Microbiological Aspects of Decontamination - Essay Example

INTRODUCTION Neurological prostheses commonly manufactured are shunts for the central nervous system of patients with hydrocephalus, Ommaya reservoirs, intracranial pressure devices, and implantable neurological stimulators (von Eiff, et al., 2005, p.181). These are susceptible to bacterial and fungal contamination. In their production where much of the activity is in clean room environments, extremophilic (requiring extreme conditions for viability) and extremotolerant (can withstand worst conditions) pathogenic bacteria can still exist (La Duc, et al., 2007, pp. 2600, 2603). Although not recorded by La Duc et al. (2007, p. 2600) as a common member of clean room microflora, Staphylococci can pose serious health risks to patients, and must be looked out for when determining clean room biocontamination. They are the main pathogenic microorganisms in medical device-related infections. Much of their success is caused by their strong surface adhesion and biofilm formation. Biofilms are especially important because they impose resistance against host defence and antibiotics (von Eiff, et al., 2005, pp. 182). If clean room conditions are suddenly compromised, the sterility of devices prepared in it will be compromised as well. Once the contaminants grow significantly large in the body, localized inflammation, sepsis, or even death can occur (von Eiff, et al., 2005, pp. 183). And because antibiotics do not seem to work, removal of prostheses thus becomes inevitable (von Eiff, et al., 2005, p. 186). It is thus imperative that possibilities for contamination in clean room environments for neurological prostheses production are kept to a minimum. This review looked at rooms for improvement on the current procedures used by The Future Technology Company in ensuring pathogen-free production area for active implantable neurological prostheses manufacture. However, this review was limited to suggesting improvements on the current biocontamination control and sampling methods done in the newly-prepared clean room of the company. However, this review did not suggest improvements that will entail reconstruction of the clean room, as it might pose significant financial pressure onto the company. Nonetheless, reconstruction is not discouraged, and its implementation is at the consent of the company. EVALUATION OF BIOCONTAMINATION CONTROL 1. MATERIALS AND EQUIPMENT The company was successful in preparing a formal system of biocontamination control. They established a limit to the microbes in the room by (1) using laminar airflow (LAF) cabinets, (2) changing room, and (3) positive air pressure provider. However, it could have been better if the report also included the contamination control concept for each unit. In addition, the reason/s behind their positions in the clean room should have been enumerated. Optimal clean room layout can minimize risks for product biocontamination. (ISO 14644-4: 2001, pp. 4-5). The positioning of equipment and the designation of work areas should be planned in a way to minimize turbulent airflow (ISO 14644-4: 2001, p. 12). As such, the airflow should have been described more extensively. In the study, it was not explicitly mentioned whether the airflow is unidirectional, non-unidirectional, or mixed. If non-unidirectional, the position of filter outlets and inlets should have been carefully spaced out within the clean room, so that dead zones are avoided. If mixed, a vertical supply flow should have been utilized, because all work are done on horizontal surfaces. Also, priority processes such as sterilization of prostheses should be held adjacent to the clean air supply, because working away from these positions might cause contamination from particles upstream. For this reason that the change room should have been positioned downstream of clean processing (ISO 14644-4: 2001, p. 10). . The study should have had the following guidelines for the use of change room: (1) a limit on the number of people in the change room at any given time, (2) gowning procedure, and (3) frequency of gowning replacement. Aside from handwash basin and lockers, the company could also add storage and disposal area of garments and consumable items (i.e., gloves, masks, etc.), and full-length mirrors to check proper laboratory attire (ISO 14644-4: 2001, p. 26). In addition, clean room clothing should be cleaned, processed, packaged, and used under set guidelines (ISO 14644-5: 2004, p. 4). The number of materials, equipment, and supplies inside the clean room should be kept at a minimum (ISO 14644-5: 2004, p. 5). Their maintenance and cleanliness should also be prioritized and be well-documented (ISO 14644-2: 2001, p. 7). A cleaning programme should be carefully laid out. Usually, cleaning of surfaces should be done at least once a week (ISO 14644-5: 2004, p. 36). 2. TARGET, ALERT, AND ACTION LEVELS Action levels were set by the company at these arbitrary conditions, until continued monitoring allows them to predict a trend (p. 16 of validation report). However, target and alert levels were not identified. Alert levels are important because they give a chance for the company to intervene against a potentially hazardous situation. It will allow the company to avoid conditions in which the prostheses out in the market are unsterile. On the other hand, target levels define the lowest amount of microbes that the system can allow. Once microbe levels go past the target levels, it gives a signal for the company to look for possible cracks in the system. The company should define their own target and alert levels, and these should be based on the capacity of their biocontamination control system and the level of microbes the clean room should have in order to prevent the prostheses from being contaminated (ISO 14698-1: 2003, p. 5). 3. SAMPLING METHODS 3. 1. Clean room state during sampling Sampling was performed as-built, as indicated implied in the 5th page of the validation report, It was presumed by the company and the tester that at this point the amount of microorganisms in the clean room is at its highest. Probably, they were accounting for the fact that the positive air pressure was not yet maintained, and the microbes in the room were not yet forced out of the clean room. However, they failed to account the possible added microbes that can come from personnel activity inside the room. In accordance to ISO 14698-1: 2003 (p. 7), it is thus suggested by this critical review that sampling be done at operational occupancy state. 3. 2. Mode of sampling and sampling sites The validation study succeeded in sampling from all possible risk zones: air, surfaces, and water (ISO 14698-1: 2003, p. 5). To determine the presence of fungal and bacterial airborne contaminants, Dr. Rod Coliform used settle plates. However, the sampling was not complete. According to ISO 14698-1: 2003 (p. 13), for settle plates to be a quantitative assessment of airborne microbes, a time-coursed sampling should have been done to calculate airborne microbes. 3. 3. Frequency of sampling The frequency of sampling was not defined by the report, but the company should follow ISO 14698-1: 2003 (pp. 7-8). Sampling should be done (1) when microbe levels went beyond action or alert levels consecutively, (2) when clean room operation was shut down for a long time, (3) when pathogens were detected in risk zones, (4) when maintenance work was performed on the system, (5) unsterile prostheses, (6) when procedures are changed, and (7) when incidents suspected of contamination happen. 3.4. Sample identification In the sampling done in the clean room as-built, the isolates were not identified. This review suggests that the isolates be identified and be documented. It helps in determining the right cleaning and disinfecting procedures that can be done in the clean room (ISO 14698-1: 2003, p. 10). For example, contamination with spore-formers such as fungi and some other bacteria may be resistant to 70% ethanol sterilization. As such, this disinfection technique will be ineffective against that specific contamination. In addition, it may help in identifying the source of contamination. For example, if a Staphylococcus was sampled from both the surface and the laboratory attire used by the person working there, then the cause of contamination can be isolated to the gown. Because the source was isolated, appropriate, specific actions can be imposed to avoid future contaminations of the same nature. 3. Data documentation AND REVIEW Data should be well-documented. It gives the company an audit trail to allow comparison between sampling periods (ISO 14698-2: 2003, p. 1). It is for samplers to point at possible reasons why data changed from one sampling period to another. For proper documentation, among those that need to be recorded are ocular observations, calculations, derived data, samplers, and modes of preparation, testing, and evaluation (ISO 14698-2: 2003, p. 4). This is especially important for medical device manufacturers since documentations must be readily available for the customer for at least the lifetime of the medical device, but not less than two years after the product has been released (ISO 13485: 2003, p. 6). At planned intervals, the documents shall be reviewed. Discussion includes analysis of data between samplings, changes on the biocontamination control system, recommendations for improvement of the procedure, and new or revised regulatory requirements, and provide for resources needed to employ these changes (ISO 13485: 2003, p. 8). However, as of the time of sampling, monitoring and observing schedule were not yet mentioned, corrective measures upon alert and action levels were not yet thought of, and organization of test results were not yet planned (ISO 14698-1: 2003, p. 4). These should be addresses as soon as possible. 5. PERSONNEL The company had indicated in their report that the personnel were undergoing training during the time of sampling. However, the techniques taught in the training should have also been indicated. The topics during the training should range from microbiology principles, to laboratory methods and writing clear reports. The company should also define the specific responsibilities of the personnel assigned in the clean room. A person must be assigned to oversee the biocontamination control system, including making the company aware of regulatory and customer requirements, employing and analyzing the results of sampling, and reporting to the company necessary adjustments to the sampling procedures. In addition, an interrelation among personnel should be demanded by the company (ISO 13485: 2003, p. 7). REFERENCES ISO 13485: 2003, Medical devices – quality management systems – requirements for requlatory purposes, International Organization for Standardization, Brussels. ISO 14644-4: 2001, Cleanrooms and associated controlled environments – biocontamination control – part 4: design, construction and start-up, International Organization for Standardization, Brussels. ISO 14644-5: 2004, Cleanrooms and associated controlled environments – biocontamination control – part 5: operations, International Organization for Standardization, Brussels. ISO 14698-1: 2003, Cleanrooms and associated controlled environments – biocontamination control – part 1: general principles and methods, International Organization for Standardization, Brussels. ISO 14698-2: 2003, Cleanrooms and associated controlled environments – biocontamination control – part 2: evaluation and interpretation of biocontamination data, International Organization for Standardization, Brussels. La Duc, MT, Dekas, A, Osman, S, Moissl,S, Newcombe, D, & Venkateswaran, K 2007, ‘Isolation and characterization of bacteria capable of tolerating the extreme conditions of clean room environments,’ Applied and Environmental Microbiology, vol. 73, no. 8, pp. 2600-2611. von Eiff, C, Jansen, B, Kohnen, W, & Becker, K 2005, ‘Infections associated with medical devices,’ Drugs, vol. 65, no. 2, pp. 179-214. Read More