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Aerial dissemination of Clostridium difficile spores.

Roberts K, Smith CF, Snelling AM, Kerr KG, Banfield KR, Sleigh PA, Beggs CB - BMC Infect. Dis. (2008)

Bottom Line: Environmental contamination is known to play an important contributory role in the spread of CDAD and it is suspected that contamination might be occurring as a result of aerial dissemination of C. difficile spores.However previous studies have failed to isolate C. difficile from air in hospitals.Although preliminary, the findings reinforce concerns that current C. difficile control measures may be inadequate and suggest that improved ward ventilation may help to reduce the spread of CDAD in healthcare facilities.

View Article: PubMed Central - HTML - PubMed

Affiliation: Pathogen Control Engineering Research Group, School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK. ka_roberts2003@yahoo.co.uk

ABSTRACT

Background: Clostridium difficile-associated diarrhoea (CDAD) is a frequently occurring healthcare-associated infection, which is responsible for significant morbidity and mortality amongst elderly patients in healthcare facilities. Environmental contamination is known to play an important contributory role in the spread of CDAD and it is suspected that contamination might be occurring as a result of aerial dissemination of C. difficile spores. However previous studies have failed to isolate C. difficile from air in hospitals. In an attempt to clarify this issue we undertook a short controlled pilot study in an elderly care ward with the aim of culturing C. difficile from the air.

Methods: In a survey undertaken during February (two days) 2006 and March (two days) 2007, air samples were collected using a portable cyclone sampler and surface samples collected using contact plates in a UK hospital. Sampling took place in a six bedded elderly care bay (Study) during February 2006 and in March 2007 both the study bay and a four bedded orthopaedic bay (Control). Particulate material from the air was collected in Ringer's solution, alcohol shocked and plated out in triplicate onto Brazier's CCEY agar without egg yolk, but supplemented with 5 mg/L of lysozyme. After incubation, the identity of isolates was confirmed by standard techniques. Ribotyping and REP-PCR fingerprinting were used to further characterise isolates.

Results: On both days in February 2006, C. difficile was cultured from the air with 23 samples yielding the bacterium (mean counts 53 - 426 cfu/m3 of air). One representative isolate from each of these was characterized further. Of the 23 isolates, 22 were ribotype 001 and were indistinguishable on REP-PCR typing. C. difficile was not cultured from the air or surfaces of either hospital bay during the two days in March 2007.

Conclusion: This pilot study produced clear evidence of sporadic aerial dissemination of spores of a clone of C. difficile, a finding which may help to explain why CDAD is so persistent within hospitals and difficult to eradicate. Although preliminary, the findings reinforce concerns that current C. difficile control measures may be inadequate and suggest that improved ward ventilation may help to reduce the spread of CDAD in healthcare facilities.

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PCR ribotype profiles of C. difficile isolates CAS 1 to 10 (lanes 1–10) obtained from air samples, Lane R = ribotype 001 reference strain. Lane M = O'GeneRuler™ DNA ladder (10 kbp – 100 bp).
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Figure 4: PCR ribotype profiles of C. difficile isolates CAS 1 to 10 (lanes 1–10) obtained from air samples, Lane R = ribotype 001 reference strain. Lane M = O'GeneRuler™ DNA ladder (10 kbp – 100 bp).

Mentions: It should be noted that no sample was collected at 09.45 on day 1. Twenty-three air samples in total yielded C. difficile andone representative isolate (coded CAS 1 to 23) from each of these was ribotyped. Of the 23 isolates, 22 belonged to ribotype 001 (Figure 4). All of these had the same REP-PCR profile, but the pattern was different to that of the ribotype 001 reference strain (data not shown). The ribotype of the remaining isolate did not match any of the reference strains.


Aerial dissemination of Clostridium difficile spores.

Roberts K, Smith CF, Snelling AM, Kerr KG, Banfield KR, Sleigh PA, Beggs CB - BMC Infect. Dis. (2008)

PCR ribotype profiles of C. difficile isolates CAS 1 to 10 (lanes 1–10) obtained from air samples, Lane R = ribotype 001 reference strain. Lane M = O'GeneRuler™ DNA ladder (10 kbp – 100 bp).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2245947&req=5

Figure 4: PCR ribotype profiles of C. difficile isolates CAS 1 to 10 (lanes 1–10) obtained from air samples, Lane R = ribotype 001 reference strain. Lane M = O'GeneRuler™ DNA ladder (10 kbp – 100 bp).
Mentions: It should be noted that no sample was collected at 09.45 on day 1. Twenty-three air samples in total yielded C. difficile andone representative isolate (coded CAS 1 to 23) from each of these was ribotyped. Of the 23 isolates, 22 belonged to ribotype 001 (Figure 4). All of these had the same REP-PCR profile, but the pattern was different to that of the ribotype 001 reference strain (data not shown). The ribotype of the remaining isolate did not match any of the reference strains.

Bottom Line: Environmental contamination is known to play an important contributory role in the spread of CDAD and it is suspected that contamination might be occurring as a result of aerial dissemination of C. difficile spores.However previous studies have failed to isolate C. difficile from air in hospitals.Although preliminary, the findings reinforce concerns that current C. difficile control measures may be inadequate and suggest that improved ward ventilation may help to reduce the spread of CDAD in healthcare facilities.

View Article: PubMed Central - HTML - PubMed

Affiliation: Pathogen Control Engineering Research Group, School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK. ka_roberts2003@yahoo.co.uk

ABSTRACT

Background: Clostridium difficile-associated diarrhoea (CDAD) is a frequently occurring healthcare-associated infection, which is responsible for significant morbidity and mortality amongst elderly patients in healthcare facilities. Environmental contamination is known to play an important contributory role in the spread of CDAD and it is suspected that contamination might be occurring as a result of aerial dissemination of C. difficile spores. However previous studies have failed to isolate C. difficile from air in hospitals. In an attempt to clarify this issue we undertook a short controlled pilot study in an elderly care ward with the aim of culturing C. difficile from the air.

Methods: In a survey undertaken during February (two days) 2006 and March (two days) 2007, air samples were collected using a portable cyclone sampler and surface samples collected using contact plates in a UK hospital. Sampling took place in a six bedded elderly care bay (Study) during February 2006 and in March 2007 both the study bay and a four bedded orthopaedic bay (Control). Particulate material from the air was collected in Ringer's solution, alcohol shocked and plated out in triplicate onto Brazier's CCEY agar without egg yolk, but supplemented with 5 mg/L of lysozyme. After incubation, the identity of isolates was confirmed by standard techniques. Ribotyping and REP-PCR fingerprinting were used to further characterise isolates.

Results: On both days in February 2006, C. difficile was cultured from the air with 23 samples yielding the bacterium (mean counts 53 - 426 cfu/m3 of air). One representative isolate from each of these was characterized further. Of the 23 isolates, 22 were ribotype 001 and were indistinguishable on REP-PCR typing. C. difficile was not cultured from the air or surfaces of either hospital bay during the two days in March 2007.

Conclusion: This pilot study produced clear evidence of sporadic aerial dissemination of spores of a clone of C. difficile, a finding which may help to explain why CDAD is so persistent within hospitals and difficult to eradicate. Although preliminary, the findings reinforce concerns that current C. difficile control measures may be inadequate and suggest that improved ward ventilation may help to reduce the spread of CDAD in healthcare facilities.

Show MeSH
Related in: MedlinePlus