Survival of Bacteria on Respirator Filters

The survival and potential growth of two different kinds of bacteria were investigated on NIOSH-certified polypropylene respirator filters. Bacillus subtilis var niger (B. subtilis) spores represented environmentally resistant bacteria, whereas Pseudomonas fluorescens (P. fluorescens) vegetative cells represented stress-sensitive bacteria. The bacteria were aerosolized and loaded on the respirator filters under three nutritional conditions: water, saliva, and tryptic soy broth (TSB). The loaded filters were incubated for 0-13 days and analyzed for culturable and total bacteria count. The analysis was optimized through the evaluation of three methods for eluting bacteria from respirator filter samples: low frequency shaking, vortexing, and ultrasonic vibrating. Vortexing was found to be the most effective with the highest total and culturable count and was therefore used for the analysis of bacterial survival and growth. Neither of the test bacteria was able to grow on the respirator filters even under opt...

[1]  T. Reponen,et al.  Survival of Mycobacteria on N95 Personal Respirators , 1999, Infection Control & Hospital Epidemiology.

[2]  J. Vincent,et al.  Improved methods for generation, sampling, and recovery of biological aerosols in filter challenge tests. , 1998, American Industrial Hygiene Association journal.

[3]  C C Coffey,et al.  Performance of N95 respirators: filtration efficiency for airborne microbial and inert particles. , 1998, American Industrial Hygiene Association journal.

[4]  K Willeke,et al.  Performance of N95 respirators: reaerosolization of bacteria and solid particles. , 1997, American Industrial Hygiene Association journal.

[5]  K. Willeke,et al.  Particle Reentrainment from Fibrous Filters , 1997 .

[6]  R. Maus,et al.  Viability of bacteria in unused air filter media , 1997 .

[7]  E. Karg,et al.  Estimation of the size distribution of aerosols produced by jet nebulizers as a function of time , 1997 .

[8]  K. Fennelly.  Personal respiratory protection against Mycobacterium tuberculosis. , 1997, Clinics in chest medicine.

[9]  E. McCray,et al.  Hospital infection control practices for tuberculosis. , 1997, Clinics in chest medicine.

[10]  J. Dutkiewicz,et al.  Bioaerosols and occupational lung disease , 1994 .

[11]  I. Resnick,et al.  Efficacy of Selected Respiratory Protective Equipment Challenged with Bacillus subtilis subsp. niger , 1994, Applied and environmental microbiology.

[12]  J. Ruuskanen,et al.  Microbial growth on respirator filters from improper storage. , 1993, Scandinavian journal of work, environment & health.

[13]  R. Loudon,et al.  Droplet expulsion from the respiratory tract. , 1967, The American review of respiratory disease.

[14]  K. Willeke,et al.  Aerosolization of Particles from a Bubbling Liquid: Characteristics and Generator Development , 1997 .

[15]  B. Crook,et al.  Fungal and actinomycete spores as pollutants of the workplace and occupational allergens. , 1988, The Annals of occupational hygiene.