Echovirus type 30 infection associated with aseptic meningitis in Nassau County, New York, USA

A Coxsackie B4 virus isolated in Yunnan in 2009 is a recombinant

Coxsackievirus B4 is a member of the species Enterovirus B in the Enterovirus genus of the Picornaviridae family. So far, there are only seven complete genome sequences of CVB4 published in GenBank database. In the study, the complete genome analysis of a Coxsackievirus B4 strain A155/YN/CHN/2009 isolated from a child with aseptic meningitis in Yunnan Province was performed. It had 85.1 and 83.3 % nucleotide similarity with prototype strain J.V.B Benschoten in the VP1 region and the complete genome, respectively. Phylogenetic analysis of VP1 region showed that A155/YN/CHN/2009 belongs to Genotype V circulating only in mainland of China. The results of Simplot and Bootscanning analysis implicated that A155 has recombined with other HEV-B viruses.

Evaluation of two (semi-)nested VP1 based-PCRs for typing enteroviruses directly from cerebral spinal fluid samples

Human enteroviruses (EVs) are the leading cause of CNS-associated disease in childhood. Identification of the EV types that patients are infected with is essential for monitoring outbreaks, the emergence of new types or variants, epidemiological surveillance and contributes to patient management. Rapid and sensitive molecular detection methods are frequently used to detect EVs/HPeVs directly from CSF. This requires that sensitive EV typing methods from CSF material need to be developed. In the present study two nested PCR-based typing assays were evaluated. The performance of the EV-A and -B specific nested PCR protocol and the Codehop-based PCR protocol were analyzed with several TCID(50)-titrated EV-A to D strains and 22 EV positive CSF samples. The EV-A and -B protocol was found to be more sensitive than the Codehop protocol. The Codehop protocol showed a high degree of aspecific amplification products when run on a gel, and required additional gel purification. The detection limit of the two protocols varied between the types, ranging from 0.1TCID(50)/mL sample to 10(6)TCID(50)/mL sample. From the 22 EV positive CSF samples, 15 (68%) samples were typed using either protocol. All samples were characterized as members of species B (E30 (9), CAV9 (2), E6 (1), E11 (1), E21 (1), E25 (1)). Three samples (E30 (2) and E25 (1)) could only be typed using the EV-B protocol. In this study, selected EV strains could be typed using both assays at low virus concentrations, typically found in CSF. However, the EV-A and -B protocol was more sensitive than the Codehop protocol for primary typing of CSF samples.

Prospective investigation of a large outbreak of meningitis due to echovirus 30 during summer 2000 in marseilles, france

Enteroviruses (EVs) are responsible for an array of clinical diseases affecting different systems of the organism. Many cases are asymptomatic; the most severe clinical syndromes caused by EVs are due to infection of the central nervous system and present as aseptic meningitis or encephalitis. We report here a large outbreak of enteroviral meningitis that spread in Marseilles, France, during the year 2000. The dominant strain of the outbreak was genetically identified as a human echovirus 30. The study was conducted prospectively from May to December 2000, with an investigative protocol recording epidemiologic, clinical, and laboratory data. A total of 250 patients with febrile neurologic manifestations were included between May 15 and December 30, 2000. A total of 195 cerebrospinal fluid (CSF) samples, 114 throat swabs, and 85 stool specimens were processed through viral culture and resulted in respectively 117 (60%), 61 (54%), and 58 (68%) cultures positive for EV; 69/106 (65%) CSF samples tested positive for the presence of EV RNA. None of the throat swab cultures but 5 of the stool cultures in control patients were positive. One hundred thirty-nine (55.6%) patients were considered confirmed cases because they had positive culture or reverse transcription polymerase chain reaction (RT-PCR) in CSF, and 38 (15.2%) patients were considered probable cases because they had a positive throat and/or stool culture and a negative (or not performed) procedure in CSF. The 177 confirmed and probable cases were not significantly different from the remaining 73 patients in terms of age distribution and epidemiologic, clinical, and biologic characteristics. The median age was 18.4 years (range, 15 d to 84 yr), and 92% of patients were younger than 40 years old. The male:female sex ratio was 1.8:1. We found no evidence of cases spread in nosocomial, household, or institutional settings, or limited community spread. All patients were immunocompetent except 4 adults. Meningoencephalitis represented 5.6% of cases. All but 3 of the 177 patients had a good outcome without sequelae. Two immunocompetent adults with meningoencephalitis had neurologic sequelae and an immunosuppressed adult had a fatal outcome. Upper respiratory symptoms were noted in 18.5% of patients, diarrhea in 11.5%, various types of rash in 4.5%, and myalgia in 3.8%. In CSF, white cell count was elevated in 90% of cases, with a percentage of neutrophils >50% in 55% of cases. Protein level was increased in 43% of cases. In blood, C-reactive protein was elevated in 67% of cases. Other blood parameters were unremarkable. Clinical and laboratory features did not differ from those related to other pathogens that caused meningitis and meningoencephalitis. Hence, unnecessary treatment for other infections is frequently instituted during EV infections. Virologic diagnosis is important to distinguish between EV and other treatable bacterial and viral diseases.

Identification of enteroviruses by using monoclonal antibodies against a putative common epitope

A common epitope region of enteroviruses was identified by sequence-independent single-primer amplification (SISPA), followed by immunoscreening of 11 cDNA libraries from two Korean enterovirus isolates (echoviruses 7 and 30) and a coxsackievirus B3 (ATCC-VR 30). The putative common epitope region was localized in the N terminus of VP1 when the displayed recombinant proteins from the phages were chased by the convalescent-phase sera. The genomic region encoding the common epitope region was amplified and then expressed by using the vector pGEX-5X-1. The antigenicity of the expressed recombinant protein was identified by Western blotting with guinea pig antisera for six different serotypes of enteroviruses. After successive immunization of mice with the recombinant common epitope protein, splenocytes were extracted and hybridized with P3X63-Ag8-653 cells. A total of 24 hybridomas that produced monoclonal antibodies (MAbs) against the putative common epitope of enteroviruses were selected. Four of these were immunoglobulin G1 isotypes with a kappa light chain. These MAbs recognized 15 Korean endemic serotypes and prototypes of enteroviruses in an indirect immunofluorescence assay. These results suggest that the expressed protein might be a useful antigen for producing group common antibodies and that the use of the MAbs against the putative common epitope of enteroviruses might be a valuable diagnostic tool for rapidly identifying a broad range of enteroviruses.

Genetic diversity of echovirus 30 during a meningitis outbreak, demonstrated by direct molecular typing from cerebrospinal fluid

Echovirus 30 is one of the enterovirus serotypes isolated most frequently in meningitis cases. The genetic diversity of echovirus 30 was investigated in patients hospitalised during an outbreak in 2000 in Clermont-Ferrand, France. A nested reverse transcription-PCR (RT-PCR) assay was developed for qualitative analysis of the echovirus 30 VP1 encoding sequence directly from cerebrospinal fluid. The viral sequences obtained for 22 patients were compared with those of virus isolates obtained from nine patients with echovirus 30 meningitis admitted to hospital in 1996-1997 and with echovirus 30 sequences from international databases. In 2000, meningitis cases were caused by two virus variants (C3 and C4) distinct genetically from the other two variants (C1 and C2) identified during the period 1996-1997. A detailed phylogenetic analysis established that the C1, C2, and C3 variants had close relatives among viruses previously identified in other geographical areas. The C4 variant had not been described earlier. The genomic differences observed between the four echovirus 30 variants arose at synonymous sites indicating that the viruses shared similar antigenic sites in the VP1 encoding sequence. Overall, these observations suggest wide circulation of different echovirus 30 variants and periodic importation of new viruses. The apparent displacement observed between virus variants did not result from a selective advantage caused by antigenic variation.

Nosocomial transmission of echovirus 30: molecular evidence by phylogenetic analysis of the VP1 encoding sequence

We investigated six cases of enterovirus infection in a neonatal unit. The index patient, a 5-day-old boy, was admitted with aseptic meningitis due to echovirus 30 (E30). Secondary infections with E30 occurred in five babies. Comparison of the complete VP1 sequences showed that the isolates recovered from the index patient and his mother were closely related to those recovered from the five babies with secondary infections, demonstrating a nosocomial transmission of the virus. In the phylogenetic tree reconstructed from the VP1 sequences, the isolates formed a monophyletic cluster related to an E30 strain collected in June 1997 during an outbreak of aseptic meningitis.

Genomic variations in echovirus 30 persistent isolates recovered from a chronically infected immunodeficient child and comparison with the reference strain

Seven sequential isolates of echovirus type 30 (EV30) were recovered over 22 months from a child with severe combined immune deficiency syndrome. The nucleotide sequences of the 5' halves of the genomes (4,400 nucleotides) of the first (S1) and last (S7) isolates were determined and compared with that of the EV30 Bastianni reference strain, also determined in this study. In genome regions P1 and P2, 101 variations were identified between the two isolates. Synonymous differences far outnumbered nonsynonymous differences. Amino acid changes affected both capsid and nonstructural polypeptides (particularly 2B). The VP1 nucleotide sequences of the seven isolates were determined to analyze genome evolution during the chronic infection. In the phylogenetic tree, the seven isolates were directly related to the prototype strain in an individual monophyletic group, strongly suggesting that the chronic infection in the child arose from a single persistent EV30 isolate. Four lineages were observed in the persistent isolates. Isolates S2, S4, S5, and S6 were close relatives of one another, whereas isolates S1 and S3 formed individual lineages. Isolate S7, distantly related to all other isolates, formed the fourth lineage. These findings suggest the quasispecies nature of the genomes of the seven sequential EV30 isolates. Grouping of persistent isolates on the basis of replicative capacities was consistent with phylogenetic relationships. Overall, the results indicate that genetically related EV30 variants with different replicative capacities coexisted in a carrier state, probably in the gastrointestinal tract, during the infection of the child.

Intratypic genome variability of echovirus type 30 in part of the VP4/VP2 coding region

The genetic relationship of 33 echovirus type 30 (E30) isolates associated with three different outbreaks of meningitis in Norway and one outbreak in USA was assessed using direct sequencing of amplicons derived from a region covering part of the capsid proteins VP4 and VP2. The E30 sequences were compared to each other, and to other enteroviruses. Less sequence variation was observed between the isolates from a single outbreak (2-3%) than between groups of isolates from different outbreaks (4-9%). All observed nucleotide substitutions were amino acid silent. Homology between enteroviruses obtained from GenEMBL and the nucleotide consensus sequence generated from the E30 isolates varied between 44.8% (coxsackievirus A24) and 72.6% (coxsackievirus A9). Comparing the E30 sequences in this part of the genome with other enteroviruses, E30 clearly belongs to the coxsackie B-like virus group.

Sequence comparison of echovirus type 30 isolates to other enteroviruses in the 5'noncoding region

The genetic relationship between echovirus type 30 (E30) isolates were characterised by means of amplification of a part of the 5'noncoding region by polymerase chain reaction and direct sequencing. Later, the E30 sequences were compared with other enteroviruses. Homology between recent clinical E30 isolates from different years exceeds 98% at the nucleotide level. Comparing the E30 sequence with other enteroviruses, homology varied between 68% (coxsackievirus A24) and 93% (coxsackievirus B3). E30 appeared to have coxsackie B-like characteristics in this genomic part. It is considered that E30 and coxsackie B viruses belong to the same enterovirus subgroup.