RECENT UPDATES

Microbiotest's Donna Suchmann to chair AOAC symposium on Disinfectants, Steve Zhou to present Viral Clearance 09/26-to 09/29 in Orlando FL.

MicroBioTest Division's Donna Suchmann to chair AOAC symposium on Disinfectants, Steve Zhou to present Viral Clearance Paper at AOAC International's annual meeting 09/26-to 09/29 in Orlando FL.

Virucidal Efficacy Testing against Avian Influenza H5N1 now available at MICROBIOTEST

MICROBIOTEST is excited to announce the launch of virucidal effectiveness testing against avian influenza virus H5N1.

Although avian influenza viruses have a broad host range in general, it is rare for an individual strain or subtype to infect more than one species. Until just a few years ago, the occasional infection of humans by avian influenza virus was considered low risk and non human-to-human transmissible. This perception, however, was fundamentally changed with the emergence of the highly pathogenic avian influenza (HPAI) virus. The HPAI virus, carrying genetic mutations in the haemagglutinin (HA) surface protein, is much more virulent and has infected an unusual variety of host species including humans across the world. Since 1997, the HPAI outbreaks have led to the deaths of millions of poultry and more than ten thousands of wild birds, and more than 300 human infections with a mortality rate of around 63% (1). The lethality of human infection triggered the World Health Organization (WHO) to declare a pandemic alert in February 2003.

The global spread of this disease has also provided more opportunities for viral re-assortment and mutation, leading to an increased risk of trans-species and even human-to-human transmission. For example, viral samples recently isolated from a fatal human case of HPAI revealed a change in the receptor binding preference of HA from avian- to human-type receptor, confirming the existence of an HPAI strain that has specificity for humans (2). Thus, the pandemic influenza threat presented by HPAI viruses remains severe.

As adequate amounts of vaccine or anti-viral agents are unlikely to be available early on in a pandemic, non-pharmaceutical interventions such as public hygiene and disinfection for preparedness planning efforts are critical. To date, most of the disinfectant evaluation studies targeting avian influenza viruses have used the low pathogenic subtypes such as H9N2 (“H” for haemagglutinin and “N” for neuraminidase), however, the predominant subtype of HPAI is H5N1. It is yet unclear if differences exist in strain susceptibility to a specific disinfectant or hand hygiene product.

MICROBIOTEST has recently acquired an HPAI H5N1 strain (NIBRG-14). We have established a robust tissue culture infectivity assay to measure the titer of the virus and have successfully conducted several virucidal efficacy tests. We believe that testing the avian influenza H5N1, rather than other low pathogenic strains, would provide more accurate determination of the efficacy of a disinfection or hand hygiene program.

If you have any questions or need further information, please do not hesitate to contact us at 703-925-0100 or services@microbiotest.com.

REFERENCES:

1. World Health Organization. Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H5N1) Reported to WHO. 28 May 2008.
2. Auewarakul P, Suptawiwat O, Kongchanagul A, Sangma C, Suzuki Y, Ungchusak K, et. al. 2007. An avian influenza H5N1 virus that binds to a human-type receptor. J. Virol. 81(18):9950-9955.

Virucidal Efficacy Testing against Murine Norovirus (MNV) Now Available at MICROBIOTEST

Human norovirus (HNV) causes greater than 90% of nonbacterial, epidemic gastroenteritis worldwide. In the United States alone, HNV causes approximately 23 million cases of gastroenteritis and 50,000 hospitalizations per year (1, 2). Most disease outbreaks occur in crowded locations such as cruise ships, schools, hospitals, hotels, aircraft carriers, nursing homes and restaurants. Due to the significant economic impact and morbidity caused by HNV and absence of an effective therapy, environmental disinfection is critical in controlling norovirus infection.

Studies on the stability and inactivation of HNV have been hampered by the lack of a cell culture system. To date, studies to evaluate the virucidal effectiveness of a treatment against HNV were usually performed using a cultivable surrogate virus, such as feline calicivirus (FCV).

The discovery of murine norovirus (MNV) by investigators at Washington University in 2003 (3), however, provides the potential for a new, and possibly more appropriate, surrogate for HNV. Several studies have confirmed this. Like HNV, MNV belongs to the Norovirus genus of the Caliciviridae family of viruses and it is the first norovirus to be propagated in cell culture (4). Comparing to FCV, MNV is genetically closer to HNV since FCV belongs to a different genus, Vesivirus. (4). FCV is a respiratory agent whereas both HNV and MNV are enteric pathogens (4). FCV is not stable under acidic pH whereas MNV and presumably HNV since it is an enteric pathogen, are stable at gastric pH levels (5, 6). The reduction in FCV infectivity is significantly faster than reductions of several other enteric viruses including MNV (7). Recently issued Centers for Disease Control and Prevention (CDC) “Norovirus in Healthcare Facilities Fact Sheet” cautioned that there is debate on how well data on inactivation of FCV reflects efficacy against HNV (8).

In addition to serving as a surrogate for HNV, MNV is an infectious agent of high concern in murine industry as it is one of the most common viral agents among laboratory mice and rats (3). Disinfectant efficacy testing against MNV is therefore directly relevant to the biomedical research field.

MICROBIOTEST has recently launched the Virucidal Efficacy Testing against murine norovirus. We have successfully executed several virucidal effectiveness tests using this virus. We believe that testing against MNV, in addition to FCV, is critical in assuring the efficacy of a disinfectant product against human norovirus.

If you have any questions or need further information, please do not hesitate to contact us at 703-925-0100 or services@microbiotest.com.



REFERENCES:

1. Hutson AM, Atmar RL, Estes MK. 2004. Norovirus disease: changing epidemiology and host susceptibility factors. Trends Microbiol. Jun;12(6):279-87.
2. Mead PS, Slutsker L, Dietz V, McCaig LF, Bresee JS, Shapiro C, Griffin PM, Tauxe RV. 1999. Food-related illness and death in the United States. Emerg Infect Dis. Sep-Oct;5(5):607-25.
3. Karst SM, Wobus CE, Lay M, Davidson J, Virgin HW 4th. 2003. STAT1-dependent innate immunity to a Norwalk-like virus. Science. Mar 7;299(5612):1575-8.
4. Wobus CE, Thackray LB, Virgin HW 4th. 2006. Murine norovirus: a model system to study norovirus biology and pathogenesis. J Virol. Jun;80(11):5104-12.
5. Cannon JL, Papafragkou E, Park GW, Osborne J, Jaykus LA, Vinjé J. 2006. Surrogates for the study of norovirus stability and inactivation in the environment: aA comparison of murine norovirus and feline calicivirus. J Food Prot. Nov;69(11):2761-5.
6. A.H. Shukla1, K. Mattison1, S. Bidawid1, and J.M. Farber. 2006. Characterization of the Physical Properties of Murine Norovirus-1 (MNV-1). Book of Abstracts -2006 Health Canada Science Forum Proceedings, Abstract # 1.39
7. Bae J, Schwab KJ. 2008. Evaluation of murine norovirus, feline calicivirus, poliovirus, and MS2 as surrogates for HNV in a model of viral persistence in surface water and groundwater. Appl Environ Microbiol. Jan;74(2):477-84.
8. Centers for Disease Control and Prevention: Norovirus in Healthcare Facilities Fact Sheet, Released December 21, 2006

New Clinical Microbiology facility launched – May 2008

After expanding in 2004 with the addition of its state-of-the art BSL-3 laboratory, MICROBIOTEST has grown again. Our new Microbiology Clinical facility opened in May. This 3,000 square foot unit at 109 Carpenter Drive located in the complex adjacent to our 105 Carpenter Drive headquarters was configured to maximize laboratory operations and streamline the process.

This larger facility has enhanced our sample processing capabilities by adding three stations (for a total of five), resulting in a substantial increase of the number of subjects treated each day. In addition, the new Clinical operation houses two separate and distinct Clinical laboratories within one facility, permitting us to run separate studies simultaneously. With the increasing demand for FDA Phase-2 clinical trials for antiseptics, MBT is in a superior position to provide the best testing services for its clients.

If you are interested in conducting future Clinical trials for skin care products at MICROBIOTEST and would like preliminary pricing, or if you are interested in touring this new Clinical facility, please contact us at services@microbiotest.com.