Background: Paromomycin is used for selective bowel decontamination (SBD) in patients undergoing bone marrow transplantation in many hospitals, but there are no published resistance data for this compound in the recent medical literature. The aim of this study was to investigate the in vitro activity of paromomycin against the common intestinal bacteria E. coli and P. aeruginosa.Methods: 94 E. coli isolates and 77 P. aeruginosa isolates derived from clinical specimens were tested by broth microdilution against paromomycin and amikacin, respectively, following the CLSI recommendations for testing amikacin.Results: 86 of 94 E. coli isolates (91%) and 71 of 77 P. aeruginosa isolates (92%) showed in vitro susceptibility to amikacin (MIC90 for both compounds 16 mu g/ml, range: 1-32 mu g/ml for E. coli and 1->128 mu g/ml for P. aeruginosa). Paromomycin was active against 83/94 E. coli isolates (88%; MIC90: 32 mu g/ml, range: 2->128 mu g/ml), but showed poor in vitro activity against P. aeruginosa (3/77 isolates susceptible [4%]; MIC90: > 128 mu g/ml, range: 2->128 mu g/ml).Conclusion: If SBD with inclusion of an aminoglycoside antibiotic is applied, paromomycin should not be used unless local resistance data provide evidence of a sufficient in vitro activity of this compound against P. aeruginosa.

Background: The aim of this study was to investigate the decontamination capacity of 4 different types of cleaning cloths (microfiber cleaning cloth, cotton cloth, sponge cloth, and disposable paper towels) commonly used in hospital in their ability to reduce microbial loads from a surface used dry or wet in new condition. All of the cloths except disposable paper towels were also compared after 10 and 20 times of reprocessing, respectively, at 90 degrees C for 5 minutes in a washing machine.Methods: Stappylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 8739) were used as test organisms. Test organisms were then added to a test soil (6% bovine serum albumin and 0.6% sheep erythrocytes) resulting in a controlled concentration of 5x10(7) colony-forming units per milliliter in the final test suspension. Standardized tiles measuring 535 cm were used as test surface.Results: Microfiber cloths showed the best results when being used in new condition. However, after multiple reprocessing, cotton cloth showed the best overall efficacy.Conclusion: We therefore suggest that the choice of the cleaning utilities should be based on their decontamination efficacy after several reprocessings and recommend the establishment of strict and well-defined cleaning and disinfection protocols.

The physical capacity of negative pressure wound therapy (NPWT) dressing on the bacterial growth in an in vitro wound model was investigated. Standardised wounds were contaminated with a clinical Staphylococcus aureus strain and incubated at 35 degrees C for 6 hours. Four wounds were treated with continuous negative pressure (125 mmHg) and four controls without. Bacterial load per gram tissue and per gram polyurethane sponge were measured after 24, 36 and 72 hours. Without negative pressure, the initial mean S. aureus load per gram tissue was 1.42 x 10(4), with negative pressure 1.84 x 10(4), P = 0.294. After 24, 36 and 72 hours, both models yielded comparable numbers of organisms (24 hours: P = 0.081; 48 hours: P = 0.455; 72 hours: P = 0.825, respectively). Bacterial load of sponges with or without negative pressure also did not differ. Over a period of 72 hours, sponges with negative pressure yielded 1.60 x 108, those without negative pressure yielded 1.74 x 10(8) CFU/g sponge (P = 0.876). In non vital tissue without the influence of the immune system, the bacterial load did not decrease in our in vitro model using an NPWT dressing. This observation was independent of the physical effect of continuous negative pressure at 125 mmHg. The reduction in bacteria demonstrated in previous studies appears to be caused by other effects than physical suction alone. However, the results obtained are limited as non viable tissue was used and the effect of suction on dead tissue might be very different from that occurring on perfused tissue, for example, in an animal model or in patients.

Background: The surface of polymeric tracheotomy tubes is a favourable environment for biofilm formation and therefore represents a potential risk factor for the development of pneumonia after tracheotomy. The aim of this in-vitro study was to develop octenidine-dihydrochloride (OCT) coated polymer tracheotomy tubes and investigate any effects on Staphylococcus (S.) aureus and Pseudomonas (P.) aeruginosa colonization. Additionally the resistance of the OCT coating was tested using reprocessing procedures like brushing, rinsing and disinfection with glutaraldehydeResults: Contamination with S. aureus: Before any reprocessing, OCT coated tracheotomy tubes were colonized with 10(3) cfu/ml and uncoated tracheotomy tubes with 10(5) cfu/ml (P = 0.045). After reprocessing, no differences in bacterial concentration between modified and conventional tubes were observed.Contamination with P. aeruginosa: Before reprocessing, OCT coated tubes were colonized with 10(6) cfu/ml and uncoated tubes with 10(7) cfu/ml (P = 0.006). After reprocessing, no significant differences were observed.Conclusion: OCT coating initially inhibits S. aureus and P. aeruginosa colonisation on tracheotomy tubes. This effect, however, vanishes quickly after reprocessing of the tubes due to poor adhesive properties of the antimicrobial compound. Despite the known antimicrobial effect of OCT, its use for antimicrobial coating of tracheotomy tubes is limited unless methods are developed to allow sustained attachment to the tube.

BACKGROUND:Vancomycin-resistant entrococci (VRE) are increasing in prevalence at many institutions, and are often reported in dialysis patients. The aim of this cross-sectional prevalence study was to determine the prevalence and risk factors of VRE colonization in chronic hemodialysis patients in two hemodialysis centers in Shiraz, Iran.METHODS:Rectal swabs were obtained from all consenting patients and were streaked on the surface of Cephalexin-aztreonam-arabinose agar (CAA) and incubated at 37 degrees C in air for 24 h. The vancomycin susceptibility of each isolate was confirmed by disk susceptibility testing. The MICs of vancomycin and teicoplanin were confirmed by the E test. To identify risk factors, a questionnaire was completed for all the studied patients and the data of VRE positive and negative groups were compared using Man-Withney U test for continues data and the Fisher exact test for categorical data.RESULTS:Of 146 patients investigated, 9 (6.2%) were positive for VRE. All VRE strains were genotypically distinguishable. Risk factors for a VRE-positive culture were "antimicrobial receipt within 2 months before culture" (P = 0.003) and "hospitalization during previous year" (P = 0.016).CONCLUSION:VRE colonization is an under-recognized problem among chronic dialysis patients in Iran. VRE colonization is associated with antibiotic consumption and hospitalization.

There are few data on detection of Mycoplasma pneumoniae from blood, serum or plasma, and systematic studies on this diagnostic approach in community-acquired pneumonia (CAP) are scarce. Compared to testing respiratory specimens, this approach has the advantages that it is less dependent on proper specimen collection, serum is easily stored and handled, and the pathogen is detected in a primary sterile site, where colonization can be ruled out. In this study, acute-phase serum specimens from 29 patients of Vienna University Hospital (treated between 11/1994 and 6/2004; female: 14, male: 15; median age: 31 years, range: 15–66 years) with CAP and serologically verified M. pneumoniae infection, who had not received anti-mycoplasma therapy prior to serum collection, were tested for M. pneumoniae by conventional PCR and real-time PCR. Conventional PCR yielded negative results for all specimens, but real-time PCR detected M. pneumoniae in 15/29 patient sera (52%). These findings indicate that M. pneumoniae is present in the bloodstream of a substantial proportion of patients with mycoplasma pneumonia. Despite the possible adherence of M. pneumoniae to human erythrocytes, the pathogen can be detected from serum, if a method with enhanced sensitivity is applied. However, the negative predictive value of PCR from serum with regard to etiological diagnosis is low. With regard to the potential clinical benefit of blood-based PCR diagnosis of mycoplasma pneumonia the diagnostic accuracy of this approach using either serum or whole-blood specimens should be addressed by large-scale studies.

OBJECTIVES:Mycoplasma hominis and Ureaplasma urealyticum are associated with various diseases of the urogenital tract, but they are usually not detected by routine microbiological diagnosis. The aim of this study was to asses the prevalence of these organisms in patients with sterile pyuria. METHODS:From December 2000 to June 2001 all urine samples sent in to microbiological diagnosis, which yielded > or =500 leucocytes/ml and <10(4) bacteria/ml, were collected for this study. Thirty-three samples from 30 patients (female: 21, male: nine; median age: 60 years, range: 23-91 years) met these criteria and were subjected to PCR for detection of M. hominis and U. urealyticum, respectively. RESULTS:M. hominis and U. urealyticum were detected in 2 (7%) and 6 samples (20%), respectively. With regard to the underlying diseases of the patients, glomerulonephritis was significantly associated with the detection of urogenital mycoplasmas (p=0.02). CONCLUSION:The prevalence of M. hominis and U. urealyticum found in this study corresponds to the expected prevalence in the general population. This finding does not indicate an association of sterile pyuria with urogenital mycoplasma infection/colonization.

Ralstonia mannitolilytica strains isolated between February 2002 and March 2004 from 30 episodes of infection in 26 patients at Vienna University Hospital were characterized. Twenty-four of the episodes occurred within a 7 month period, suggesting they were outbreak-related, although no common source of infection was identified. The isolates were assayed using PCR to confirm species identification. Random amplification of polymorphic DNA (RAPD) typing classified the R. mannitolilytica isolates into four distinct genotypes: A/I, B/II, C/III and D/IV (15, 13, 1 and 1 isolates, respectively). API 20NE, VITEK Gram-negative Identification Card plus (GNI+) and VITEK Gram Negative Bacillus Identification (GNB) yielded negative or no acceptable biochemical profile for 4, 11 and 11 isolates, respectively. None of the isolates acidified D-arabitol or mannitol. Two isolates (7 %) were positive for nitrate reduction. All 30 R. mannitolilytica isolates were resistant to desferrioxamine, and 29 were able to grow on BCSA. The most active compounds in vitro were ciprofloxacin and cefepime, whilst only the genotype D/IV isolate was sensitive to gentamicin and amikacin (the remaining 29 isolates being resistant to both).