Antibacterial Activity Assessment of Medical Gloves
ASTM D7907-14 – Determination of Bactericidal Efficacy on the Surface of Medical Examination Gloves
ASTM D7907-14 is a standard test method used to determine the bactericidal efficacy of gloves used for medical examination.
In patient care settings, the hands of healthcare providers and workers are continuously exposed to skin wounds, contaminated surgical equipment, and other inanimate surfaces that serve as a potential risk for infection spread. Hence, wearing gloves is considered a primary preventive measure to avoid transmission of infection within patients and outside places as well. As per evidence, using non-sterile gloves can also pose the risk of microbial contamination, resulting in both nosocomial and community-acquired infections.
The good news is, medical gloves comprising bactericidal properties are capable of providing protection against bacterial infections. Both the inside and outside surfaces of such medical gloves are integrated with the bactericidal agents, which in turn kill or inhibit the growth of pathogenic bacteria.
The aim of ASTM D7907-14 test method is to ensure the bactericidal activity of treated medical gloves against a range of pathogenic microorganisms, ubiquitous in hospital environments.
ASTM D7907-14 Test Conditions
Interfering substances – For ASTM D7907-14 test, it is important to select the interfering substances that can stimulate contamination and also impact the bactericidal activity of treated samples in actual conditions. Organic (microbial) load common in a hospital environment is selected as an interfering substance to check the antibacterial efficacy.
Test bacteria – Test bacteria are selected depending upon the intended use and exposure of treated gloves under specific conditions.
Contact time – In this test, four exposure periods (0, 5, 10, 20, and 30 min) are mandatory to know if the treated product is effective against microbes.
ASTM D7907-14 Test Methods
ASTM D7907-14 specifies two test methods for quantitative analysis of the bactericidal activity on the surfaces ( inside or outside) of test materials.
- Method A
- The bacterial suspension with the titre of 108 CFU/mL is prepared in a sterile standard or phosphate-buffered saline without any interfering substance (organic load).
- 20 ul of bacterial suspension is evenly spread over the test (treated) and control (untreated) samples and covered by a coverslip. The bacterial suspension must contain a minimum titer of 106 test bacteria to ensure that there is enough number of viable cells and to be calculated for at least for 4 log reduction.
- Both control and test samples are allowed to complete the specified contact times (as per standard guidelines or suggested by the manufacturer).
- Immediately after contact periods, test and control samples without removing the coverslips are transferred into a sterile centrifuge tube containing 10 ml of neutralizing solution. And mixed for 15 seconds using a vortex mixer.
- 0.05 mL aliquot from the neutralization extraction tube is taken and plated on a growth medium.
- After the incubation period of 24 hours – 48 hours, bactericidal activity is determined by the enumeration of bacteria on both test and control samples.
- Method B
- 108 CFU/mL bacterial suspension is prepared in a sterile standard or phosphate-buffered saline along with an interfering substance (organic load).
- Both the test (treated) and control (untreated) samples are exposed to the organic load prior to bacterial inoculation.
- 20 ul of bacterial suspension is evenly spread over the test (treated) and control (untreated) samples and covered by a coverslip. The bacterial suspension must contain a minimum titer of 106 test bacteria to ensure that there is enough number of viable cells and to be calculated at least for 4 log reduction.
- Similar to method A, all the next steps are followed for the contact period, neutralization, and enumeration of bacteria in both test and control samples.
At Microbe Investigations, we offer a comprehensive suite of microbiology testing services. We ensure to establish all steps of testing analysis with all the precision such as sample collection, sample preparation, analysis, test reporting, and interpretation. Our aim is to deliver rapid and high-quality results for testing materials.
Contact us today for a quote on ASTM D7907-14 and more information on our microbiology testing services.
ASTM D7907 is a standard test method for measuring the bactericidal activity of medical gloves. ASTM D7907 specifies two analytical methods for evaluating the surface bactericidal activity of surfaces of gloves used in hospital environments.
ASTM D7907 test is applicable for gloves intended to be used in health care settings.
ASTM D7907 test takes 3-4 days to complete.
At Microbe Investigations, we understand the need for accuracy and speed. We test for ASTM D7907 using the following bacteria: Pseudomonas aeruginosa (ATCC 15442), Escherichia coli (ATCC 8739), Staphylococcus aureus (ATCC 6538P), Enterococcus hirae (ATCC 10541), Klebsiella pneumoniae (ATCC 4352), MRSA (ATCC 33591), Salmonella enterica ( ATCC 10708), Candida Albicans (MTCC 3017). Additional strains can be added on request.