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Detection of capnocytophaga species in simulated blood cultures by bactec-NR
MICROBIOLOGY DEITATION O F CAPNOCYTOPHAGA SPECIES IN SIMULATED B M O D CULTURES BY BACTEC-NR
D Mitchell*, M Yuen, R bsaitis, Clinical Microbiology Unit, I.C.P.M.R., Westmead Hospital, Westmead N S W 2145.
Capnocytophaga is a genus of Gram negative, fusiform, capnophilic bacteria which are part of the normal oral flora of man and animals. They are rare causes of bacteraemia particularly in neutropenic patients. C.canimorsus (formerly DF-2) may cause overwhelming sepsis following animal bites. A study using clinical isolates of C. ochracea and C. canimorsus in simulated blood cultures was performed to dctermine the sensitivity of detection by BACEC-NR. 48 hour HBA cultures were harveste and oculated into BHI broth. Serial ten fold dilutions were performed (10 to 10 CFUlml) and 6A and 7A BACTZC bott!es were inoculated along with 5 ml of sterile human blood. A Growth Index of > 35 was taken as a positive signal. The resulk suggest that C. ocliracea should be detectable by B A C E C using standard procedures as long as cultures were processed beyond 5 days. C. canimorsus however may not signal up to 7 days and requires terminal subculture. Some strains of C. canimorsus are inhibited by SPS in the blood culture media and require blind subculture within 48 hours or possibly the use of SPS free media.
8 t r
THE BLOOD GAS ANALYSER - A SOURCE OF NOSOCOMIAL GRAM-NEGATIVE INFECTION I N THE INIENSIVE CARE UNIT. J.H. Andrew', S . Dixsonl, P. Charles', C.J.Parslow2, J.D. Santamaria3, Departments of Microbiology1 and Chemical Pathoilogy2 and the Intensive Care Unit3, St. Vincent's Hospital, Melbourne, Vic. 3065.
An outbreak of Xanthomonas maltoDhilia infection involving intensive care patients was traced to a blood gas analyser housed within the Unit. Despite the introduction of measures to try and prevent transmission of organisms by Unit staff from the analyser to patients and the development of protocols for maintenance, decontamination and disposal of effluent from the machine by Chemical Pathology staff, sporadic cases of infection continued. Further investigation of the analyser and an identical laboratory based machine revealed widespread internal contamination of both =?its with a range of water associated Gram-negative bacilli of knc,wn pathogenic potential. These included Pseudomonas aemgiiosa, Ps. ceuacia, Ps. fluorescens, Ps. picketti and X. maltoohilia. Although enadication of bacteria fYom the analysers has proved extremely difficult, control measures adopted have proved effective. Attention is drawn to the real and often not appreciated hazard that this type of equipment can pose to patient,sin intensive care units. Presenter: Dr. John H. Andrew, Microbiology Department, SVH.
MONITORING THE ADEQUACY OF CLEANING AND FOR FLEXBLE DISINFECTON PROCEDURES ENDOSCOPES
J.H. Andrew1, S. Dixsonl, C.M. Pollittz, Departments of Microbiology' and Gastrwnterologyz, St. Vincent's Hospital, Melbourne, Vic. 3065.
AEROMONAS INFECTION IN SIX CASES OF TRAUMA ASSOCIATED WITH WATER.
R. Bunter and J.H. Andrew, Department of Microbiology, St. Vincent's Hospital, Melbourne, Vic. 3065.
Gastrointestinal endoscopic procedures have increased in both number and complexity since the introduction of flexible fibreoptic instruments in the early 1970s. Infection of patients as a result of inadequate cleaning or disinfection of these instruments is well documented. Although much attention has quite rightly been devoted to developing cleaning and disinfection procedures, scant attention has been paid to monitoring the practical effectiveness of such protocols in the clinical setting. A simple sampling technique to recover viable bacteria &om disinfected endoscopes was introduced. This has been routinely applied on a monthly basis over a 3-year period in a Gastroenterology Depamnent which performs over 2,500 endoscopies a year. Despite the diligent application of comprehensive cleaning and disinfection protocols, bacteriological monitoring detected rectifiable failures in disinfection that would otherwise have gone unrecognised.
Aeromonas suecies are water organisms that may cause gastroenteritis and septicaemia, particularly in the immuncucompromised. They have been less frequently described as a cause of wound infection. We report 6 cases of severe wound infection with these organisms which were associated with major trauma and water. In our experience, such infections are more likely to occur in young males d u n n g rhe summer months. The severity of infection was determined primarily by the extent of the underlying injury and in h s setting, Aeromonas SDD. may be isolated as a component of apolymicrobial infection. Antimicrobial treatment u1 the absence of adequate surgical debridenlent was often unsuccessful. When treating trauma associated with water, the anthicrohial regimen used should include cover for Aeromonas SUD.
Presenter: Dr. John H. Andrew, Microbiology Department, SVH.
Presenter: Dr. Richard Bunter, Microbiology Department, SVH.
D Mitchell*, M Yuen, R bsaitis, Clinical Microbiology Unit, I.C.P.M.R., Westmead Hospital, Westmead N S W 2145.
Capnocytophaga is a genus of Gram negative, fusiform, capnophilic bacteria which are part of the normal oral flora of man and animals. They are rare causes of bacteraemia particularly in neutropenic patients. C.canimorsus (formerly DF-2) may cause overwhelming sepsis following animal bites. A study using clinical isolates of C. ochracea and C. canimorsus in simulated blood cultures was performed to dctermine the sensitivity of detection by BACEC-NR. 48 hour HBA cultures were harveste and oculated into BHI broth. Serial ten fold dilutions were performed (10 to 10 CFUlml) and 6A and 7A BACTZC bott!es were inoculated along with 5 ml of sterile human blood. A Growth Index of > 35 was taken as a positive signal. The resulk suggest that C. ocliracea should be detectable by B A C E C using standard procedures as long as cultures were processed beyond 5 days. C. canimorsus however may not signal up to 7 days and requires terminal subculture. Some strains of C. canimorsus are inhibited by SPS in the blood culture media and require blind subculture within 48 hours or possibly the use of SPS free media.
8 t r
THE BLOOD GAS ANALYSER - A SOURCE OF NOSOCOMIAL GRAM-NEGATIVE INFECTION I N THE INIENSIVE CARE UNIT. J.H. Andrew', S . Dixsonl, P. Charles', C.J.Parslow2, J.D. Santamaria3, Departments of Microbiology1 and Chemical Pathoilogy2 and the Intensive Care Unit3, St. Vincent's Hospital, Melbourne, Vic. 3065.
An outbreak of Xanthomonas maltoDhilia infection involving intensive care patients was traced to a blood gas analyser housed within the Unit. Despite the introduction of measures to try and prevent transmission of organisms by Unit staff from the analyser to patients and the development of protocols for maintenance, decontamination and disposal of effluent from the machine by Chemical Pathology staff, sporadic cases of infection continued. Further investigation of the analyser and an identical laboratory based machine revealed widespread internal contamination of both =?its with a range of water associated Gram-negative bacilli of knc,wn pathogenic potential. These included Pseudomonas aemgiiosa, Ps. ceuacia, Ps. fluorescens, Ps. picketti and X. maltoohilia. Although enadication of bacteria fYom the analysers has proved extremely difficult, control measures adopted have proved effective. Attention is drawn to the real and often not appreciated hazard that this type of equipment can pose to patient,sin intensive care units. Presenter: Dr. John H. Andrew, Microbiology Department, SVH.
MONITORING THE ADEQUACY OF CLEANING AND FOR FLEXBLE DISINFECTON PROCEDURES ENDOSCOPES
J.H. Andrew1, S. Dixsonl, C.M. Pollittz, Departments of Microbiology' and Gastrwnterologyz, St. Vincent's Hospital, Melbourne, Vic. 3065.
AEROMONAS INFECTION IN SIX CASES OF TRAUMA ASSOCIATED WITH WATER.
R. Bunter and J.H. Andrew, Department of Microbiology, St. Vincent's Hospital, Melbourne, Vic. 3065.
Gastrointestinal endoscopic procedures have increased in both number and complexity since the introduction of flexible fibreoptic instruments in the early 1970s. Infection of patients as a result of inadequate cleaning or disinfection of these instruments is well documented. Although much attention has quite rightly been devoted to developing cleaning and disinfection procedures, scant attention has been paid to monitoring the practical effectiveness of such protocols in the clinical setting. A simple sampling technique to recover viable bacteria &om disinfected endoscopes was introduced. This has been routinely applied on a monthly basis over a 3-year period in a Gastroenterology Depamnent which performs over 2,500 endoscopies a year. Despite the diligent application of comprehensive cleaning and disinfection protocols, bacteriological monitoring detected rectifiable failures in disinfection that would otherwise have gone unrecognised.
Aeromonas suecies are water organisms that may cause gastroenteritis and septicaemia, particularly in the immuncucompromised. They have been less frequently described as a cause of wound infection. We report 6 cases of severe wound infection with these organisms which were associated with major trauma and water. In our experience, such infections are more likely to occur in young males d u n n g rhe summer months. The severity of infection was determined primarily by the extent of the underlying injury and in h s setting, Aeromonas SDD. may be isolated as a component of apolymicrobial infection. Antimicrobial treatment u1 the absence of adequate surgical debridenlent was often unsuccessful. When treating trauma associated with water, the anthicrohial regimen used should include cover for Aeromonas SUD.
Presenter: Dr. John H. Andrew, Microbiology Department, SVH.
Presenter: Dr. Richard Bunter, Microbiology Department, SVH.