Monkey Kidney Cell Cultures Research Articles

Inhibitory activity of Euterpe oleracea Mart. fruit extract in West Nile virus infection

West Nile virus (WNV) is a neurovirulent arbovirus whose epidemic capacity is enhanced by the wide occurrence of competent vectors and susceptible avian amplifying hosts. In this study, we investigated the antiviral potential of Euterpe oleracea Mart. fruit extract (EoFE) in WNV infection of monkey kidney (Vero) cell cultures. A chromatographic authentication of the extract revealed a typical two-peak fingerprint attributable to the major anthocyanins of the fruit. As assessed by plaque assays in Vero cells, the extract showed a significant concentration-dependent antiviral effect when present throughout the infection procedure, reaching a maximum inhibition of 66.8% at 2 mg/mL without significant cytotoxicity or direct action on virus particles. A time-of-addition assay revealed that this anti-WNV effect was mostly exerted after virus entry, as incubation of Vero cells with EoFE before or during virus addition resulted in a nonsignificant decrease of infection efficiency. These results demonstrated a promising potential of EoFE in inhibiting WNV infection that can be further explored as an antiviral strategy.

In Vitro Evaluation of Anti-Hemolytic and Cytotoxic Effects of Traditional Mexican Medicinal Plant Extracts on Human Erythrocytes and Cell Cultures.

Plant extracts of fifteen plants of ethnomedicinal use in Mexico were analyzed to provide scientific knowledge of their medicinal properties through the evaluation of different biological activities such as anti-hemolytic, antioxidant, and cytotoxic effects in normal cells. Therefore, methanolic extracts were obtained from each of the plants by the Soxhlet extraction. The hemolytic activity in human erythrocytes was evaluated, as was their potential to protect the erythrocyte membrane against the 2,2'-azobis (2-methylpropionamidine) dihydrochloride (AAPH) and 1,1-diphenyl-2-picryl hydrazyl (DPPH) radicals. Finally, the toxicity of the extracts in normal cell cultures of African green monkey kidney cells (Vero) and peripheral blood mononuclear cells (PBMC) was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction method. Most of the extracts showed low hemolytic activity and high anti-hemolytic activity as well as high selectivity indices (SI) and antioxidant effects. Extracts of H. inuloides, J. dioica, and J. spicigera induced cell proliferation of the Vero cells. K. daigremontiana, A. adstringens, S. mexicanum, J. spicigera, L. tridentata, and M. tenuiflora extracts showed PBMC cell proliferation. In the present study, it was observed that the evaluated extracts did not present hemolytic activity, and some presented low toxicity when Vero and PBMC cell cultures were exposed. In conclusion, traditionally used plants possess beneficial health properties, and it is hoped that this study will serve as a basis for understanding the biological effects of traditionally used plants and may complement future studies.

Analysis of Toxicity of Recombinant Pneumolysin from Streptococcus pneumoniae.

We studied toxicity of recombinant Streptococcus pneumoniae pneumolysin protein in experiments on mice and its cytopathogenic effect on cultures of Vero green monkey kidney cells and human lung carcinoma A549 cells in vitro. In vivo and in vitro experiments proved the absence of compromised toxicity and direct cytopathogenic action of the recombinant protein.

Lanthanide-modified graphene oxide and nanodiamond materials and their cytotoxicity

Integrating lanthanide elements with carbon-based nanomaterials results in the creation of hybrid materials and nanocomposites with unique properties. We report a functionalization approach free of organic solvents for modifying graphene oxide (GO) and nanodiamond (ND) with various lanthanides (La(III), Ce(III), Eu(III), Gd(III), Tb(III) and Ho(III)). The aqueous-phase impregnation with their acetates was followed first by drying at 80 °C and then by heating at 300 °C for 2 h in air conditions. Scanning electron microscopy revealed that after the initial drying, the samples exhibited the presence of larger lanthanide-containing particles, whereas after the heating at 300 °C they became indistinguishable, and thus the lanthanide species became more homogeneously distributed throughout GO and ND. The toxicity, which is commonly associated with the presence of lanthanides, was evaluated in terms of the ability to inhibit the proliferation of COS-7 monkey kidney cell cultures. Most composites demonstrated a dose-dependent toxicity, with significantly lower cytotoxic effects compared to both the thermally treated GO and ND, as well as the pristine GO. The composites functionalized with gadolinium were among the least toxic at the maximum tested concentration (100 µg/ml). The ND-based composites were not cytotoxic at 50 µg/ml, the lowest tested concentration.

Kidney cell culture Macaca fascicularis as a candidate for vaccine development and in vitro model.

Cell culture is the proliferation of a cell population in vitro by isolating from the original tissue or growing from existing ones. One essential source is the monkey kidney cell cultures which have an essential role in biomedical study. This is due to the significant homology between the human and macaque genomes making these useful for cultivating human viruses, especially enteroviruses, and growing vaccines. This study developed cell cultures derived from the kidney of Macaca fascicularis (Mf) and validated its gene expression. The primary cultures were successfully subcultured up to six passages, grew as monolayers, and exhibited epithelial-like morphology. The cultured cells remained heterogeneous in phenotype and they expressed CD155 and CD46 as viral receptors, cell morphology (CD24, endosialin, and vWF), proliferation, also apoptosis markers (Ki67 and p53). These results indicated that the cell cultures can be used as in vitro model cells for vaccine development and bioactive compound.

Experimental evaluation of the activity of the product meflochine against coronavirus SАRS-CoV-2

When evaluating the effectiveness of the drug Mefloquine against SARS-Cov-2 coronavirus, in vitro experiments examined its toxicity for African green monkey kidney cell culture - Vero C1008, as well as antiviral activity against SARS-Cov-2, which was evaluated by suppressing the cytopathic effect the virus. A study of the toxicity of the drug Mefloquine showed that the concentration at which the drug exerts a cytopathic effect against 50% of Vero C1008 cells is 4.5 μg / ml. The maximum tolerated concentration (MTD) of Mefloquine is 2.25 μg / ml. A study of the effectiveness showed that 1 day after infection, the antiviral effect of Mefloquine was recorded when the drug was added 24 hours and 1 hour before infection with SARS-CoV-2, as well as when it was added 1 hour after infection, the cell culture was already at a concentration of 0.5 μg / ml Mefloquine at a concentration of 2 μg / ml, added to the Vero C1008 cell culture 1 hour after the introduction of SARS-CoV-2, completely blocked the action of the virus for 2 days after infection.

Isolation, molecular characterization, and in vitro schizogonic development of Sarcocystis sp. ex Accipiter cooperii from a naturally infected Cooper's hawk (Accipiter cooperii)

Raptors serve as the definitive host for several Sarcocystis species. The complete life cycles of only a few of these Sarcocystis species that use birds of prey as definitive hosts have been described. In the present study, Sarcocystis species sporocysts were obtained from the intestine of a Cooper's hawk (Accipiter cooperii) and were used to infect cell cultures of African green monkey kidney cells to isolate a continuous culture and describe asexual stages of the parasite. Two clones of the parasite were obtained by limiting dilution. Asexual stages were used to obtain DNA for molecular classification and identification. PCR amplification and sequencing were done at three nuclear ribosomal DNA loci; 18S rRNA, 28S rRNA, and ITS-1, and the mitochondrial cytochrome c oxidase subunit 1 (cox1) locus. Examination of clonal isolates of the parasite indicated a single species related to S. columbae (termed Sarcocystis sp. ex Accipiter cooperii) was present in the Cooper's hawk. Our results document for the first time Sarcocystis sp. ex A. cooperii occurs naturally in an unknown intermediate host in North America and that Cooper's hawks (A. cooperii) are a natural definitive host.

A comparative study of replicative properties of antitumor recombinant vaccinia viruses on human glioblastoma cell culture U87 and monkey kidney cell culture CV-1

In the world of today, virotherapy is one of the rapidly developing areas in the treatment of cancer, and its advantage is selective destruction of cancer cells with minimizing the destructive effect on normal cells of the body. A promising basis for the creation of oncolytic drugs is orthopoxviruses, which have a number of advantages over other viral vectors, and one of these advantages is a large capacity of the genome, which allows genes encoding proteins with antitumor properties to be cloned into their genome. In this study, we compared the replicative properties of ten variants of vaccinia virus (the strain LIVP of VACV) using human glioblastoma cell culture; some of these viruses have additional genes, such as the gene encoding granulocyte-macrophage colony stimulating factor, gene encoding apoptosis-inducing protein TRAIL and gene encoding green fluorescent protein. Furthermore, the virus with five virulence genes deleted (genes encoding hemagglutinin, γ-interferonbinding protein, thymidine kinase, complementbinding protein and Bcl2-like inhibitor of apoptosis), which has significantly lower reactogenicity and neurovirulence compared to the original strain LIVP of VACV, was studied. These data suggest that variants of vaccinia virus with a defective gene encoding thymidine kinase most actively replicate in glioblastoma cell culture.

Label‐Free Homogeneous Immunosensor Based on FRET for the Detection of Virus Antibody in Serum

As a member of the polyomaviridae family, simian vacuolating virus 40 (SV40), a non-enveloped small tumorigenic virus with a circular double-stranded DNA genome, was first identified in 1960 in cultures of rhesus monkey kidney cells. Its capsid with a diameter of about 45 nm is formed by 72 pentameric capsomers composed of three capsid proteins, VP1, VP2, and VP3. [1] The occurrence of nucleic acid sequences identical to those of SV40 has been reported in certain types of human tumors, including osteosarcoma, mesothelioma, choroid plexus tumors, and ependymomas. [2] Especially, SV40 is closely related to the human polyomaviruses BK virus (BKV) and JC virus (JCV), for the SV40 genome has about 70 % nucleotide sequence homology with the BKV and JCV genomes. [3] Besides, it has been suggested that antibody to the SV40 in low levels was found in human sera. [4] Thus, owing to the potential human health risk, the detection of antibody to SV40 in serum is expected to be a main approach to human cancer diagnosis relating to SV40. So far, the acknowledged detection method of antibodies to SV40 is serological. Levels of antibodies to SV40 can be measured by plaque inhibition neutralization assay, but the outcomes may take one to two weeks. Another widely used method is enzyme immunoassay (EIA) technology, which is the preferred method for measurement of antiviral antibodies, because it provides greater sensitivity and precision than tissue-culture-based assays. [5] However, the assay is inconvenient and unsuitable for the rapid and simple determination of antibody, due to laboratory operation and the need for skilled technicians and special facilities. [6] To overcome these drawbacks, a homogeneous immunoassay without any separation step could allow the detection of targets by ligand binding interactions under physiological conditions. [7] Besides, fluorescence has been selected for signal output due to its rapidness, simplicity, sensitivity, and reproducibility. [8] Fortunately, it has been found that the SV40 VP1 alone has the capacity to package the viral minichromosome [9] and then efficiently self-assembles to form SV40 virus-like particles (SVLP) in vitro, and that it can be used to encapsulate quantum dots through molecular self-assembly to form SLVP-QDs chimeric particles. [10] SVLP and SVLP-QDs chimeric particles both can stably exist in the presence of appropriate salt concentration and Ca 2 + over a pH range from 5 to 8. [11] Given a hint by that, we report herein a label-free homogenous fluorescence immunosensor for anti-SV40 antibody in serum for the first time. The immunosensor is based on fluorescence resonance energy transfer (FRET) where SVLP-QDs and graphene oxide (GO) are the energy donor and acceptor, respectively. QDs have always been a popular choice of energy donor [12] in FRET because of a variety of distinguished optical features, including high quantum yield, broad excitation spectra, narrow emission spectra, and photobleaching resistance. [13] However, the labeling the surface of a virus with QDs may affect the viral infectivity and the immunogenicity. [14] SVLP-QDs can solve these problems excellently and keep the strong fluorescence of QDs. But as a coin has the other side, SVLP-QDs may increase the distance between donor and acceptor, which will interfere with the efficiency of FRET. Theoretical calculations have indicated that graphene could act as a superquencher of organic dyes, as a result of nonradiative transfer of electronic excitation energy from dye excited states to the p system of graphene. The rate of this long-range resonance energy transfer was suggested to have a d 4 dependence on distance d, in sharp contrast to traditional FRET, for which the rate has a d 6 dependence. [15] Graphene and GO were widely used as acceptors and exhibited high efficiency in quenching the donor fluorescence emission. [16] Thus, GO was selected as the acceptor, and a FRET-based immunosensor was developed. We revealed the energy transfer from SVLP-QDs to GO and constructed an immunosensing platform which could be used for rapid, inexpensive, and easy-to-perform detection of anti-SV40 antibody directly in serum.

Evaluation of different embryonating bird eggs and cell cultures for isolation efficiency of avian Influenza A Virus and Avian paramyxovirus serotype 1 from real-time reverse transcription polymerase chain reaction–positive wild bird surveillance samples

Virus isolation rates for influenza A virus (FLUAV) and Avian paramyxovirus serotype 1 (APMV-1) from wild bird surveillance samples are lower than molecular detection rates for the specific viral genomes. The current study was conducted to examine the possibility of increased virus isolation rates from real-time reverse transcription polymerase chain reaction (real-time RT-PCR) using alternative virus isolation substrates such as embryonating duck eggs (EDEs), embryonating turkey eggs (ETEs), Madin-Darby canine kidney (MDCK) cell cultures, and African green monkey kidney (Vero) cell cultures. Rectal swabs of birds in the orders Anseriformes and Charadriiformes were tested by real-time RT-PCR for the presence of FLUAV and APMV-1 genomes, and virus isolation (VI) was attempted on all real-time RT-PCR-positive samples. Samples with threshold cycle (Ct) ≤ 37 had VI rates for FLUAV of 62.5%, 50%, 43.8%, 31.5%, and 31.5% in embryonating chicken eggs (ECEs), ETEs, EDEs, MDCK cells, and Vero cells, respectively. A higher isolation rate was seen with ECEs compared to either cell culture method, but similar isolation rates were identified between the different embryonating avian eggs. Virus isolation rates for APMV-1 on samples with real-time RT-PCR Ct ≤ 37 were 75%, 100%, 100%, 0%, and 37.5% in ECEs, ETEs, EDEs, MDCK cells, and Vero cells, respectively. Significantly higher VI rates were seen with ECEs as compared to either cell culture method for all real-time RT-PCR-positive samples. Because of the limited availability and high cost of ETEs and EDEs, the data support the continuing usage of ECEs for primary isolation of both FLUAV and APMV-1 from real-time RT-PCR-positive wild bird surveillance samples.

Cytotoxic Effect of Combined Treatment with Ukrain and Methotrexate on Kidney Cells of Green Monkey

Abstract In in vitro study on green monkey kidney (GMK) cell culture, the cytotoxicity of Ukrain, methotrexate (MTX), and their combination was investigated. The effect of these drugs and their combination on viability (MTT test) and apoptosis of the cells was assessed. The IC10 and IC50 values for Ukrain and MTX were also indicated. After 24 h of incubation of GMK cells with Ukrain, IC10 amounted to 84.6 μmol/L and IC50 was 256.3 μmol/L, while MTX IC10 amounted to 7.18 μmol/L and IC50 was 154.8 μmol/l. After 24 h of simultaneous incubation of GMK cells with 50 μmol/L of Ukrain and 5.5 μmol/L of MTX, 15.33 % of cytotoxicity of the drugs in LDH test was found. The most significant increase in the cytotoxicity (42.10 %) was noted after 24 h incubation of GMK cells with 150 μmol/L of Ukrain and 5.5 μmol/L of MTX. Likewise, in the MTT assay the greatest decrease in the cells viability was found after incubation with 150 μmol/L of Ukrain and 5.5 μmol/L of MTX. The evaluation of apoptosis also indicated the adverse effect of combined application of both drugs on GMK cells.

Superiority of the buffy coat over serum or plasma for the detection of Alkhumra virus RNA using real time RT-PCR

RT-PCR to detect Alkhumra virus (ALKV) RNA in plasma or serum has been the standard practice to confirm this infection in the first seven days of illness. In this study, RT-PCR detection of viral RNA from the plasma, serum, and buffy coat (BC) was compared to virus isolation. Plasma, serum, and BC were obtained from seven patients with clinically suspected ALKV infection in Najran, Saudi Arabia. Baby hamster kidney (BHK-21) and rhesus monkey kidney (LLC-MK2) cell culture monolayers were used for virus isolation. Real-time RT-PCR was used to confirm ALKV infection and to detect viral RNA directly from plasma, serum, and BC. ALKV was isolated from five of the seven patients. The virus was isolated from all three specimen types (plasma, serum, and BC) of the five confirmed patients. ALKV RNA was detected directly by RT-PCR in BC in all five (100%) culture-positive patients and in plasma or serum in only four (80%) of the five patients. Three of the five patients for whom ALKV RNA was detected in BC also had detectable viral RNA in plasma and serum. In the remaining two patients with detectable ALKV RNA in the BC, the plasma was positive but the serum was negative in one patient, whereas the serum was positive and the plasma was negative in the other patient. The use of real-time RT-PCR to detect ALKV RNA in the BC was superior to using plasma and serum and equivalent to virus isolation.

Cell culture as a test system for toxicity.

Abstract Appropriate cell culture systems provide a useful additional method of screening for toxicity, in spite of the obvious problems of relating in vitro effects of test compounds at the cellular level to their effects in the whole animal. It is shown that a wide range of chemically disimilar molecules have a reversible inhibitory activity on the growth of primary cultures of monkey kidney cells. The potency of these compounds correlates with their lipid solubility, suggesting that the cell membranes may be their main site of action. Support for this is obtained by the correlation of inhibitory activity and the ability of the same compounds to stabilize the erythrocyte membrane against hypotonic haemolysis which is known to be a direct effect of interaction with the erythrocyte membrane. It is suggested that the ability of the food additive butylated hydroxytoluene to act as a potent inhibitor of cellular growth may account for its reported ability to prolong the life span of mice.

Simian Varicella Virus Induces Apoptosis in Monkey Kidney Cells by the Intrinsic Pathway and Involves Downregulation of Bcl-2 Expression

Simian varicella virus (SVV) causes varicella in primates, becomes latent in ganglionic neurons, and reactivates to produce zoster. SVV produces a cytopathic effect in monkey kidney cells in tissue culture. To study the mechanism by which SVV-infected cells die, we examined markers of apoptosis 24 to 64 h postinfection (hpi). Western blot analysis of virus-infected cell lysates revealed a significant increase in the levels of the cleaved active form of caspase-3, accompanied by a parallel increase in caspase-3 activity at 40 to 64 hpi. Caspase-9, a marker for the intrinsic pathway, was activated significantly in SVV-infected cells at all time points, whereas trace levels of the active form of caspase-8, an extrinsic pathway marker, was detected only at 64 hpi. Bcl-2 expression at the mRNA and protein levels was decreased by 50 to 70% throughout the course of virus infection. Release of cytochrome c, an activator of caspase-9, from mitochondria into the cytoplasm was increased by 200% at 64 hpi. Analysis of Vero cells infected with SVV expressing green fluorescent protein (SVV-GFP) at 64 hpi revealed colocalization of the active forms of caspase-3 and caspase-9 and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) staining with GFP. A significant decrease in the bcl-2 mRNA levels along with an abundance of mRNA specific for SVV genes 63, 40, and 21 was seen in the fraction of Vero cells that were infected with SVV-GFP. Together, these findings indicate that SVV induces apoptosis in cultured Vero cells through the intrinsic pathway in which Bcl-2 is downregulated.

Official Surveillance of Hepatitis A Virus: Description of an HAV Detection Method in Shellfish

Currently, hepatitis A virus (HAV) detection is not yet included in the regulation provided for food safety controls. However, the 2073/2005/EC regulation on microbiological criteria applied to food takes into account the sanitary issue as to viral contamination of food but postpones the definition of specific criteria for pathogenetic virus detection until reliable analytical methods are available. In this study, a PCR-based method for detection of HAV was subjected to a validation process in order to describe its performance and to check its reliability for shellfish monitoring. Shellfish were processed for virus recovery through PEG8000-mediated sedimentation. Viral RNA extraction was carried out with a commercial kit and extracted RNA was then subjected to a reverse transcriptase heminested PCR (rt-heminested PCR). Foetal rhesus monkey kidney (FRhK4) cell culture infected with HAV worked as positive control in the assay: so, also supernatant from infected FRhK4 cells was subjected to a parallel validation process, starting to RNA extraction. The validation process was carried out by establishing qualitative and semi-quantitative parameters concerning accuracy, precision, analytical specificity and sensitivity (limit of detection, LOD), robustness and stability. The HAV detection method for shellfish and supernatant from infected FRhK4 cells showed 100% accuracy and precision. It has proved robust and stable; the LOD of rt-heminested PCR was estimated as nine genomic copies of DNA target. The validation process has objectively demonstrated that the HAV detection method on shellfish has good performance, so it might be applied with enough reliability in food safety official controls.

In vitro inhibitory activity of EDTA against planktonic and adherent cells ofCandida sp.

Candida sp. can cause infections of indwelling medical devices associated with biofilm formation, which are difficult to treat due to insensitivity of adherent microorganisms to host defence mechanisms and standard antimicrobial therapy. The aim of this paper was to determine the effect of EDTA (disodium salt) on the adhesion ofCandida sp. to some catheters and also on biofilm formation by the yeasts and its eradication in relation to cytotoxicity of this chelating agent to the cell cultures. The adhesion process and biofilm formation, and also EDTA cytotoxicity to green monkey kidney (GMK) cell culture were determined using MTT tetrazolium salt [3-(4,5-dimethylthiazol-2-yl) −2,5-diphenyltetrazolium bromide)] reduction assay. EDTA inhibited the growth of free-floating forms ofCandida sp. strains with minimal inhibitory concentration (MIC) from 0.06 to 0.25 mM; the minimal fungicidal concentration (MFC) values ranged from 64 to 128 mM. The prevention ofCandida sp. adhesion on the catheters used or eradication of the adherent cells was achieved at 0.5 to 4.0 mM EDTA. Also biofilm formation was prevented by 0.5 to 4.0 mM EDTA. Much higher concentration of EDTA (32 to 128 mM) was needed to eradicate the mature biofilm. EDTA at concentration up to 1 mM was not toxic for GMK cells. At higher concentration, toxicity of EDTA to GMK cells was correlated with the concentration of this agent and the time of exposure. Summing up, EDTA may be regarded as a useful agent rather in prophylaxis of candidal infections of medical devices.

Physiological activity and tissue distribution of a perchlorate‐sensitive iodide transport protein from anuran amphibians

Iodide is a critical trace nutrient in the synthesis of thyroid hormone (TH). Environmental contaminants that competitively inhibit the sodium/iodide symporter (NIS), such as ammonium perchlorate and sodium chlorate, may pose a significant threat to developing amphibians, which require TH for metamorphosis and reproductive development. Unfortunately, little is known about the structure and regulation of the frog NIS. We transiently transfected cultured monkey kidney cells with a putative iodide transporter cloned from African clawed frogs (Xenopus laevis), the X. laevis solute carrier family 5 (sodium iodide symporter) member 5 (SLC5A5), and measured radiolabeled 125I uptake in vitro. Cells expressing the SLC5A5 clone had significantly greater 125I than sham-transfected control cells. Uptake of 125I in SCL5A5-transfected cells was significantly inhibited in the presence of perchlorate. Amplification of RNA sequences from amphibian tissues indicates that the SCL5A5 is expressed in thyroid gland, stomach and kidney of larval bullfrogs (Rana catesbeiana) and larval X. laevis, tissues known to transport iodide. We conclude that the X. laevis SLC5A5 transporter is a perchlorate-sensitive iodide transporter that is expressed in thyroid and extrathyroid tissues in frogs. This research lays the groundwork for future studies examining the physiology and toxicology of iodide transport in amphibian thyroid and non-thyroid epithelia. [Supported by NIH grant RR-19799.]

Poliovirus vaccine strains in sewage and river water in South Africa

Since the initiation of the global poliomyelitis eradication program in 1988, the number of wild-type polio cases decreased from 350,000 to fewer than 500, and the number of polio endemic countries declined from more than 125 to 10. The last case of polio in South Africa caused by a wild-type poliovirus (PV) occurred in 1989. The live attenuated oral poliovirus vaccine (OPV) has been effectively used in the reduction and control of poliomyelitis. However, as OPV strains are excreted in stools after vaccination, this vaccine could become a source of dissemination of PVs in the environment and the potential cause of poliomyelitis. Therefore, the aim of the study was to determine the occurrence of OPV strains in selected sewage and river water samples. During the period between 2001 and 2003, 138 samples of river water and 213 samples of settled sewage were collected from selected areas of South Africa. A total of 860 plaques were analysed, which consisted of 703 plaques from the sewage and 157 plaques from the river water samples. Using a reverse transcriptase (RT)-multiplex PCR, 49 PVs were successfully distinguished from 176 non-polio enteroviruses (NPEVs). The 176 NPEVs consisted of 50 coxsackie B2 viruses (CBV2), followed by 39 echoviruses 11 (ECV11), 25 CBV5, 21 CBV3, 15 CBV4, 14 coxsackie A6 viruses (CAV6), 7 CBV6, 2 CAV5, 2 CBV1, and 1 ECV19, which was in agreement with the prevalence of these EVs in other parts of the world. The Sabin-specific RT-triplex PCR revealed the presence of 29 Sabin PV type 1, 8 Sabin PV type 2, and 12 Sabin PV type 3 isolates. Buffalo green monkey kidney and primary liver carcinoma cell cultures allowed the amplification of a broad spectrum of EVs, whereas human epidermoid carcinoma cells were more selective for PVs. This study addressed some of the issues regarding the prevalence of OPV strains in the environment. The identification of 49 viable OPV isolates confirmed the presence and circulation of PV vaccine strains in sewage and river water. The extent of the potential health risk constituted by these OPV isolates remains to be investigated.

Viruses from Nonhuman Primates

To the Editor: I read with interest the article by Jones-Engel et al. (1), which described the frequency of viruses infecting temple rhesus macaques. The investigation included the polyomavirus simian virus 40 (SV40), a pathogen recognized to have infected millions of humans who were vaccinated with polio vaccines produced in cultures of rhesus monkey kidney cells (2,3). The authors indicated that technologic advances have improved the specificity of detecting SV40 antibodies and used an enzyme immunoassay based on viruslike particles (VLPs) to perform the analysis (1). However, the specificity of the SV40 enzyme immunoassay is problematic because studies with serum samples from macaques have found that antibodies are cross-reactive with polyomaviruses JCV and BKV (4). In addition, in monkey sera SV40 VLPs correlated with BKV antibodies. Similar conflicting results have been found in human studies that used polyomavirus VLPs assays (3). These limitations are the result of polyomavirus VLPs assays using expression of the VP1 capsid protein (4), a highly homologous gene among JCV, BKV, and SV40 (3). In contrast, modern molecular biology assays are the preferred method for the analysis of SV40 infections (2,3). In addition, these sensitive and specific techniques can provide insights into the distribution of SV40 strains and variants (2,3). This is important because recent data suggest that the biological properties of SV40 strains vary in vivo (5). Because current evidence shows that SV40 infections are identified in some humans and that the virus is associated with selected human malignancies (2,3), prospective longitudinal studies that use molecular techniques are needed to examine the prevalence and ecology of SV40. The Institute of Medicine recognizes that the biologic evidence indicates that infections with this DNA virus could lead to cancer in humans and recommends targeted biologic research of SV40 in human populations (2).

Tabebuia avellanedae naphthoquinones: activity against methicillin-resistant staphylococcal strains, cytotoxic activity and in vivo dermal irritability analysis

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococcus infections are a worldwide concern. Currently, these isolates have also shown resistance to vancomycin, the last therapy used in these cases. It has been observed that quinones and other related compounds exhibit antibacterial activity. This study evaluated the antibacterial activity, toxicity and in vivo dermal irritability of lapachol extracted from Tabebuia avellanedae and derivatives against methicillin-resistant staphylococcal isolates. In addition, its mechanism of action was also analyzed.MethodsThe compounds β-lapachone, 3-hydroxy β N lapachone and α-lapachone were tested to determine the MIC values against methicillin-resistant S. aureus, S. epidermidis and S. haemolyticus strains, being the two last ones hetero-resistant to vancomycin. Experiments of protein synthesis analysis to investigate the naphthoquinones action were assessed. In vitro toxicity to eukaryotic BSC-40 African Green Monkey Kidney cell cultures and in vivo primary dermal irritability in healthy rabbits were also performed.ResultsThe compounds tested showed antibacterial activity (MICs of 8, 4/8 and 64/128 μg/mL to β-lapachone, 3-hydroxy β N lapachone and α-lapachone, respectively), but no bactericidal activity was observed (MBC > 512 μg/mL for all compounds). Although it has been observed toxic effect in eukaryotic cells, the compounds were shown to be atoxic when applied as topic preparations in healthy rabbits. No inhibition of proteins synthesis was observed.ConclusionOur results suggest that quinones could be used in topic preparations against wound infections caused by staphylococci, after major investigation of the pharmacological properties of the compounds. Studies about the use of these compounds on tumoral cells could be carried on, due to their effect in eukaryotic cells metabolism.