scholarly journals Assessment of Microbial Reduction by Cage Washing and Thermal Disinfection using Quantitative Biologic Indicators for Spores, Viruses and Vegetative Bacteria

2021 ◽  
Vol 60 (5) ◽  
pp. 529-538
Author(s):  
Jean-Philippe Mocho ◽  
Romuald Coutot ◽  
Mike Douglas ◽  
Lea Szpiro ◽  
Dounia Bouchami ◽  
...  
Keyword(s):  
Quality Standard ◽  
Reduction Factor ◽  
Microbial Reduction ◽  
Microbial Load ◽  
Minute Virus Of Mice ◽  
Data Loggers ◽  
Test Soil ◽  
Minute Virus ◽  
Thermal Disinfection ◽  
Minimum Quality

Cage washing is a key process of the biosecurity program in rodent facilities. For the current study, we developed systems (i. e., magnet attachments, quantitative biologic indicators (Q-BI), and measurement of thermal disinfection at equipment level) to assess the microbial decontamination achieved by a rodent equipment washer with and without thermal disinfection. 99% of the magnets remained in position to hold Q-BI and temperature probes inside cages, water bottles or at equipment level across a cabinet washer chamber with loads dedicated to either housing or drinking devices. Various types of Q-BI for Bacillus atrophaeus, Enterococcus hirae and minute virus of mice were tested. To simulate potential interference from biologic material and animal waste during cage processing, Q-BI contained test soil: bovine serum albumin with or without feces. As a quantitative indicator of microbial decontamination, the reduction factor was calculated by comparing microbial load of processed Q-BI with unprocessed controls. We detected variation between Q-BI types and assessed the washer's ability to reduce microbial load on equipment. Reduction factor results were consistent with the Q-BI type and showed that the washing and thermal disinfection cycle could reduce loads of vegetative bacteria, virus and spore by 5 log10 CFU/TCID50 and beyond. Thermal disinfection was monitored with temperature probes linked to data loggers recording live. We measured the period of exposure to temperatures above 82.2 °C, to calculate A0, the theoretical indicator for microbial lethality by thermal disinfection, and to assess whether the cabinet washer could pass the minimum quality standard of A0 = 600. Temperature curves showed an A0 > 1000 consistently across all processed equipment during thermal disinfection. These data suggest that, when sterilization is not required, a cabinet washer with thermal disinfection could replace an autoclave and reduce environmental and financial waste.

A precise map of splice junctions in the mRNAs of minute virus of mice, an autonomous parvovirus.

1986 ◽  
Vol 59 (3) ◽  
pp. 564-573 ◽  
Author(s):  
C V Jongeneel ◽  
R Sahli ◽  
G K McMaster ◽  
B Hirt
Keyword(s):  
Minute Virus Of Mice ◽  
Minute Virus ◽  
Splice Junctions

Parvovirus infection in children and pregnant women

2021 ◽  
Vol 19 (2) ◽  
pp. 119-125
Author(s):  
E.V. Mikhailova ◽  
◽  
T.K. Chudakova ◽  
D.Yu. Levin ◽  
A.V. Romanovskaya ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Ex Vivo ◽  
Parvovirus B19 ◽  
Virus Transmission ◽  
Intrauterine Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Minute Virus Of Mice ◽  
Gestation Age ◽  
B19 Parvovirus ◽  
Minute Virus

Parvovirus (PV) is a widespread infection, despite the fact that this pathogen was discovered only recently. The therapeutic effect of PV, in particular its oncolytic activity, is being actively studied now. Notably, PVs causing infections in animals, such as rat PV H-1, caninae PV, and rodent protoparvovirus (minute virus of mice) suppress oncogenesis in these animals. There is an ex vivo evidence of rat glioblastoma and gliosarcoma sensitivity to PV. The affinity of PV B19 to P-antigen located primarily on the membranes of erythroid cells is crucial for the disease pathogenesis. The teratogenic effect of PV B19 is associated with its ability to infect placental cells (P-antigen is present on the cells of chorionic villi and surface of the trophoblast). PV infection can be acquired or congenital, typical or atypical. The outcome of intrauterine infection with PV B19 largely depends on the gestation age when the infection occurred. Women infected during the second trimester are at higher risk of vertical transmission and severe intrauterine pathology with a poor outcome than those infected during the third trimester. Constant contact with young children significantly increases the risk of PV B19 infection among pregnant women with no immunity to this virus. Serum is the most convenient biomaterial for detecting both PV DNA and virus-specific antibodies. One test for anti-PV IgG using enzyme-linked immunosorbent assay is sufficient to determine the immune status of a patient. Polymerase chain reaction with amniotic fluid is used to diagnose intrauterine infection with PV B19. Blood components and products should be checked for PV B19. High frequency of PV B19 detection in the blood of donors necessitates the development of special measures aimed at prevention of virus transmission. Key words: pregnant women, children, parvovirus B19, parvovirus infection

Standard minimi di qualitŕ: un approccio teorico

2012 ◽  
pp. 29-41
Author(s):  
Grassi Iacopo
Keyword(s):  
High Standard ◽  
Policy Instrument ◽  
Quality Standard ◽  
Average Quality ◽  
Proposed Model ◽  
Positive Externality ◽  
Experience Good ◽  
The Government ◽  
Minimum Quality

At least since Akerlof (1970), asymmetric information in the case of experience goods has been a central issue in the economic literature. This paper studies regulation in markets where the quality of the experience good is never completely verifiable by consumers even after purchase. In the proposed model firms can decide the quality of the good: always producing a high quality good creates a positive externality in the market, but it causes an incentive to the firms to deviate and produce low quality goods. The main policy instrument for the government, in order to maximize Social Welfare, is to fix a minimum quality standard, but imposing a too high standard might, in some cases, lower the average quality of the good in the market.

Experimental Assessment of Strength Parameters of River Sand for Sandcrete Block Production

2021 ◽  
Vol 53 ◽  
pp. 67-75
Author(s):  
Babatunde Ogunbayo ◽  
Clinton Aigbavboa ◽  
Opeoluwa Akinradewo
Keyword(s):  
Compressive Strength ◽  
Quality Standard ◽  
Sieve Analysis ◽  
Building Structures ◽  
Strength Parameters ◽  
River Sand ◽  
Sieve Analyses ◽  
Aggregate Material ◽  
Average Compressive Strength ◽  
Minimum Quality

Sandcrete block is a vital building material used in the construction of building structures. The sandcrete blocks are produced by different manufacturers using river sand obtained from different locations as aggregate material without recourse to the minimum quality standard for the blocks produced. The study assessed the strength parameters of river sand used as an aggregate material in block production to determine its quality and suitability in relation to the strength of block produced. Three (3) block manufacturing sites in Nigeria were visited and 27 (twenty-seven) blocks of size 450 mm x 225 mm x 225 mm were selected randomly from the sites. The properties of the river sand was analyzed through sieve analyses, bulk density, silt content and water absorption while the compressive strength of the blocks was also tested. The result of sieve analysis of the river sand used in block production for this study all satisfied the particle size requirements of BS EN 933-1:1997 for general construction work including block production. The result of the study also shows that blocks produced with the river sand after 28days have an average compressive strength of 1.23 N/mm2 (SW), 1.54 N/mm2 (SE) and 1.95N/mm2 (NE). The study, therefore, concluded and recommended that regulatory and professional bodies in partnership with relevant associations should organize seminars for producers of sandcrete blocks on the best practices involved in producing quality sandcrete blocks.

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