Evolution of antibiotic resistance of non-typhoidal salmonellae in Greece during 1990-97

Susceptibility to 15 antibiotics was determined in 1548 non-typhoidal salmonella strains isolated in Greece from l990 to l997. The overall prevalence of resistance of both Salmonella enterica serotype Enteritidis and Salmonella enterica serotype Typhimurium increased during the first years of the study. A decrease was observed from 1996, especially for S. Enteritidis, which showed the highest overall antibiotic resistance. S. Typhimurium was the serotype with the highest multiresistance to antibiotics. The rest of the serotypes had very low resistance prevalence compared with both S. Enteritidis and Typhimurium serotypes.     

A nested, multiplex, PCR assay for the simultaneous detection and differentiation of Entamoeba histolytica and Entamoeba dispar in faeces

The detection of and differentiation between Entamoeba histolytica and Entamoeba dispar are of great importance, both for diagnosis and for epidemiological studies. Most PCR-based methods for the discrimination of these two species employ complex procedures for DNA extraction and require different protocols for E. histolytica and E. dispar, leading to relatively high expenditure, labour costs and turnaround times. A simple, rapid, cost-effective and yet sensitive and specific multiplex PCR technique has now been developed for the simultaneous detection and differentiation of E. histolytica and E. dispar in faecal samples. The detection limit is 200 trophozoites of E. dispar or 1000 trophozoites of E. histolytica/g stool sample. The sensitivity of the assay remains practically unchanged, even in the presence of 20,000 trophozoites of the other species/g stool sample. Thus, this technique may also easily reveal mixed infections, without the danger of misdiagnosis caused by one strain displacing the other in culture.     

Comparison of postoperative refractive outcome in eyes undergoing combined phacovitrectomy vs cataract surgery following vitrectomy

Graefe's Archive for Clinical and Experimental Ophthalmology - To investigate the accuracy of preoperative biometry in eyes undergoing combined phacovitrectomy and to compare it with eyes...     

Characterization of Enterobius vermicularis in a human population, employing a molecular-based method from adhesive tape samples

Human infection with the parasitic nematode Enterobius vermicularis occurs worldwide, particularly in children. Although its prevalence may exceed 35% in some parts of the world, molecular studies of E. vermicularis in humans are limited. The aim of the present study was to investigate the genetic variation within E. vermicularis in a human population. For this purpose, 77 adhesive tape samples taken from Greek children infested with E. vermicularis were tested. New primers were designed to amplify a segment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of E. vermicularis from adhesive tape samples. Thirty-six amplicons were sequenced and eleven different haplotypes were identified. All sequences clustered within the type previously characterized (type B), only reported to date from captive chimpanzees. To the best of our knowledge, this is the first study of E. vermicularis genotypes from a human population.     

High sequence divergence in the 5′ non-coding region of reference Coxsackie B and ECHO viral strains and clinical isolates revealed by restriction fragment length polymorphism analysis

We report the restriction fragment length polymorphism (RFLP) patterns of a 440-bp-long 5′ non-coding region (5′NCR) amplification target of all 34 reference Coxsackie B and ECHO (enteric cytopathic human orphan) enterovirus strains and a total of 42 serotypically pre-assigned clinical isolates, in order to afford meaningful comparisons among these patterns and those of polioviruses. The RFLP patterns of reference Coxsackie B strains differed from one another and from those of polio and ECHO reference enteroviruses except from Coxsackie B1 and B2, which, although they differed from one another, had identical RFLP patterns with ECHO 17 and 13, respectively. The 28 ECHO reference strains formed a more variable viral group including strains with RFLP patterns distinct from one another and from those of polio and Coxsackie B enteroviruses, and others with RFLP pattern identities common to other ECHO viruses and Coxsackie B1 and B2 but not polioviruses. The RFLP patterns of the clinical isolates and their corresponding serotypically assigned reference Coxsackie B and ECHO strains presented the most notable variations. The observed differences between serotype and genotype-dependent assignments within the 440-bp long 5′NCR target sequence of Coxsackie B and ECHO enteroviruses were in sharp contrast to the analogous situation with polioviruses. These findings support the specificity of the described method for clinical diagnostic genotyping of polioviruses and demonstrate that the 440-bp-long target sequence follows a different evolutionary process in polio and non-polio enteroviruses that is particularly prominent between reference non-polio strains and their serotypically assigned clinical isolates.     

High sequence divergence in the 5' non-coding region of reference Coxsackie B and ECHO viral strains and clinical isolates revealed by restriction fragment length polymorphism analysis

We report the restriction fragment length polymorphism (RFLP) patterns of a 440-bp-long 5' non-coding region (5' NCR) amplification target of all 34 reference Coxsackie B and ECHO (enteric cytopathic human orphan) enterovirus strains and a total of 42 serotypically pre-assigned clinical isolates, in order to afford meaningful comparisons among these patterns and those of polioviruses. The RFLP patterns of reference Coxsackie B strains differed from one another and from those of polio and ECHO reference enteroviruses except from Coxsackie B1 and B2, which, although they differed from one another, had identical RFLP patterns with ECHO 17 and 13, respectively. The 28 ECHO reference strains formed a more variable viral group including strains with RFLP patterns distinct from one another and from those of polio and Coxsackie B enteroviruses, and others with RFLP pattern identities common to other ECHO viruses and Coxsackie B1 and B2 but not polioviruses. The RFLP patterns of the clinical isolates and their corresponding serotypically assigned reference Coxsackie B and ECHO strains presented the most notable variations. The observed differences between serotype and genotype-dependent assignments within the 440-bp long 5' NCR target sequence of Coxsackie B and ECHO enteroviruses were in sharp contrast to the analogous situation with polioviruses. These findings support the specificity of the described method for clinical diagnostic genotyping of polioviruses and demonstrate that the 440-bp-long target sequence follows a different evolutionary process in polio and non-polio enteroviruses that is particularly prominent between reference non-polio strains and their serotypically assigned clinical isolates.     

Development of a PCR-based method for diagnosis of Leishmania in blood samples

Visceral Leishmaniasis (VL) cases reported in Mediterranean countries and in Northern Europe are becoming increasingly frequent. The past few years several studies have shown Polymerase Chain Reaction to be more effective than the classical methods for the diagnosis of VL in clinical samples. The purpose of this study was the development of a simple, specific and sensitive PCR-based assay for the detection of Leishmania in blood samples. A specific pair of oligonucleotides was designed using conserved sequences of the ssu-rRNA Leishmania infantum gene. Of the 53 blood samples of patients suspected for leishmaniasis that were processed with the newly designed oligonucleotides, 13 were successfully diagnosed positive. The results were confirmed with sequencing and restriction fragment length polymorphism. The lower detection limit of the reported assay was 10 parasites per ml in all seeded samples tested and considered highly satisfactory for diagnosis of Leishmaniasis in blood samples.