The prevalence of upper respiratory symptoms in a cohort of adults presenting with symptoms of gastro-oesophageal reflux disease.

INTRODUCTION: Gastro-oesophageal reflux disease (GORD) is the pathological reflux of gastric contents into the oesophagus. The oesophagus and the upper respiratory tract have a common origin from the foregut. There is increasing evidence for multiple associations of GORD with the upper respiratory tract. OBJECTIVES: To study the presence of and association of upper respiratory symptoms (URS) with GORD. METHODS: Seventy adults scoring ≥12.5 on a previously validated GORD symptom score (GORD patients) and 70 healthy controls who had infrequent GORD symptoms or no upper gastro-intestinal complaints completed a pre-tested URS questionnaire on the frequency of 14 URS in 5 categories (laryngeal, nasal, pharyngeal, sinusal and aural). All GORD patients underwent upper gastro-intestinal endoscopy. The calculated URS score was correlated against the GORD symptom score and endoscopy findings. RESULTS: URS scores and individual symptom scores were higher in GORD patients compared to controls (mean ± SE, 4.7 ± 4.0; 1.9 ± 2.3). Individuals with higher GORD symptom scores reported more frequent URS. Pharyngeal symptoms had the highest correlation with the GORD symptom score (r=0.507, p<0.001). The presence of oeso-phagitis did not seem to influence the frequency of reporting URS. CONCLUSION: Upper respiratory symptoms are common in individuals with GORD symptoms though there appears to be no association with oesophageal mucosal damage.

Influence of freezing-thawing and refrigeration on R-plasmid (pRPJ24) stability in Enterobacter cloacae 94R.

The effect of twenty freezing (-20 degrees C) and thawing cycles of Enterobacter cloacae 94R cells containing the R-plasmid pRPJ24 inoculated into broth and ground beef meat samples revealed no loss of resistance due to plasmid instability. In addition, low temperature storage at 4 degrees C did not produce any significant loss of the tetracycline and kanamycin resistances encoded on the pRPJ24 plasmid. The results of this study indicated that indigenous R-plasmids like pRPJ24 are stable in resident recipients like E. cloacae 94R in ground beef. However, the proportion of viable cells containing the pRPJ24 plasmid decreased significantly after 20 freezing-thawing cycles over 14 days incubation at 4 degrees C.

Occurrence of aminoglycoside phosphotransferase subclass I and II structural genes among Enterobacteriaceae spp. isolated from meat samples.

3'-Aminoglycoside phosphotransferase [APH(3')] enzymes are a group responsible for resistance to the antibiotics kanamycin (Km) and neomycin (Nm) in bacteria. Escherichia coli ECT24, originally isolated from a meat sample, harboured an 83-kb conjugative R-plasmid (pRPJ24) that carries transferable resistance to Km and Nm. Plasmid pRPJ24 was transferred by conjugation to Enterobacter cloacae 94R, which was used as the source of plasmid DNA in development of a probe for the Km-resistance determinant. Random cloning of BamHI and HindIII double-digest restriction fragments of pRPJ24 in the pUC18 vector plasmid produced clones resistant to both Nm and Km carrying a 1.9-kb DNA insert. Southern hybridization of pRPJ24 cloned chimeric plasmid DNA (pKPJ94) showed homology with the APH(3')II gene from transposon Tn5. A PstI digest of pKPJ94 produced a 920-bp fragment which hybridized with the APH(3')II structural gene, and was used as a DNA probe for the APH(3')II subclass gene. A 980-bp BamHI fragment from plasmid pGH54 carrying the APH(3')I gene from transposon Tn903 was used as a subclass I probe. Total DNA from 206 randomly screened Km-resistant Enterobacteriaceae isolates from raw ground beef and chicken meat samples were examined for the occurrence of APH(3') subclass I and II using non-radioactively-labelled DNA probes. Thirty-six percent and 60% of the isolates examined carried subclass I and II resistances, respectively, in the isolates from chicken meat samples. The corresponding values for bacterial strains from raw ground beef samples were 51% and 72%, respectively. Four percent of the resistant bacterial isolates from chicken samples did not display homology to either probe.(ABSTRACT TRUNCATED AT 250 WORDS)