Burkholderia cepaciaInfections Associated With Intrinsically Contaminated Ultrasound Gel: The Role of Microbial Degradation of Parabens

Outbreaks where food workers have been implicated in the spread of foodborne disease. Part 10. Alcohol-based antiseptics for hand disinfection and a comparison of their effectiveness with soaps

Alcohol compounds are increasingly used as a substitute for hand washing in health care environments and some public places because these compounds are easy to use and do not require water or hand drying materials. However, the effectiveness of these compounds depends on how much soil (bioburden) is present on the hands. Workers in health care environments and other public places must wash their hands before using antiseptics and/or wearing gloves. However, alcohol-based antiseptics, also called rubs and sanitizers, can be very effective for rapidly destroying some pathogens by the action of the aqueous alcohol solution without the need for water or drying with towels. Alcohol-based compounds seem to be the most effective treatment against gram-negative bacteria on lightly soiled hands, but antimicrobial soaps are as good or better when hands are more heavily contaminated. Instant sanitizers have no residual effect, unlike some antimicrobial soaps that retain antimicrobial activity after the hygienic action has been completed, e.g., after hand washing. Many alcohol-based hand rubs have antimicrobial agents added to them, but each formulation must be evaluated against the target pathogens in the environment of concern before being considered for use. Wipes also are widely used for quick cleanups of hands, other body parts, and surfaces. These wipes often contain alcohol and/or antimicrobial compounds and are used for personal hygiene where water is limited. However, antiseptics and wipes are not panaceas for every situation and are less effective in the presence of more than a light soil load and against most enteric viruses.

Use of sterile saline as a conduction agent for ultrasound visualization of central venous structures

OBJECTIVE

To determine whether sterile saline as a conduction agent provides adequate visualization of anatomic structures to attempt ultrasound-guided vascular access.

METHODS

This prospective study involved a convenience sample of adult patients (18 years and older) who presented to an urban academic ED during a 3-month study period. Each patient had three six-second ultrasound video clips obtained of the right internal jugular vein and surrounding structures utilizing three different conduction agents, water-based gel (the control), sterile saline or no conduction agent. Video clips were randomized and assigned a numeric code to blind reviewers to the conduction agent. They were then independently reviewed by two experts who determined whether anatomic structures were visualized with enough detail to perform ultrasound-guided vascular access. The reviewers also rated the overall image quality of each video clip using a 100 mm visual analogue scale (VAS).

RESULTS

Forty-seven patients were included in the final analysis. The raw agreement was 100% (95% confidence intervals [CI]: 93-100%) with a kappa of 1.0 between the two reviewers in assessing whether they would be able to perform vascular access using the images obtained using saline as a conduction agent. The median VAS for gel across both reviewers was 92 (95% CI: 90-93) and the median VAS differences for saline and no medium were -3 (95% CI: -1 to -3) and -46 (95% CI: -22 to -61), respectively.

CONCLUSIONS

The use of sterile saline as a conduction agent allows adequate visualization of anatomic structures to attempt ultrasound-guided vascular access.

The changing microbial epidemiology in cystic fibrosis

Infection of the airways remains the primary cause of morbidity and mortality in persons with cystic fibrosis (CF). This review describes salient features of the epidemiologies of microbial species that are involved in respiratory tract infection in CF. The apparently expanding spectrum of species causing infection in CF and recent changes in the incidences and prevalences of infection due to specific bacterial, fungal, and viral species are described. The challenges inherent in tracking and interpreting rates of infection in this patient population are discussed.

Infection Control in the Sonography Department

Knowledge of how to prevent healthcare-associated infections within the sonography department is an important step in providing quality care. Employing scientifically based preventative measures will ensure that the tools we use do not become vectors for the spread of pathogens that cause infections. These avoidable infections have not only an added financial cost to patients and the already burdened healthcare system but also physical and emotional costs to the patients we treat. Specific infection control guidelines for the sonography department are lacking, and the guidelines that are available are often based on proven infection control practiced in similar situations. Within this article are the applicable infection guidelines sonographers can use to provide safe quality care.

Degradation of parabens by Pseudomonas beteli and Burkholderia latens

p-Hydroxybenzoic acid esters (parabens) are commonly used antimicrobial preservatives in pharmaceutical formulations. Two microorganisms, isolated from non-sterile methyl paraben (MP) and propyl paraben (PP) solutions, were found to degrade the respective parabens. Identification by 16S rRNA partial gene sequencing revealed them to be Pseudomonas beteli and Burkholderia latens, respectively. The present work describes a previously unreported interaction of the parabens with P. beteli and B. latens. Degradation of MP at various concentrations by P. beteli, followed a logarithmic pattern, while that of PP by B. latens was found to be linear. It was subsequently observed that P. beteli could degrade only MP, while B. latens could degrade both the parabens. Absence of HPLC chromatogram peaks of expected degradation products indicated that the parabens were used up as a carbon source. The behaviour of pathogens (Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus niger) of the pharmacopoeial preservative effectiveness test (PET), towards MP, showed that none had the ability to degrade the paraben. It was concluded that, for a paraben-preserved multi-dose ophthalmic formulation, the sole use of the four pathogens that are recommended by the pharmacopoeia for PET can falsely indicate the formulation to be effective against 'in-use' contamination.

Repression of common bull sperm flora and in vitro impairment of sperm motility with Pseudomonas aeruginosa introduced by contaminated lubricant

Semen collected from clinically healthy bulls at an artificial insemination centre was examined for bacterial diversity. While bacteria that are normally present in the common flora of bovine semen were absent, such as Mycoplasma sp., Proteus sp. and Corynebacterium sp., all semen samples contained an unusually high number of Pseudomonas aeruginosa strains. Analysis via pulsed field gel electrophoresis demonstrated that one particular P. aeruginosa strain, present in a sealed bottle of lubricant, was widespread in bull semen. This strain was shown to secrete substances that inhibited both the growth of bacteria constituting the normal bull sperm flora and the motility of spermatozoa in vitro. This study demonstrated that commercially available lubricants might contain bacteria that can spread amongst breeding bulls and affect the quality of semen. Bacteriological controls and species' identification are necessary at several production levels, including lubricants and extenders, to ensure high semen quality and avoid the spread of pathogens.

Does prebiopsy, nonsterile ultrasonography gel affect biopsy-site asepsis?

PURPOSE

The purpose of this study was to determine the extent to which the use of nonsterile gel, prior to antiseptic procedures in ultrasonography (US)-guided percutaneous biopsies, results in contamination of the biopsy site.

MATERIALS AND METHODS

Patients referred for US-guided percutaneous biopsies were included in this study. Transmission material used for US evaluation before biopsy-site antiseptic procedures were performed was either nonsterile gel or sterile saline. Patients were randomly assigned to two groups: nonsterile gel (n = 30) and sterile saline (n = 30). Before the transmission material was used and after antiseptic procedures were performed, microbial swabs of a 10-cm(2)-diameter area were obtained at the biopsy site. Swabs were also obtained from the gel, saline, and povidine-iodine. Inoculated specimen plates were incubated at 37 degrees C under aerobic conditions, and the numbers of colony-forming units recorded. Nominal logistic regression analysis was used to calculate the odds of postantisepsis bacterial growth (after antiseptic procedures were performed) based on group, gender, coincidental disease (diabetes, chronic renal failure, and malignancy), biopsy-site location (head and neck or breast and abdomen), and local factors (skin fold, skin tag, and hair).

RESULTS

The following odds ratios (adjusted for the other variables) and their 95% confidence intervals were calculated: (1) group (2.9 [0.8-11.1]; p = 0.10); (2) gender (1.2 [0.3-5.2]; p = 0.78); (3) coincidental disease (7.6 [0.9-166.7]; p = 0.09); (4) biopsy site location (6.2 [1.4-31.3]; p = 0.02); and (5) local factors (7.0 [1.6-36.0]; p = 0.01). No bacterial growth occurred with swabs obtained from gel, povidine-iodine, or saline.

CONCLUSION

We conclude that nonsterile gel used prior to percutaneous biopsy does not affect biopsy-site asepsis.

Condom perforation during transrectal ultrasound guided (TRUS) prostate biopsies: a potential infection risk

INTRODUCTION

Transrectal ultrasound (TRUS) guided prostate biopsies are amongst the most common outpatient diagnostic procedures performed in urology practice. Of concern appear to be recent reports of infectious complications following this procedure in which contamination of the biopsy equipment was the likely source. This study looks at the rate of condom perforation during prostate biopsy and we look to highlight the potential problems, which may arise as a result of inadequate cleansing of the equipment between cases during a busy prostate biopsy clinic

MATERIAL AND METHODS

All patients attending for prostate biopsies over a three-month period in our institution were included in the study. All condoms (latex) used were made by the same manufacturer and were checked prior to the procedure and found to have no leaks. The biopsy gun was inserted through an externally placed needle guide, as is standard practice in many departments in the UK. After the end of each procedure the condom was removed from the rectal probe and filled once again with water to assess for perforations. Two experienced surgeons carried out all the procedures.

RESULTS

10 out of 107 patients were found to have at least one perforation in the condom. In some of the condoms there were multiple perforations.

DISCUSSION

We have demonstrated a significant condom perforation rate (9%) amongst patients undergoing prostate biopsies. This raises the serious issue of hygiene and cross infection, particularly with blood borne communicable diseases such as hepatitis and HIV unless strict disinfection and sterilization protocols are followed between patients. Perforation of the condoms used during TRUS guided prostate biopsy and hence faecal and blood contamination of the biopsy equipment could potentially have far-reaching implications for urologists and the infection control community. Although the risk of cross infection is probably small this serious issue needs addressing.

Outbreak of Pseudomonas aeruginosa Infections After Transrectal Ultrasound-Guided Prostate Biopsy

OBJECTIVES

After the Georgia Department of Human Resources Division of Public Health was notified about 4 patients who were hospitalized with Pseudomonas aeruginosa infections after outpatient transrectal ultrasound-guided prostate biopsies in July 2005, we investigated the cause of, and risk factors for, the infections.

METHODS

We enhanced surveillance for additional cases, reviewed medical records, evaluated biopsy equipment and infection control practices, and collected environmental samples. Transrectal ultrasound-guided prostate biopsy procedures were discontinued during the investigation.

RESULTS

A total of 4 cases were identified. All patients were men aged 57 to 71 years. All 4 recovered with antimicrobial therapy. P. aeruginosa was isolated from the narrow lumen of the steel biopsy needle guide that had been soaking in high-level disinfectant for several days. The needle guide isolate and three available clinical isolates were indistinguishable by pulsed-field gel electrophoresis. A review of the reprocessing procedures of the biopsy needle guide revealed that it was disinfected by submersion in high-level disinfectant rather than sterilization, the reprocessing procedure recommended by the manufacturer. Manual cleaning of the lumen was limited to flushing. After disinfection, the guide was rinsed with nonsterile tap water.

CONCLUSIONS

The outbreak resulted from a contaminated needle guide. The needle guide reprocessing procedures were inadequate. Potential causes of P. aeruginosa contamination include the lack of adequate manual cleaning before disinfection, failure to sterilize the needle guide, and the use of a tap-water rinse after disinfection. Clinicians performing transrectal ultrasound-guided prostate biopsy procedures should follow the manufacturers' needle guide reprocessing recommendations or use disposable needle guides.

Evaluation of a new disinfection procedure for ultrasound probes using ultraviolet light

Following 183 ultrasound examinations, a randomized trial was conducted to compare three procedures for disinfection of probes under routine conditions: dry wiping with a soft, dry, non-sterile paper towel, antiseptic wiping with a towel impregnated with disinfectant spray and dry wiping followed by a 10 min ultraviolet C (UVC) cycle in a disinfection chamber. After ultrasonography, swabs were taken from transducer heads before and after cleaning and streaked onto plates that were then cultured. The number of colonies per plate was counted and organisms identified. The median microbial reduction was 100% for UVC, 98.4% for antiseptic wiping and 87.5% for dry wiping (P<0.001). The percentage of negative specimens was 88% for UVC, 16% for antiseptic wiping and 4% for dry wiping (P<0.0001). Microbial flora was isolated from 12 probes (6.6%) before cleaning, whereas specimens obtained after cleaning contained no pathogens except in one case after antiseptic wiping. UVC disinfection of ultrasound probe may provide a useful method for reducing the bacterial load under routine conditions.

Hospital-acquired infections related to contaminated substances

Drug-related outbreaks are frequently reported from various medical departments. A systematic review was performed to describe characteristics of these outbreaks and to determine the most frequent occasions in which contamination of substances for patient care take place. Articles were assessed by a search of the outbreak database, a search of PubMed, and hand search of reference lists from relevant articles. Articles published before 1990 were excluded. Data on affected patients, hospital-acquired infections, substances, pathogens and graded information about the location of the contamination incidence were extracted. A total of 2250 patients in 128 articles were included, mostly from intensive care units or haematological departments. Septicaemia was the most frequent hospital-acquired infection. Most often articles report contamination of blood products and heparin-sodium chloride solutions. The most frequent pathogens were hepatitis A virus, Yersinia enterocolitica, and Serratia spp. for blood products and Burkholderia cepacia and Enterobacter spp. for substances other than blood products. Mortality was highest if red blood cells or total parenteral nutrition formulas were contaminated. In 64 of the outbreaks multi-dose vials had been used against the manufacturers' recommendations. Thus, drug-related outbreaks are likely to occur particularly when basic hygiene measures are disobeyed. A large proportion of drug-related nosocomial infections could have been prevented, for example, by avoiding the use of multi-dose vials.

Sustained endemicity of Burkholderia cepacia complex in a pediatric institution, associated with contaminated ultrasound gel

OBJECTIVE

To determine whether contaminated ultrasound gel is the source of intermittent outbreaks of nosocomial infection due to Burkholderia cepacia complex in patients without cystic fibrosis since 1992.

DESIGN

A prospective clinical and in vitro study of all in-use bottles of ultrasound gel, as well as a retrospective analysis of archived bacterial strains, were performed. Handling of gel for clinical purposes throughout the hospital was evaluated. Gel and archived clinical isolates of B. cepacia complex were speciated to genomovar level and characterized by pulsed-field gel electrophoresis, and the pulsed-field gel electrophoresis patterns were compared.

SETTING

The Hospital for Sick Children, a 300-bed, tertiary care, pediatric academic health sciences center in Toronto, Canada.

PATIENTS

All patients without cystic fibrosis from whom B. cepacia complex was recovered at the Hospital for Sick Children since 1992.

RESULTS

No standardized protocol for storage or handling of ultrasound gel was found. Gel from 39% of bottles grew either B. cepacia (genomovar I) or Burkholderia stabilis (genomovar IV). These isolates had pulsed-field gel electrophoresis patterns identical to 2 of the 7 clinical pulsed-field gel electrophoresis types that are responsible for 88% of clinical isolates.

CONCLUSIONS

Contaminated ultrasound gel contributed to nosocomial infection due to B. cepacia complex in this institution over the course of 10 years. Suggested guidelines for the handling of ultrasound gel are provided.

Update on the Burkholderia cepacia complex

PURPOSE OF REVIEW

The Burkholderia cepacia complex is comprised of a group of related bacterial species that are capable of causing life-threatening respiratory tract infection in persons with cystic fibrosis. This article reviews advances in our understanding of Burkholderia cepacia complex infection in cystic fibrosis, focusing on the taxonomy, clinical microbiology, and epidemiology, as well as the natural history and clinical outcomes associated with Burkholderia cepacia complex infection.

RECENT FINDINGS

Each of the nine species of the Burkholderia cepacia complex has now received a formal species name. These names are the preferred nomenclature, replacing the former 'genomovar' designations. Studies from several countries reiterate that two species, Burkholderia cenocepacia and Burkholderia multivorans, account for most Burkholderia cepacia complex infection in cystic fibrosis. Bacterial genotyping studies indicate that specific Burkholderia cepacia complex strains infect multiple cystic fibrosis patients, implying that they may have an enhanced capacity for interpatient spread. Emerging clinical outcomes data suggest that at least some of these so-called transmissible or epidemic strains are also more virulent in the cystic fibrosis host. Ongoing research is aimed at gaining a better understanding of Burkholderia cepacia complex ecology, defining Burkholderia cepacia complex virulence factors and pathogenic mechanisms, and determining the relative virulence of distinct strains.

SUMMARY

Significant advances in our understanding of the Burkholderia cepacia complex serve as a critical foundation for further efforts that ultimately will enable better infection control and the development of novel therapeutics to treat Burkholderia cepacia complex infection in persons with cystic fibrosis.