Semi-nested Reverse Transcription-polymerase Chain Reaction Research Articles

Expression of Melanoma Antigen Genes A11 and A12 in Non-Small Cell Lung Cancer

Highlights:1. In this study, new primers designed using the semi-nested polymerase chain reaction (PCR) method were utilized to identify MAGE-A11 and MAGE-A12 expressions in specimens collected from core biopsy, forcep biopsy, and bronchoalveolar lavage.2. The histopathological analysis revealed positive expressions of MAGE-A11 and MAGE-A12 in specimens diagnosed with non-small cell lung cancer (NSCLC) as well as in specimens with no malignant cells. AbstractThe melanoma antigen gene (MAGE) belongs to the group of cancer testis antigens that are exclusively expressed in germ cells but may be re-expressed in cancer cells. The highly expressed MAGE-A subfamily in lung cancer may potentially be a diagnostic and prognostic biomarker. This study aimed to identify MAGE-A11 and MAGE-A12 expressions in lung tumors obtained from core biopsy, forceps biopsy, and bronchoalveolar lavage specimens. A cross-sectional observational study was conducted on 90 patients clinically diagnosed with lung tumors. These patients received core biopsy, forceps biopsy, and bronchoalveolar lavage interventions after ethical approval was obtained. The complementary deoxyribonucleic acid (cDNA) quality was assessed by the polymerase chain reaction (PCR) of glyceraldehyde-3-phosphate dehydrogenase (GAPDH). The assessment was performed to ascertain if all specimens exhibited positive PCR amplification of the GAPDH gene. MAGE-A11 and MAGE-A12 were identified through a semi-nested reverse transcription PCR. The positive results were detected by measuring the PCR products, with MAGE-A11 and MAGE-A12 measuring at base pairs (bp) of 858 and 496 in the first and second rounds, respectively. The expressions of MAGE-A11 and MAGE-A12 were observed in 3 (3.33%) and 40 (44.44%) out of 90 specimens, respectively. The prevalence rate of non-small cell lung cancer (NSCLC) was 31.11% (28/90). Among these cases, 3.57% (1/28) showed the expression of MAGE-A11, while 32.14% (9/28) exhibited the expression of MAGE-A12. Sixty-two (68.89%) out of 90 patients were diagnosed with no tumor cell malignancy. Out of 62 cases, 2 (3.23%) exhibited the expression of MAGE-A11, while 31 (50%) demonstrated the expression of MAGE-A12. MAGE-A11 and MAGE-A12 were detected in NSCLC and in certain specimens with a pathological diagnosis that indicated the absence of malignant cells. In conclusion, MAGE A11 and MAGE A12 have potential markers that can improve the pathological diagnosis of lung cancer. Further investigation is necessary to explore the expression of MAGE-A in correlation with lung cancer progression.

MOLECULAR CHARACTERIZATION OF DENGUE VIRUS AND VECTORIAL COMPETENCE OF AEDES MOSQUITOES: A LOCAL MODEL OF XENOMONITORING

Dengue is a major public health concern throughout tropical and sub-tropical regions of the world. Dengue virus is transmitted by infected female mosquitoes mainly of the species of Aedes aegypti and Ae. albopictus.Vector of Aedes mosquito populations may present different levels of competence for arbovirus transmission.Therefore, this study aimed at detecting DENV serotypes circulating and vectorial competence of adult field collected Aedes populations from selected local government areas of Kaduna State, Nigeria. A total of 233 mosquitoes were collected, identified morphologically to species level using coloured identification keys of Rueda and dissected under a dissecting microscope each species identified was tested in a pools of 20 individuals. Their bodies and head/salivary glands were separated and transferred to separate microtubes. RNA extraction was done using viral RNA extraction kit and semi-nested reverse transcription-polymerase chain reaction (RT-PCR) was used to amplified for DENV serotypes in the head/salivary glands of the Aedes mosquitoes. The study morphologically identified Ae. aegypti, Ae. vittatus and Ae. Furcifer. Aedes aegypti is the most abundant species 77.3%(180/233) while Ae. furcifer 10.3% (24/233) were the least. DENV serotypes were detected in 76.9%(10/13) of the pools of Aedes mosquitoes in the study areas. DENV1-3 serotypes were detected in Ae. Aegypti, DENV2 was detected in Ae. vittatus and DENV 2 and 3 were detected in Ae. Furcifer. Dengue virus 2 was the most detected serotypes in the study areas. PCR pools screening infectivity prevalence were found to be 7.07% (95% CI- 3.38-11.77). Thus, the finding...

First report of putative Leishmania RNA virus 2 (LRV2) in Leishmania infantum strains from canine and human visceral leishmaniasis cases in the southeast of Brazil.

Leishmania RNA virus 1 (LRV1) is commonly found in South American Leishmania parasites belonging to the subgenus Viannia, whereas Leishmania RNA virus 2 (LRV2) was previously thought to be restricted to the Old-World pathogens of the subgenus Leishmania. In this study, we investigated the presence of LRV2 in strains of Leishmania (L.) infantum, the causative agent of visceral leishmaniasis (VL), originating from different hosts, clinical forms, and geographical regions. A total of seventy-one isolates were screened for LRV2 using semi-nested reverse transcription-polymerase chain reaction (RT-PCR) targeting the RNA-dependent RNA polymerase (RdRp) gene. We detected LRV2 in two L. infantum isolates (CUR268 and HP-EMO) from canine and human cases, respectively. To the best of our knowledge, this is the first detection of LRV2 in the New World.

Clinicopathological alteration of symptoms with serotype among dengue infected pediatric patients

Dengue fever is a self-limiting, acute febrile illness caused by an arbovirus. This infection may be asymptomatic or symptomatic with its potential life-threatening form as DHF/DSS. Severe dengue cases occur typically in children due to overproduction of proinflammatory and anti-inflammatory cytokines (called cytokines storm) as well as increased microvascular permeability in them. This study aimed to find circulating dengue serotype and their clinicopathological association among pediatric patients admitted to tertiary care hospitals in Kolkata, India. Overall, 210 patients were approached, among them, 170 dengue suspected children admitted to three tertiary care hospitals were included in this study. Dengue samples were screened for the presence of dengue NS1 antigen and IgM antibodies by enzyme-linked immunosorbent assay. Viral RNA was extracted from NS1 seropositive serum samples and subjected to molecular serotyping by semi-nested reverse-transcription polymerase chain reaction. All patients were followed up for clinical manifestations and biochemical parameters associated with dengue. Cocirculation of all four serotypes was observed and DENV2 was the major circulating strain. Physiological classification of associated clinical symptoms was done as per WHO guideline and represented as a percentage variable. A multivariate logistic regression approach was used for making a regression model including dengue-associated clinical symptoms with dengue positivity or negativity as dependent variables. Thrombocytopenia was observed in 69% of patients and the commonest bleeding manifestation was petechia. Liver function profiles of infected patients were observed during follow-up and represented using a box plot. A significant change in trends of dengue-associated clinical manifestations and differential expression of liver functional profile with different phases of transition of dengue fever was observed in this study population.

Detection and Genetic Correlation Analysis of Diarrhea Cases and Norovirus in Oysters in Yantai, China.

BackgroundThis study aimed to assess the correlation between Norovirus (NoV), diarrhea, and raw oysters from the eastern coastal areas of Yantai, Shandong, China.MethodsMarine oysters were selected from the three aquatic markets in Laishan district, Yantai City, in March 2019. Meanwhile, 100 fecal samples were collected from patients with diarrhea from the same areas during the same period. Nucleic acids were extracted from these samples and detected by employing reverse transcription polymerase chain reaction (RT-PCR) for NoV GI/GII. The VP1 gene of the coat protein of NoV was amplified by semi-nested RT-PCR and sequenced. Sequence comparison of VP1 was performed with BioEdit software, and the evolutionary tree was constructed with Mega7.0 software.ResultsOf the 151 oysters, 42 (27.8%) were positive for NoV. Among them, 32 (21.2%) were GII-positive, 10 (6.6%) were GI-positive, and one GI VP1 sequence was obtained in the oyster samples. Of 100 fecal samples from patients with diarrhea, 38 were GII-positive and 17 were GI-positive. Totally, 19 GII VP 1 sequences and eight GI VP 1 sequences were obtained. Two G1 VP 1 sequences in two fecal samples showed 98.7% nucleotide sequence identity and 99.1% amino acid sequence identity G1 VP 1 acquired in the oyster sample.ConclusionsThe results suggest that oysters may be responsible for the spread of NoV in Yantai, Shandong province, China.

A five-year retrospective study on the epidemiology of hand, foot and mouth disease in Sabah, Malaysia

Hand, foot, and mouth disease (HFMD) is endemic in Malaysia, with the number of cases increasing. Sabah has experienced several HFMD outbreaks, but information on the epidemiology and molecular characteristics of responsible viruses is scarce. In this study, data of 17,574 reports of HFMD cases in Sabah from 2015 to 2019 were extracted from a public health disease surveillance system and analyzed. Twenty-one swab samples from 13 children were collected from Beaufort, Sabah, during an outbreak in August 2018 for detection and serotyping of causative viruses by semi-nested reverse transcription-polymerase chain reaction (snRT-PCR) of the VP4–VP2 region and consensus degenerate hybrid oligonucleotide primer PCR of the VP1 region, respectively. Nucleotide sequencing and phylogenetic analysis were conducted by the neighbor-joining method. The average annual incidence of HFMD was 94.3 per 100,000 people, with the greatest yearly increase between 2017 and 2018. Swabs from six children were tested positive for enterovirus, of which five were positive for CVA16 and one for EV71. All CVA16 strains belonged to sub-genotype B1a, and the EV71 strain belonged to sub-genotype B5. Phylogenetic analyses indicate that enterovirus genotype shift might be responsible for the increasing trend of HFMD in Sabah, however, further study is needed.

Phylogenetic Study of VP6 Gene of Bovine Rotavirus A and Molecular Survey of Bovine Rotaviruses B and C, and Human G and P Genotypes of Rotavirus A in Calves in Iran

Background: Rotavirus (RV) is one of the most important causes of diarrhea in the calf and human neonates. Rotaviruses are divided into nine different serogroups, of which group A is more important compared to other groups. Objective: This study was performed because of the lack of information about the importance and prevalence of bovine rotaviruses B (RVB) and C (RVC) and human genotypes of rotavirus A (RVA) in the bovine population in Iran. Phylogenetic analysis of VP6 of bovine RVA was the second aim of the present study. Materials and Methods: A total of 581 stool specimens were collected from diarrheic calves of 14 provinces and were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and 485 of them were investigated by PAGE electrophoresis to determine the frequency of three rotaviruses A (RVA), B (RVB), and C (RVC). The presence of human G and P genotypes in Iranian bovine population was also evaluated using semi-nested multiplex RT-PCR. Results: RVA was detected by RT-PCR (VP6 gene detection) in 16.2% (94/581) and by PAGE in 22.16% (108/485) and no positive cases of RVB and RVC were confirmed by polyacrylamide gel electrophoresis (PAGE). This study showed that non-A RV groups (B and C) have little role in calf diarrhea in Iran. The results of the phylogenetic study of VP6 sequences of rotaviruses A identified in this study showed that they all belonged to genotype I2 and were classified into three different branches. Specimen isolated in Zanjan showed the highest difference (maximum identity of 94%) with other sequences and clustered along with the Japanese strain, R22. Human G and P genotypes were not found in the studied samples. Conclusion: The results showed that non-A rotaviruses and human genotypes of RVA are of little importance in calf rotavirus diarrhea in Iran. Also, there is the first phylogenetic study of rotavirus A VP6 protein in Iran.

Molecular characterization of group A rotavirus among children aged under 5 years in Tunisia, 2015-2017.

The aim of the present study was to report the molecular characterization of human group A rotaviruses (RVAs) circulating in Tunisia. Stool specimens were collected from children under 5 years of age who had been hospitalized or were consulting for gastroenteritis in Tunisian hospitals between 2015 and 2017. All samples were screened by reverse-transcription polymerase chain reaction (RT-PCR) for the detection of the VP6 gene specific for RVA. RVA-positive samples were further analysed for G/P genotyping by semi-nested multiplex RT-PCR. Among 454 tested samples, 72 (15.8 %) were positive for RVA. G1P[8] was the most prevalent detected strain (41.7%), followed by G9P[8] (32.8%), G2P[4] (7.5%), G12P[8] (7.5%), G1P[6] (3.0%), G2P[8] (1.5%) and G3P[8] (1.5%), with mixed infections in 4.5 % of cases. In the absence of a national anti-rotavirus vaccination strategy, RVAs remain the primary aetiological agent for gastroenteritis in Tunisian children.

Occurrence of norovirus genogroups I and II in recreational water from four beaches in Belém city, Brazilian Amazon region.

This study aimed to investigate the presence of norovirus (NoV) in recreational waters of four estuarine beaches located in Mosqueiro Island, Belém city, Brazilian Amazon, during two years of monitoring (2012 and 2013). NoV particles were concentrated on filtering membrane by the adsorption-elution method and detected by semi-nested RT-PCR (reverse transcription polymerase chain reaction) and sequencing. NoV positivity was observed in 37.5% (39/104) of the surface water samples, with genogroup GI (69.2%) occurring at a higher frequency than GII (25.7%), with a cocirculation of both genogroups in two samples (5.1%). This virus was detected in all sampling points analyzed, showing the highest detection rate at the Paraíso Beach (46.2%). Statistically, there was a dependence relationship between tide levels and positive detection, with a higher frequency at high tide (46.7%) than at low tide (25%) periods. Months with the highest detection rates (April 2012 and April/May 2013) were preceded by periods of higher precipitation (March 2012 and February/March 2013). Phylogenetic analysis showed the circulation of the old pandemic variant (GII.4-US_95-96) and GI.8. The NoV detection demonstrated viral contamination on the beaches and evidenced the health risk to bathers, mainly through recreational activities such as bathing, and highlighted the importance of including enteric viruses research in the recreational water quality monitoring.

Respiratory syncytial virus genotypes NA1, ON1, and BA9 are prevalent in Thailand, 2012-2015.

Respiratory syncytial virus (RSV) causes acute lower respiratory tract infection in infants and young children worldwide. To investigate the RSV burden in Thailand over four consecutive years (January 2012 to December 2015), we screened 3,306 samples obtained from children ≤5 years old with acute respiratory tract infection using semi-nested reverse-transcription polymerase chain reaction (RT-PCR). In all, 8.4% (277/3,306) of the specimens tested positive for RSV, most of which appeared in the rainy months of July to November. We then genotyped RSV by sequencing the G glycoprotein gene and performed phylogenetic analysis to determine the RSV antigenic subgroup. The majority (57.4%, 159/277) of the RSV belonged to subgroup A (RSV-A), of which NA1 genotype was the most common in 2012 while ON1 genotype became prevalent the following year. Among samples tested positive for RSV-B subgroup B (RSV-B) (42.6%, 118/277), most were genotype BA9 (92.6%, 87/94) with some BA10 and BA-C. Predicted amino acid sequence from the partial G region showed highly conserved N-linked glycosylation site at residue N237 among all RSV-A ON1 strains (68/68), and at residues N296 (86/87) and N310 (87/87) among RSV-B BA9 strains. Positive selection of key residues combined with notable sequence variations on the G gene contributed to the continued circulation of this rapidly evolving virus.

Norovirus genogroups I and II in environmental water samples from Belém city, Northern Brazil.

This study investigated the presence of norovirus (NoV) GI and GII in environmental samples from the northern region of Brazil. Water samples were collected monthly (November 2008/October 2010) from different sources and sewage and concentrated by the adsorption-elution method. The NoV investigation used molecular methods followed by sequencing reactions. The general positivity for NoV was 33.9% (57/168). Considering the results obtained only in the semi-nested RT-PCR (reverse transcription polymerase chain reaction) and only in the TaqMan® real-time PCR, the rates were 26.8% (45/168) and 27.4% (46/168), respectively, being for NoV GI 22.2% (10/45) and 19.6% (9/46); for GII 17.8% (8/45) and 15.2% (7/46); and for GI + GII 60% (27/45) and 65.2% (30/46), respectively. Different GI (GI.1, GI.4, GI.7 and GI.8) and GII (GII.4, GII.6, GII.9, GII.12 and GII.14) genotypes were detected. These results demonstrated the NoV was disseminated in the waters of Belém city due to a lack of sanitation that allowed the discharge of contaminated effluents into these aquatic ecosystems.

Elevated Expression of the Testis-specific Gene WBP2NL in Breast Cancer.

Breast cancer is one of the most common causes of cancer death in women; therefore, the study of molecular aspects of breast cancer for finding new biomarkers is important. Recent studies have shown that WW domain-binding protein 2 (WBP2) is important for the oncogenic property of breast cancer. WWP2 N-terminal-like (WBP2NL) is a testis-specific signaling protein that induces meiotic resumption and oocyte activation events. Our previous study revealed that WBP2NL gene expression is elevated in actively dividing cells and it might be associated with cellular proliferation and tumorigenic process. However, the clinical relevance and importance of WBP2NL gene in cancer has not been understood yet. Therefore, we were interested in analyzing the expression of WBP2NL gene in human breast cancer tissues and breast cancer cell lines, for the first time. We used reverse transcription-polymerase chain reaction (RT-PCR) and semi-nested RT-PCR to evaluate the expression of WBP2NL in malignant breast cancer and adjacent noncancerous tissue (ANCT) samples, as well as MCF-7 and MDA-MB-231 cell lines. The WBP2NL gene was expressed in 45 out of 50 (90%) breast cancer tissues and overexpressed in the MDA-MB-231 cell line. We suggest that WBP2NL may play roles in breast cancer activation maybe through binding to a group I WW domain protein. The elevated expression of WBP2NL gene in breast cancer and MDA-MB-231 cell line leads us to suggest that WBP2NL might be considered as a novel prognostic factor for early diagnosis of breast cancer.

Molecular surveillance of rotavirus strains circulating in Yaoundé, Cameroon, September 2007–December 2012

Rotavirus is the most common cause of severe diarrheal disease in children under 5years of age worldwide. The World Health Organization (WHO) estimated that 453,000 rotavirus-attributable deaths occur annually. Through the WHO, the Rotavirus Sentinel Surveillance Program was established in Cameroon in September 2007 with the Mother and Child Center (MCC) in Yaoundé playing the role of sentinel site and national laboratory for this program. The objectives of this surveillance were to assess the rotavirus disease burden and collect baseline information on rotavirus strains circulating in Cameroon. Diarrheal stool samples were collected in a pediatric hospital from children under 5, using the WHO case definition for rotavirus diarrhea. Antigen detection of rotavirus was performed by using an enzyme immunoassay (EIA). The genotypic characterization was performed using multiplexed semi-nested reverse transcription-polymerase chain reaction (RT-PCR) assays. Between September 2007 and December 2012, 2444 stool samples were received at the MCC laboratory for rotavirus antigen detection, of which 999 (41%) were EIA positive. Among EIA positive samples 898 were genotyped. Genotype prevalence varied each year. Genotype G9P[8] was the dominant type during 2007 (32%) and 2008 (24%), genotype G3P[6] predominated in 2010 (36%) and 2011 (25%), and G1P[8] was predominant in 2012 (44%). The findings showed that the rotavirus disease burden is high and there is a broad range of rotavirus strains circulating in Yaoundé. These data will help measure the impact of vaccination in the future.

Occurrence of hepatitis E virus infection in acute hepatitis in Thailand

Hepatitis E virus (HEV) infection is one of the enterically transmitted types of hepatitis. The present study was undertaken to estimate the occurrence of HEV infection in sporadic acute hepatitis in Thailand. Serum samples were obtained from 614 suspected acute hepatitis patients at two large hospitals in Bangkok during 2008, 2009, and 2011. Acute hepatitis E was identified by the presence of anti-HEV IgM (4.8%) using indirect ELISA kits and/or HEV RNA (4.5%) by a semi-nested reverse transcription-polymerase chain reaction assay. HEV IgM was the most common marker for detection (77%) at diagnosis, either by positive HEV IgM alone or together with HEV RNA, whereas HEV RNA alone was detected in 23% of patients. Overall, 4.2% of cases (26 out of 614) were acute HEV infection with the highest attack rate in the elderly age group. In addition, nucleotide sequence analysis of five HEV samples revealed 92.8-99.8% homology. All viruses were clustered into HEV genotype 3 and were similar genetically to swine HEV strains previously detected in the same area. Therefore, the occurrence of HEV infection with closely related to swine genotype 3 was approximately 4-5% of acute hepatitis cases in Thailand. Anti-HEV IgM was the most common marker at diagnosis.

Coxsackievirus B infection is highly related with missed abortion in Korea.

PurposeThis study investigated the possible relationship between viral infection and first trimester pregnancy loss.Materials and MethodsA prospective study was performed on 51 gravidas with missed abortion, fetal anomaly, pre-term delivery, and full-tem delivery at Hanyang University Hospital. Enteroviruses were detected by semi-nested reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry in abortive tissues and placentas. Enterovirus serotypes were confirmed by genome sequencing. Herpesviruses were detected by PCR.ResultsCoxsackievirus B3 (CVB3) was detected in 8 of 14 missed abortion cases, 1 of 27 full-term cases, and none of the 9 pre-term cases. Coxsackievirus B1 (CVB1) was detected in an encephalocele case. Herpes simplex virus type 1 was found in 4 full-term cases, 3 pre-term cases, and none of the missed abortion cases.ConclusionThe prevalence of CVB3 was significantly higher in missed abortion cases compared to full-term or pre-term delivery cases. CVB infection may therefore be an important etiological agent of missed abortion.

Real-time PCR quantitative assessment of hepatitis A virus, rotaviruses and enteroviruses in the Tyume River located in the Eastern Cape Province, South Africa

We applied real-time RT-PCR (reverse transcription-polymerase chain reaction) to assess the incidence of hepatitis A virus, rotaviruses and enteroviruses in the Tyume River, an important water resource in the impoverished Eastern Cape Province of South Africa. Detection of noroviruses was done using conventional semi-nested RT-PCR. Water samples were collected once monthly from 6 sampling sites over a 12-month period starting in August 2010 and ending in July 2011. Hepatitis A virus was detected in 13% of the samples in concentrations ranging between 1.67×10 3 genome copies/l and 1.64×104 genome copies/l while rotaviruses were detected in 4% of the samples with concentrations ranging from 9×10 1 genome copies/l to 5.64×10 3 genome copies/l. Enteroviruses were not detected in any of the samples, while noroviruses were detected in 4% of the samples. All hepatitis A and rotaviruses positive samples were from the upstream sections of Tyume River while noroviruses were detected in samples from downstream sections only. Statistical analysis showed that occurrence of the viruses in Tyume River was sporadic. Risk analysis showed that hepatitis A virus posed greater risk than rotaviruses for both recreational and domestic water uses. Because of the low infectious dose of enteric viruses, the detection of even low concentrations of hepatitis A virus, rotaviruses and noroviruses in surface water poses a significant risk to public health. Keywords: Hepatitis A virus, rotaviruses, noroviruses, TaqMan real-time PCR, reverse transcription, Tyume River, public health

Identification of SL addition trans-splicing acceptor sites in the internal transcribed spacer I region of pre-rRNA in Leishmania (Leishmania) amazonensis

Trypanosomatidae is a family of early branching eukaryotes harbouring a distinctive repertoire of gene expression strategies. Functional mature messenger RNA is generated via the trans-splicing and polyadenylation processing of constitutively transcribed polycistronic units. Recently, trans-splicing of pre-small subunit ribosomal RNA in the 5' external transcribed spacer region and of precursor tRNAsec have been described. Here, we used a previously validated semi-nested reverse transcription-polymerase chain reaction strategy to investigate internal transcribed spacer (ITS) I acceptor sites in total RNA from Leishmania (Leishmania) amazonensis. Two distinct spliced leader-containing RNAs were detected indicating that trans-splicing reactions occur at two AG acceptor sites mapped in this ITS region. These data provide further evidence of the wide spectrum of RNA molecules that act as trans-splicing acceptors in trypanosomatids.

Improved diagnosis of spring viremia of carp by nested reverse-transcription PCR: Development of a chimeric positive control for prevention of false-positive diagnosis

Polymerase chain reaction (PCR) assays allow for the rapid and accurate detection of infectious agents through identification of nucleic acid sequences. However, contamination of samples with positive DNA can lead to false-positive results. In this study, positive control plasmids were developed to minimize false-positive reactions due to PCR contamination during detection of SVCV by semi-nested reverse-transcription PCR. An ampicillin resistance gene was truncated by PCR amplification, and the fragments were inserted into pGEM-T Easy vectors; the resulting plasmids were named SVCV chimeric plasmid-1 and chimeric plasmid-2, respectively. Through a series of semi-nested PCRs, the use of SVCV chimeric plasmids-1 and -2 was shown to ensure correct diagnoses, free from PCR contamination. The results of this study show that PCR positive controls can be created without use of viral nucleic acids or pathogen-infected tissues. The technique can be applied to quarantined material and can be used to detect other pathogens.

Asian sand dust enhances rhinovirus-induced cytokine secretion and viral replication in human nasal epithelial cells

Context: Asian sand dust (ASD) originating in the arid deserts of Mongolia and China causes annual severe air pollution events in the Asia-Pacific area, including Korea, Japan, and China. ASD is thought to impact public health by aggravating or inducing respiratory illness. Among the most common respiratory illnesses is the common cold caused by rhinovirus (RV) infection. To date, however, the impact of ASD on RV infection has not been studied.Objective: In this study, we investigated the effect of ASD on RV infection in human nasal epithelial cells.Methods: Primary human nasal epithelial cells grown at an air-liquid interface were treated with ASD and/or RV. After RV infections were confirmed using semi-nested reverse transcription-polymerase chain reaction (RT-PCR), mRNA expression and protein secretion of the inflammatory cytokines interferon-γ (IFN-γ), interleukin-1β (IL-1β), IL-6, and IL-8, indicators of the severity of RV-induced inflammation, were measured by real-time PCR and enzyme-linked immunosorbent assays. Viral titer was also assayed by culturing viruses to compare viral replication between RV-only and ASD-plus-RV groups.Results: ASD significantly increased RV-induced IFN-γ, IL-1β, IL-6, and IL-8 mRNA levels and protein secretion in primary nasal epithelial cells. In addition, ASD caused a significant increase in RV replication.Conclusions: Our results suggest that ASD may potentiate common cold symptoms associated with RV infection not only by enhancing IFN-γ, IL-1β, IL-6, and IL-8 secretion, but also by increasing viral replication.

Daggerblade grass shrimp ( Palaemonetes pugio): A reservoir host for yellow-head virus (YHV)

Yellow-head virus (YHV) is a major pathogen in penaeid shrimps. We surveyed 13 crustacean species in eight families from two orders that are commonly found in the Mississippi coastal area and freshwater environments as potential reservoir or carrier hosts of YHV. Using semi-nested polymerase chain reaction (PCR) on relatively small sample sizes, we did not detect any natural infection. However, when the daggerblade grass shrimp, Palaemonetes pugio, and the blue crab, Callinectes sapidus, were exposed to YHV by injection and per os, YHV was detected in the tissue of P. pugio and in the hemolymph of C. sapidus when tested by semi-nested reverse transcription PCR (RT-PCR) and real time quantitative reverse transcription PCR (qRT-PCR). YHV replicated in P. pugio, causing 8% mortality (9/112) after injection, with the viral titer reaching a peak at 14 days post-inoculation (dpi) and remaining detectable at 36 dpi. The number of infected animals and viral load, however, were relatively low but the virus still remained infectious to penaeids when administered by feeding. When YHV was injected into P. pugio, in situ hybridization detected a positive response to it at 7 dpi in connective tissue of hepatopancreas, muscle, and midgut. Viral RNA in injected C. sapidus remained at a low level for 3 days, and it was not detected from 7 dpi onwards. In fed C. sapidus, the viral RNA reached a peak at 3 dpi and still detectable at 7 dpi, but it became undetectable at 14 and 21 dpi. These data suggest that P. pugio under some conditions could act as a reservoir host for YHV but that the blue crab could serve as a poor, short term carrier host only.