Hepatitis A Virus Detection in Oysters (Crassostrea gigas) in Santa Catarina State, Brazil, by Reverse Transcription–Polymerase Chain Reaction

2003 ◽  
Vol 66 (3) ◽  
pp. 507-511 ◽  
Author(s):  
C. COELHO ◽  
A. P. HEINERT ◽  
C. M. O. SIMÕES ◽  
C. R. M. BARARDI

Shellfish are readily contaminated with viruses present in water containing sewage because of the concentration effect of filter feeding. Hepatitis A virus (HAV) is the main cause of acute hepatitis worldwide and may lead to severe illness or even death. It is transmitted through fecal and oral routes and causes widespread endemic and asymptomatic infections in young children. Here we describe a method for the detection of HAV RNA in shellfish involving the extraction of total RNA from oyster meat followed by reverse transcription–polymerase chain reaction (RT-PCR). Virus recovery from oyster extracts artificially seeded with HAV strain HM 175 was examined by RT-PCR. The minimum detection limit was 3.3 focus-forming units of HAV, and the recovery rate was 75.7%. This method was used to assess the viral contamination of four shellfish beds in Santa Catarina State, Brazil, over a 1-year period. Six (22%) of 27 samples collected in autumn and winter from one shellfish bed tested positive for HAV.

2003 ◽  
Vol 66 (2) ◽  
pp. 331-334 ◽  
Author(s):  
DAVID H. KINGSLEY ◽  
GARY P. RICHARDS

We investigated the ability of hepatitis A virus (HAV) to persist for up to 6 weeks in Eastern oysters (Crassostrea virginica). Viral RNA was detected by reverse transcription–polymerase chain reaction 6 weeks after 16 h of exposure to 90,000 PFU (180 PFU/ml of seawater) of HAV. Assaying for infectious virus in oysters that received a daily feeding of phytoplankton recovered 3,800, 650, and 500 PFU of HAV 1, 2, and 3 weeks after contamination with 90,000 PFU of HAV, respectively. However, no infectious HAV was isolated from oysters 4, 5, or 6 weeks after contamination. These results support the position that shellfish depuration is insufficient for the complete removal of infectious viruses. Extended relay times (in excess of 4 weeks) may be required to produce virologically safe shellfish.


1999 ◽  
Vol 62 (10) ◽  
pp. 1210-1214 ◽  
Author(s):  
SORAYA I. ROSENFIELD ◽  
LEE-ANN JAYKUS

A multiplex reverse transcription polymerase chain reaction (RT-PCR) method was developed for the simultaneous detection of the human enteroviruses, hepatitis A virus (HAV) and Norwalk virus (NV). Poliovirus type 1 (PV1) was chosen as a model for the human enterovirus group. Three different sets of primers were used to produce three size-specific amplicons of 435 bp, 270 bp, and 192 bp for PV1, NV, and HAV, respectively. RT-PCR products were separated by agarose gel electrophoresis, and amplicon identity was confirmed by Southern transfer followed by DNA hybridization using nonradio-active, digoxigenin-labeled internal probes. When tested on mixed, purified virus suspensions, the multiplex method achieved detection limits of ≤1 infectious unit (PV1 and HAV) or RT-PCR-amplifiable unit (NV) for all viruses. With further streamlining efforts such as single tube amplification and liquid hybridization, multiplex PCR offers advantages over cell culture methodology and monoplex PCR because it allows for rapid and cost-effective detection of several human enteric viruses in a single reaction tube.


1998 ◽  
Vol 44 (3) ◽  
pp. 298-302 ◽  
Author(s):  
Charlotte Arnal ◽  
Virginie Ferré-Aubineau ◽  
Bernard Besse ◽  
Sylviane Billaudel

Reverse transcription polymerase chain reaction, using either nested or seminested primers, is used extensively for the detection of viruses in small quantities. However, existing methods are prone to false positive reactions. We report here an improved polymerase chain reaction technique based on the use of longer primers (39 nucleotides) with single-step amplification, applied to the detection of hepatitis A in low quantities. While the sensitivity of this technique (10 x the 50% tissue culture infective dose) is equivalent to that of existing methods, it is a simpler procedure, less time consuming, and less susceptible to contamination and therefore provides a more reliable tool for routine diagnosis. Finally, the development of a DNA enzyme immunoassay detection technique and the complete automation of the procedure allow a large number of samples to be processed in clinical laboratories.Key words: long primers, hepatitis A virus, reverse transcription polymerase chain reaction, seminested PCR, DNA enzyme immunoassay.


2006 ◽  
Vol 175 (4S) ◽  
pp. 485-486
Author(s):  
Sabarinath B. Nair ◽  
Christodoulos Pipinikas ◽  
Roger Kirby ◽  
Nick Carter ◽  
Christiane Fenske

2003 ◽  
Vol 15 (2) ◽  
pp. 99 ◽  
Author(s):  
Paisan Tienthai ◽  
Naoko Kimura ◽  
Paraskevi Heldin ◽  
Eimei Sato ◽  
Heriberto Rodriguez-Martinez

Hyaluronan (HA) has been related to fertilization and embryo development in the pig. Furthermore, HA is present in pig oviduct fluid and the lining epithelium, particularly of the pre-ovulatory sperm reservoir. Because the mechanisms that regulate HA synthesis have not yet been clarified, semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) was conducted to assess the expression of mRNAs of two HA-synthesizing enzymes (has2 and has3) in the oviduct epithelium (uterotubal junction, isthmus, ampullary–isthmic junction and ampulla segments) of non-inseminated (control) and inseminated (treatment) sows at pre-, peri- and post-ovulatory oestrus. Only has3 mRNA was detected; it was present in all tubal segments of both control and treatment samples. The level of has3 expression did not vary significantly between non-inseminated and inseminated specimens, but there was a tendency (NS) for increased mean values during the peri- and post-ovulatory stages compared with pre-ovulation. It is concluded that has3 is expressed by the porcine endosalpinx epithelium and the levels of expression do not vary during the critical periods of sperm transport and fertilization, despite fluctuating levels of HA in the tubal fluid at corresponding periods.


Sign in / Sign up

Export Citation Format

Share Document