Limits...
Isolation and Host Range of Bacteriophage with Lytic Activity against Methicillin-Resistant Staphylococcus aureus and Potential Use as a Fomite Decontaminant.

Jensen KC, Hair BB, Wienclaw TM, Murdock MH, Hatch JB, Trent AT, White TD, Haskell KJ, Berges BK - PLoS ONE (2015)

Bottom Line: Phage therapy entails the use of phage to treat or prevent bacterial infections.Primary SA strains were also isolated from environmental sources to be used as tools for phage discovery and isolation as well as to examine the target cell host range of the phage isolates by spot testing.Experiments were performed to assess the host range and killing potential of newly discovered phage, and significant reductions in bacterial load were detected.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Molecular Biology, Brigham Young University, Provo, Utah, 84602, United States of America.

ABSTRACT
Staphylococcus aureus (SA) is a commensal bacterium and opportunistic pathogen commonly associated with humans and is capable of causing serious disease and death including sepsis, pneumonia, and meningitis. Methicillin-resistant SA (MRSA) isolates are typically resistant to many available antibiotics with the common exception of vancomycin. The presence of vancomycin resistance in some SA isolates combined with the current heavy use of vancomycin to treat MRSA infections indicates that MRSA may achieve broad resistance to vancomycin in the near future. New MRSA treatments are clearly needed. Bacteriophages (phages) are viruses that infect bacteria, commonly resulting in death of the host bacterial cell. Phage therapy entails the use of phage to treat or prevent bacterial infections. In this study, 12 phages were isolated that can replicate in human SA and/or MRSA isolates as a potential way to control these infections. 5 phage were discovered through mitomycin C induction of prophage and 7 others as extracellular viruses. Primary SA strains were also isolated from environmental sources to be used as tools for phage discovery and isolation as well as to examine the target cell host range of the phage isolates by spot testing. Primary isolates were tested for susceptibility to oxacillin in order to determine which were MRSA. Experiments were performed to assess the host range and killing potential of newly discovered phage, and significant reductions in bacterial load were detected. We explored the utility of some phage to decontaminate fomites (glass and cloth) and found a significant reduction in colony forming units of MRSA following phage treatment, including tests of a phage cocktail against a cocktail of MRSA isolates. Our findings suggest that phage treatment can be used as an effective tool to decontaminate human MRSA from both hard surfaces and fabrics.

No MeSH data available.


Related in: MedlinePlus

Assessment of host range by lysis of bacterial cultures.Phage were added to log phase bacterial cultures to assess host range and to determine the killing efficiency of the phages. Optical density was measured at 600nm to quantify cell density of the culture. A) MRSA strain DH1 infected with phage strain SEW across a time course. B) MRSA strain DH1 infected with phage strain CJ11 across a time course. C) A variety of bacterial strains were challenged with different phage and OD600 readings were taken at 4h. Results are reported in ΔOD600 units which were calculated as the difference between the OD600 of mock-treated cultures (sterile phage buffer only) and phage-treated cultures. D) Various combinations of bacterial strains were treated with either single phage strains or combinations phage. In panels C and D, the percent difference in OD600 readings (phage-treated divided by mock-treated) is also shown. All experiments were performed in triplicate; standard error is indicated. * p ≤ 0.002 by student’s t test. # p ≤ 0.01 by student’s t test when evaluating phage treated vs mock treated samples.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4488860&req=5

pone.0131714.g001: Assessment of host range by lysis of bacterial cultures.Phage were added to log phase bacterial cultures to assess host range and to determine the killing efficiency of the phages. Optical density was measured at 600nm to quantify cell density of the culture. A) MRSA strain DH1 infected with phage strain SEW across a time course. B) MRSA strain DH1 infected with phage strain CJ11 across a time course. C) A variety of bacterial strains were challenged with different phage and OD600 readings were taken at 4h. Results are reported in ΔOD600 units which were calculated as the difference between the OD600 of mock-treated cultures (sterile phage buffer only) and phage-treated cultures. D) Various combinations of bacterial strains were treated with either single phage strains or combinations phage. In panels C and D, the percent difference in OD600 readings (phage-treated divided by mock-treated) is also shown. All experiments were performed in triplicate; standard error is indicated. * p ≤ 0.002 by student’s t test. # p ≤ 0.01 by student’s t test when evaluating phage treated vs mock treated samples.

Mentions: Unpaired, one-tailed student’s t tests were performed in experiments from Figs 1, 2, and 3 in order to determine if significant differences existed between phage-treated and mock-treated samples. A value of p ≤ 0.05 was considered to be statistically significant.


Isolation and Host Range of Bacteriophage with Lytic Activity against Methicillin-Resistant Staphylococcus aureus and Potential Use as a Fomite Decontaminant.

Jensen KC, Hair BB, Wienclaw TM, Murdock MH, Hatch JB, Trent AT, White TD, Haskell KJ, Berges BK - PLoS ONE (2015)

Assessment of host range by lysis of bacterial cultures.Phage were added to log phase bacterial cultures to assess host range and to determine the killing efficiency of the phages. Optical density was measured at 600nm to quantify cell density of the culture. A) MRSA strain DH1 infected with phage strain SEW across a time course. B) MRSA strain DH1 infected with phage strain CJ11 across a time course. C) A variety of bacterial strains were challenged with different phage and OD600 readings were taken at 4h. Results are reported in ΔOD600 units which were calculated as the difference between the OD600 of mock-treated cultures (sterile phage buffer only) and phage-treated cultures. D) Various combinations of bacterial strains were treated with either single phage strains or combinations phage. In panels C and D, the percent difference in OD600 readings (phage-treated divided by mock-treated) is also shown. All experiments were performed in triplicate; standard error is indicated. * p ≤ 0.002 by student’s t test. # p ≤ 0.01 by student’s t test when evaluating phage treated vs mock treated samples.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4488860&req=5

pone.0131714.g001: Assessment of host range by lysis of bacterial cultures.Phage were added to log phase bacterial cultures to assess host range and to determine the killing efficiency of the phages. Optical density was measured at 600nm to quantify cell density of the culture. A) MRSA strain DH1 infected with phage strain SEW across a time course. B) MRSA strain DH1 infected with phage strain CJ11 across a time course. C) A variety of bacterial strains were challenged with different phage and OD600 readings were taken at 4h. Results are reported in ΔOD600 units which were calculated as the difference between the OD600 of mock-treated cultures (sterile phage buffer only) and phage-treated cultures. D) Various combinations of bacterial strains were treated with either single phage strains or combinations phage. In panels C and D, the percent difference in OD600 readings (phage-treated divided by mock-treated) is also shown. All experiments were performed in triplicate; standard error is indicated. * p ≤ 0.002 by student’s t test. # p ≤ 0.01 by student’s t test when evaluating phage treated vs mock treated samples.
Mentions: Unpaired, one-tailed student’s t tests were performed in experiments from Figs 1, 2, and 3 in order to determine if significant differences existed between phage-treated and mock-treated samples. A value of p ≤ 0.05 was considered to be statistically significant.

Bottom Line: Phage therapy entails the use of phage to treat or prevent bacterial infections.Primary SA strains were also isolated from environmental sources to be used as tools for phage discovery and isolation as well as to examine the target cell host range of the phage isolates by spot testing.Experiments were performed to assess the host range and killing potential of newly discovered phage, and significant reductions in bacterial load were detected.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Molecular Biology, Brigham Young University, Provo, Utah, 84602, United States of America.

ABSTRACT
Staphylococcus aureus (SA) is a commensal bacterium and opportunistic pathogen commonly associated with humans and is capable of causing serious disease and death including sepsis, pneumonia, and meningitis. Methicillin-resistant SA (MRSA) isolates are typically resistant to many available antibiotics with the common exception of vancomycin. The presence of vancomycin resistance in some SA isolates combined with the current heavy use of vancomycin to treat MRSA infections indicates that MRSA may achieve broad resistance to vancomycin in the near future. New MRSA treatments are clearly needed. Bacteriophages (phages) are viruses that infect bacteria, commonly resulting in death of the host bacterial cell. Phage therapy entails the use of phage to treat or prevent bacterial infections. In this study, 12 phages were isolated that can replicate in human SA and/or MRSA isolates as a potential way to control these infections. 5 phage were discovered through mitomycin C induction of prophage and 7 others as extracellular viruses. Primary SA strains were also isolated from environmental sources to be used as tools for phage discovery and isolation as well as to examine the target cell host range of the phage isolates by spot testing. Primary isolates were tested for susceptibility to oxacillin in order to determine which were MRSA. Experiments were performed to assess the host range and killing potential of newly discovered phage, and significant reductions in bacterial load were detected. We explored the utility of some phage to decontaminate fomites (glass and cloth) and found a significant reduction in colony forming units of MRSA following phage treatment, including tests of a phage cocktail against a cocktail of MRSA isolates. Our findings suggest that phage treatment can be used as an effective tool to decontaminate human MRSA from both hard surfaces and fabrics.

No MeSH data available.


Related in: MedlinePlus