and those from bovines were investigated by phylogenetic analysis of multilocus sequence typing data. The collection of isolates consisted of 111 GBS isolates from cows with mastitis and a diverse global collection of GBS isolates from patients with invasive disease (n = 83) and carriers (n = 69). Cluster analysis showed that the majority of the bovine isolates (93%) grouped into one phylogenetic cluster. The human isolates showed greater diversity and clustered separately from the bovine population. However, the homogeneous human sequence type 17 (ST-17) complex, known to be significantly associated with invasive neonatal disease, was the only human lineage found to be clustered within the bovine population and was distinct from all the other human lineages. Split decomposition analysis revealed that the human isolate ST-17 complex, the major hyperinvasive neonatal clone, has recently arisen from a bovine lineage.

Animals↗
PubMed2004

Identification of the emerging pathogen Vibrio vulnificus biotype 3 by commercially available phenotypic methods.

Identification of the emerging pathogen Vibrio vulnificus biotype 3 has become a challenge for clinical laboratories in the last few years. In this study, the abilities of five commercial systems to identify this new species have been evaluated for the first time, using a unique collection of strains. Fifty-one well-documented wild strains of V. vulnificus biotype 3 were processed using API 20 NE, GNI+ Vitek 1 cards, ID-GNB Vitek 2 cards, Neg Combo 20 Microscan panels, and NMIC/ID-5 BD Phoenix panels. The numbers of strains identified as V. vulnificus by ID-GNB, NMIC/ID-5, and GNI+ were 50 (98.0%), 46 (90.2%), and 7 (13.7%), respectively. Neg Combo 20 Microscan panels and API 20 NE were unable to identify any of the strains of this emerging pathogen to the species level and mostly misidentifies them as other species of the Vibrionaceae family. Data on the phenotypic pattern of V. vulnificus biotype 3 when processed in all five systems as presented here could help clinical laboratories in identifying this new pathogen.

Automation↗
PubMed2004

Serotype III Streptococcus agalactiae from bovine milk and human neonatal infections.

Streptococcus agalactiae (group B streptococcus [GBS]) causes invasive human infections and bovine mastitis. This study examined the genetic relationship between bovine and human serotype III GBS by using molecular techniques that classify human serotype III GBS into four distinct phylogenetic lineages. Bovine serotype III GBS were largely contained in two lineages, which are distinct from the two major lineages (restriction digest types III-2 and III-3) that infect human neonates. One of the bovine lineages closely resembles the human III-1 lineage, whose members occasionally cause human neonatal infections. The bovine strains in the other lineage characteristically have an initiation factor IF2 gene (infB) H allele and multilocus sequence types that are not found in human GBS strains. Evidence suggests that this "H allele" lineage is related to the human III-3 lineage. These results support the assertion that human and bovine GBS are largely unrelated and provide further insight into the genetic relation between human and bovine GBS.

Alleles↗
PubMed2003

Multilocus sequence typing system for group B streptococcus.

A multilocus sequence typing (MLST) system was developed for group B streptococcus (GBS). The system was used to characterize a collection (n = 152) of globally and ecologically diverse human strains of GBS that included representatives of capsular serotypes Ia, Ib, II, III, V, VI, and VIII. Fragments (459 to 519 bp) of seven housekeeping genes were amplified by PCR for each strain and sequenced. The combination of alleles at the seven loci provided an allelic profile or sequence type (ST) for each strain. A subset of the strains were characterized by restriction digest patterning, and these results were highly congruent with those obtained with MLST. There were 29 STs, but 66% of isolates were assigned to four major STs. ST-1 and ST-19 were significantly associated with asymptomatic carriage, whereas ST-23 included both carried and invasive strains. All 44 isolates of ST-17 were serotype III clones, and this ST appeared to define a homogeneous clone that was strongly associated with neonatal invasive infections. The finding that isolates with different capsular serotypes had the same ST suggests that recombination occurs at the capsular locus. A web site for GBS MLST was set up and can be accessed at http://sagalactiae.mlst.net. The GBS MLST system offers investigators a valuable typing tool that will promote further investigation of the population biology of this organism.

Adult↗
PubMed2002

Cerebral syncope in a patient with spinal cord injury.

An 80-year-old patient suffering from traumatic paraplegia due to spinal cord compression was admitted due to recurrent orthostatic syncope. Tilt table testing revealed that the patient lost consciousness without hypotension. Doppler flow measurements of the middle cerebral arteries showed a significant decrease in diastolic velocity during syncope without systemic hypotension. Treatment with beta-blockers was highly effective. The patient suffered from cerebral blood flow disregulation probably due to abnormal baroreceptor responses triggered during orthostatic stress. This is the first reported case of a patient with spinal cord injury suffering from such an unusual cause of syncope.

Adrenergic beta-Antagonists↗