Construction and characterization of a saturated Tn-seq library of Salmonella Typhimurium ATCC 14028

Salmonella enterica is an important foodborne pathogen. Here, we present the construction and characterization of a high-density transposon sequencing library of the Salmonella Typhimurium ATCC 14028 strain. Essential, advantageous, and disadvantageous genes for growth in rich culture medium were identified on the chromosome and the pSLT plasmid.

Lipopolysaccharide core type diversity in the Escherichia coli species in association with phylogeny, virulence gene repertoire and distribution of type VI secretion systems

Escherichia coli is a very versatile species for which diversity has been explored from various perspectives highlighting, for example, phylogenetic groupings and pathovars, as well as a wide range of O serotypes. The highly variable O-antigen, the most external part of the lipopolysaccharide (LPS) component of the outer membrane of E. coli, is linked to the innermost lipid A through the core region of LPS of which five different structures, denominated K-12, R1, R2, R3 and R4, have been characterized so far. The aim of the present study was to analyse the prevalence of these LPS core types in the E. coli species and explore their distribution in the different E. coli phylogenetic groups and in relationship with the virulence gene repertoire. Results indicated an uneven distribution of core types between the different phylogroups, with phylogroup A strains being the most diverse in terms of LPS core types, while phylogroups B1, D and E strains were dominated by the R3 type, and phylogroups B2 and C strains were dominated by the R1 type. Strains carrying the LEE virulence operon were mostly of the R3 type whatever the phylogroup while, within phylogroup B2, strains carrying a K-12 core all belonged to the complex STc131, one of the major clones of extraintestinal pathogenic E. coli (ExPEC) strains. The origin of this uneven distribution is discussed but remains to be fully explained, as well as the consequences of carrying a specific core type on the wider aspects of bacterial phenotype.

Whole-Genome Analysis of Mycobacterium avium subsp. paratuberculosis IS900 -

Mycobacterium avium subsp. paratuberculosis (Map) is the etiological agent of Johne’s disease in ruminants. The IS900 insertion sequence (IS) has been used widely as an epidemiological marker and target for PCR diagnosis. Updated DNA sequencing technologies have led to a rapid increase in available Map genomes, which makes it possible to analyze the distribution of IS900 in this slow-growing bacterium. The objective of this study is to characterize the distribution of the IS900 element and how it affects genomic evolution and gene function of Map. A secondary goal is to develop automated in silico restriction fragment length polymorphism (RFLP) analysis using IS900. Complete genomes from the major phylogenetic lineages known as C-type and S-type (including subtypes I and III), were chosen to represent the genetic diversity of Map. IS900 elements were located in these genomes using BLAST software and the relevant fragments extracted. An in silico RFLP analysis using the BstEII restriction site was performed to obtain exact sizes of the DNA fragments carrying a copy of IS900 and the resulting RFLP profiles were analyzed and compared by digital visualization of the separated restriction fragments. The program developed for this study allowed automated localization of IS900 sequences to identify their position within each genome along with the exact number of copies per genome. The number of IS900 copies ranged from 16 in the C-type isolate to 22 in the S-type subtype I isolate. A loci-by-loci sequence alignment of all IS900 copies within the three genomes revealed new sequence polymorphisms that define three sequevars distinguishing the subtypes. Nine IS900 insertion site locations were conserved across all genomes studied while smaller subsets were unique to a particular lineage. Preferential insertion motif sequences were identified for IS900 along with genes bordering all IS900 insertions. Rarely did IS900 insert within coding sequences as only three genes were disrupted in this way. This study makes it possible to automate IS900 distribution in Map genomes to enrich knowledge on the distribution dynamics of this IS for epidemiological purposes, for understanding Map evolution and for studying the biological implications of IS900 insertions.

Engineering Synthetic Lipopeptide Antigen for Specific Detection of Mycobacterium avium subsp. paratuberculosis Infection

Unlike other MAC members, Mycobacterium avium subsp. paratuberculosis (MAP) does not produce glycopeptidolipids (GPL) on the surface of the cell wall but a lipopentapeptide called L5P (also termed Lipopeptide-I or Para-LP-01) characterized in C-type (bovine) strains. This lipopeptide antigen contains a pentapeptide core, D-Phenylalanine-N-methyl-L-Valine-L-Isoleucine-L-Phenylalanine-L-Alanine, in which the N-terminal D-Phenylalanine is amido-linked with a fatty acid (C18–C20). The molecular and genetic characterization of this antigen demonstrated that L5P is unique to MAP. Knowledge of the structure of L5P enabled synthetic production of this lipopeptide in large quantities for immunological evaluation. Various studies described the immune response directed against L5P and confirmed its capability for detection of MAP infection. However, the hydrophobic nature of lipopeptide antigens make their handling and use in organic solvents unsuitable for industrial processes. The objectives of this study were to produce, by chemical synthesis, a water-soluble variant of L5P and to evaluate these compounds for the serological diagnosis of MAP using well-defined serum banks. The native L5P antigen and its hydrosoluble analog were synthesized on solid phase. The pure compounds were evaluated on collections of extensively characterized sera from infected and non-infected cattle. ROC analysis showed that L5P and also its water-soluble derivative are suitable for the development of a serological test for Johne's disease at a population level. However, these compounds used alone in ELISA have lower sensitivity (Se 82% for L5P and Se 62% for the water-soluble variant of L5P) compared to the Se 98% of a commercial test. Advantageously, these pure synthetic MAP specific antigens can be easily produced in non-limiting quantities at low cost and in standardized batches for robust studies. The fact that L5P has not been validated in the context of ovine paratuberculosis highlights the need to better characterize the antigens expressed from the different genetic lineages of MAP to discover new diagnostic antigens. In the context of infections due to other mycobacteria such as M. bovis or the more closely related species M. avium subsp. hominissuis, the L5P did not cross react and therefore may be a valuable antigen to solve ambiguous results in other tests.

Engineering Synthetic Lipopeptide Antigen for Specific Detection of Mycobacterium avium subsp. paratuberculosis Infection

Unlike other MAC members, Mycobacterium avium subsp. paratuberculosis (MAP) does not produce glycopeptidolipids (GPL) on the surface of the cell wall but a lipopentapeptide called L5P (also termed Lipopeptide-I or Para-LP-01) characterized in C-type (bovine) strains. This lipopeptide antigen contains a pentapeptide core, D-Phenylalanine-N-methyl-L-Valine-L-Isoleucine-L-Phenylalanine-L-Alanine, in which the N-terminal D-Phenylalanine is amido-linked with a fatty acid (C18–C20). The molecular and genetic characterization of this antigen demonstrated that L5P is unique to MAP. Knowledge of the structure of L5P enabled synthetic production of this lipopeptide in large quantities for immunological evaluation. Various studies described the immune response directed against L5P and confirmed its capability for detection of MAP infection. However, the hydrophobic nature of lipopeptide antigens make their handling and use in organic solvents unsuitable for industrial processes. The objectives of this study were to produce, by chemical synthesis, a water-soluble variant of L5P and to evaluate these compounds for the serological diagnosis of MAP using well-defined serum banks. The native L5P antigen and its hydrosoluble analog were synthesized on solid phase. The pure compounds were evaluated on collections of extensively characterized sera from infected and non-infected cattle. ROC analysis showed that L5P and also its water-soluble derivative are suitable for the development of a serological test for Johne's disease at a population level. However, these compounds used alone in ELISA have lower sensitivity (Se 82% for L5P and Se 62% for the water-soluble variant of L5P) compared to the Se 98% of a commercial test. Advantageously, these pure synthetic MAP specific antigens can be easily produced in non-limiting quantities at low cost and in standardized batches for robust studies. The fact that L5P has not been validated in the context of ovine paratuberculosis highlights the need to better characterize the antigens expressed from the different genetic lineages of MAP to discover new diagnostic antigens. In the context of infections due to other mycobacteria such as M. bovis or the more closely related species M. avium subsp. hominissuis, the L5P did not cross react and therefore may be a valuable antigen to solve ambiguous results in other tests.

Engineering Synthetic Lipopeptide Antigen for Specific Detection of Mycobacterium avium subsp. paratuberculosis Infection

Unlike other MAC members, Mycobacterium avium subsp. paratuberculosis (MAP) does not produce glycopeptidolipids (GPL) on the surface of the cell wall but a lipopentapeptide called L5P (also termed Lipopeptide-I or Para-LP-01) characterized in C-type (bovine) strains. This lipopeptide antigen contains a pentapeptide core, D-Phenylalanine-N-methyl-L-Valine-L-Isoleucine-L-Phenylalanine-L-Alanine, in which the N-terminal D-Phenylalanine is amido-linked with a fatty acid (C18-C20). The molecular and genetic characterization of this antigen demonstrated that L5P is unique to MAP. Knowledge of the structure of L5P enabled synthetic production of this lipopeptide in large quantities for immunological evaluation. Various studies described the immune response directed against L5P and confirmed its capability for detection of MAP infection. However, the hydrophobic nature of lipopeptide antigens make their handling and use in organic solvents unsuitable for industrial processes. The objectives of this study were to produce, by chemical synthesis, a water-soluble variant of L5P and to evaluate these compounds for the serological diagnosis of MAP using well-defined serum banks. The native L5P antigen and its hydrosoluble analog were synthesized on solid phase. The pure compounds were evaluated on collections of extensively characterized sera from infected and non-infected cattle. ROC analysis showed that L5P and also its water-soluble derivative are suitable for the development of a serological test for Johne's disease at a population level. However, these compounds used alone in ELISA have lower sensitivity (Se 82% for L5P and Se 62% for the water-soluble variant of L5P) compared to the Se 98% of a commercial test. Advantageously, these pure synthetic MAP specific antigens can be easily produced in non-limiting quantities at low cost and in standardized batches for robust studies. The fact that L5P has not been validated in the context of ovine paratuberculosis highlights the need to better characterize the antigens expressed from the different genetic lineages of MAP to discover new diagnostic antigens. In the context of infections due to other mycobacteria such as M. bovis or the more closely related species M. avium subsp. hominissuis, the L5P did not cross react and therefore may be a valuable antigen to solve ambiguous results in other tests.

Genetic Diversity Among Mycobacterium avium Subspecies Revealed by Analysis of Complete Genome Sequences

Mycobacterium avium comprises four subspecies that contain both human and veterinary pathogens. At the inception of this study, twenty-eight M. avium genomes had been annotated as RefSeq genomes, facilitating direct comparisons. These genomes represent strains from around the world and provided a unique opportunity to examine genome dynamics in this species. Each genome was confirmed to be classified correctly based on SNP genotyping, nucleotide identity and presence/absence of repetitive elements or other typing methods. The Mycobacterium avium subspecies paratuberculosis (Map) genome size and organization was remarkably consistent, averaging 4.8 Mb with a variance of only 29.6 kb among the 13 strains. Comparing recombination events along with the larger genome size and variance observed among Mycobacterium avium subspecies avium (Maa) and Mycobacterium avium subspecies hominissuis (Mah) strains (collectively termed non-Map) suggests horizontal gene transfer occurs in non-Map, but not in Map strains. Overall, M. avium subspecies could be divided into two major sub-divisions, with the Map type II (bovine strains) clustering tightly on one end of a phylogenetic spectrum and Mah strains clustering more loosely together on the other end. The most evolutionarily distinct Map strain was an ovine strain, designated Telford, which had >1,000 SNPs and showed large rearrangements compared to the bovine type II strains. The Telford strain clustered with Maa strains as an intermediate between Map type II and Mah. SNP analysis and genome organization analyses repeatedly demonstrated the conserved nature of Map versus the mosaic nature of non-Map M. avium strains. Finally, core and pangenomes were developed for Map and non-Map strains. A total of 80% Map genes belonged to the Map core genome, while only 40% of non-Map genes belonged to the non-Map core genome. These genomes provide a more complete and detailed comparison of these subspecies strains as well as a blueprint for how genetic diversity originated.

The complete genome sequence of Mycobacterium bovis Mb3601, a SB0120 spoligotype strain representative of a new clonal group

Mycobacterium bovis strain Mb3601 was isolated from the lymph node of an infected bovine in a bovine tuberculosis highly enzoonotic area of Burgundy, France. It was selected to obtain a complete genome for a new clonal complex, mainly constituted by SB0120-spoligotype strains that we propose to name "European 3". It was recently described as "clonal group I" based on whole-genome SNP analysis of 87 French strains. Here we describe the 4,365,068 bp complete genome obtained by the combination of PacBio and Illumina technologies. This genome of 65.64% G + C content includes 4024 predicted protein-coding genes, 52 tRNA, 3 rRNA and 11 copies of IS6110.

MAC-INMV-SSR: a web application dedicated to genotyping members of Mycobacterium avium complex (MAC) including Mycobacterium avium subsp. paratuberculosis strains

Genotyping of Mycobacterium avium subsp. paratuberculosis (Map) is an indispensable tool for surveillance of this significant veterinary pathogen. For Map, multi-locus variable number tandem repeat analysis (MLVA) targeting mycobacterial interspersed repetitive units (MIRUs) and other variable number variable-number tandem repeats (VNTRs) was established using 8 markers. In the recent past this standard, portable, reproducible and discriminatory typing method has been frequently applied alone or in combinations with multi-locus short-sequence-repeat (MLSSR) sequencing. With the widespread use of these genotyping methods, standardization between laboratories needs to be managed, and knowledge of existing profiles and newly defined genotypes should be indexed and shared. To meet this need, a web application called "MAC-INMV-SSR database" was developed. This freely accessible service allows users to compare MLVA and MLSSR subtype data of their strains with those of existing reference strains analyzed with the same genotyping methods.

Accurate Phylogenetic Relationships Among Mycobacterium bovis Strains Circulating in France Based on Whole Genome Sequencing and Single Nucleotide Polymorphism Analysis

In recent years the diversity of the French Mycobacterium bovis population responsible for bovine tuberculosis (bTB) outbreaks since 1970 has been described in detail. To further understand bTB evolution in France, we used single nucleotide polymorphisms (SNPs) based on whole genome sequence versus classical genotyping methods in order to identify accurate phylogenetic relationships between M. bovis strains. Whole genome sequencing was carried out on a selection of 87 strains which reflect the French M. bovis population’s genetic diversity. Sequences were compared to the M. bovis reference genome AF2122/97. Comparison among the 87 genomes revealed 9,170 sites where at least one strain shows a SNP with respect to the reference genome; 1,172 are intergenic and 7,998 in coding sequences, of which 2,880 are synonymous and 5,118 non-synonymous. SNP-based phylogenetic analysis using these 9,170 SNP is congruent with the cluster defined by spoligotyping and multilocus variable number of tandem repeat analysis typing. In addition, some SNPs were identified as specific to genotypic groups. These findings suggest new SNP targets that can be used for the development of high-resolving methods for genotyping as well as for studying M. bovis evolution and transmission patterns. The detection of non-synonymous SNPs on virulence genes enabled us to distinguish different clusters. Our results seem to indicate that genetically differentiated clusters could also display distinctive phenotypic traits.

Environmental Mycobacterium avium subsp. paratuberculosis Hosted by Free-Living Amoebae

Mycobacterium avium subsp. paratuberculosis is responsible for paratuberculosis in animals. This disease, leading to an inflammation of the gastrointestinal tract, has a high impact on animal health and an important economic burden. The environmental life cycle of M. avium subsp. paratuberculosis is poorly understood and several studies suggest that free-living amoebae (FLA) might be a potential environmental host. FLA are protozoa found in water and soil that are described as reservoirs of pathogenic and non-pathogenic bacteria in the environment. Indeed, bacteria able to survive within these amoebae would survive phagocytosis from immune cells. In this study, we assessed the in vitro interactions between several strains of M. avium subsp. paratuberculosis and Acanthamoeba castellanii. The results indicate that the bacteria were able to grow within the amoeba and that they can survive for several days within their host. To explore the presence of M. avium subsp. paratuberculosis in environmental amoebae, we sampled water from farms positive for paratuberculosis. A M. avium subsp. paratuberculosis strain was detected within an environmental amoeba identified as related to the poorly described Rosculus genus. The bacterial strain was genotyped, showing that it was similar to previous infectious strains isolated from cattle. In conclusion, we described that various M. avium subsp. paratuberculosis strains were able to grow within amoebae and that these bacteria could be found on farm within amoebae isolated from the cattle environment. It validates that infected amoebae might be a reservoir and vector for the transmission of M. avium subsp. paratuberculosis.

Cell wall peptidolipids of Mycobacterium avium: from genetic prediction to exact structure of a nonribosomal peptide

Mycobacteria have a complex cell wall structure that includes many lipids; however, even within a single subspecies of Mycobacterium avium these lipids can differ. Total lipids from an M. avium subsp. paratuberculosis (Map) ovine strain (S-type) contained no identifiable glycopeptidolipids or lipopentapeptide (L5P), yet both lipids are present in other M. avium subspecies. We determined the genetic and phenotypic basis for this difference using sequence analysis as well as biochemical and physico-chemical approaches. This strategy showed that a nonribosomal peptide synthase, encoded by mps1, contains three amino acid specifying modules in ovine strains, compared to five modules in bovine strains (C-type). Sequence analysis predicted these modules would produce the tripeptide Phe-N-Methyl-Val-Ala with a lipid moiety, termed lipotripeptide (L3P). Comprehensive physico-chemical analysis of Map S397 extracts confirmed the structural formula of the native L3P as D-Phe-N-Methyl-L-Val-L-Ala-OMe attached in N-ter to a 20-carbon fatty acid chain. These data demonstrate that S-type strains, which are more adapted in sheep, produce a unique lipid. There is a dose-dependent effect observed for L3P on upregulation of CD25+ CD8 T cells from infected cows, while L5P effects were static. In contrast, L5P demonstrated a significantly stronger induction of CD25+ B cells from infected animals compared to L3P.

Interferon gamma response to Mycobacterium avium subsp. paratuberculosis specific lipopentapeptide antigen L5P in cattle

After Mycobacterium avium subsp. paratuberculosis (Map) infection the cell-mediated immune (CMI) response indicative of early Th1 activation may be detected using interferon-gamma release assay (IGRA). Currently, the purified protein derivatives (PPDs), i.e., the total extract of mycobacteria antigens are used to recall CMI responses against Map. This study aimed to assess the ability of the chemically synthesized Map specific cell wall lipopentapeptide L5P to induce CMI response in cows infected by Map compared to PPD. L5P and PPD elicited an IFN-γ response in 12 and 35 animals from two Map infected herds respectively, but IFN-γ was not detected in the 13 cows recruited from a non-infected herd. Levels of IFN-γ detected were higher with PPD than with L5P. There was no correlation between the IFN-γ response and the humoral response to Map or faecal culture.

High prevalence of hepatitis C virus infection and predominance of genotype 4 in rural Gabon

Hepatitis C (HCV) molecular epidemiology is documented poorly in central African countries. In response to this, a population-based study of 319 consenting adults resident in a remote village of Gabon was undertaken (mean age: 38 years; age range: 13-85+; sex ratio: 0.74). Screening for anti-HCV antibodies was performed using ELISA and recombinant immunoblot assay. Seropositive samples were assessed further with viral load and genotyping techniques. Sixty-six (20.7%) individuals were HCV seropositive. Viral loads ranged from 600 to 24.9 million IU/ml (median: 372,500). Seroprevalence and viral loads increased significantly with age (P < 10(-5) and P < 0.003, respectively). HCV sequences of the 5'UTR genome region were obtained from 60 (90.9%) samples and NS5B region sequences were obtained from 22 (36.6%) samples. All strains belonged to subtypes of genotype 4: 4e (72.7%), 4c (13.6%), 4p (4.5%), 4r (4.5%) and one unclassified genotype 4 strain. Evolutionary analysis of the subtype 4e sequences indicates a period of raised transmission during the early twentieth century.

Costs and cost-effectiveness of different follow-up schedules for detection of occupational hepatitis C virus infection

OBJECTIVE

The purpose of this study was to compare the costs and cost-effectiveness (C/E) of early hepatitis C virus (HCV) RNA testing (alternative-US recommendations) after occupational exposure to HCV with existing follow-up strategies: (1) French, anti-HCV antibodies and alanine transaminase (ALT) activity at months 1, 3 and 6; (2) European, monthly ALT activity for 4 months and anti-HCV antibodies at month 6; (3) and baseline-US, anti-HCV antibodies and ALT activity at month 6.

METHODS

A decision tree simulated each strategy for 7300 healthcare workers (HCWs) exposed to HCV each year in France, taking into account the impact of early diagnosis on the response to antiviral treatment and the deterioration of HCW quality of life after exposure.

RESULTS

For a HCV transmission risk of 0.5% after exposure, the French strategy led to the highest costs/person (181.40 euros) and the baseline-US strategy to the lowest (126.60 euros) (178.50 euros) for alternative-US). The shortest mean time to HCV infection diagnosis (1 month) and the lowest number of chronic hepatitis C (CHC) patients (1.9/7300 HCWs exposed) was obtained with the alternative-US strategy (vs 6 months and 7.9 CHC, respectively with baseline-US). Compared with the alternative-US, the French strategy was associated with higher costs and lower utilities, and the European with a higher incremental C/E ratio. Compared with the baseline-US strategy, the alternative-US strategy C/E ratio was 2020 euros per quality-adjusted life year saved.

CONCLUSION

In HCWs exposed to HCV, a strategy based on early HCV RNA testing shortens the period during which the HCW's wait for his HCV status, leads to lower risk of progression to CHC and is reasonably cost-effective.

Changing of hepatitis C virus genotype patterns in France at the beginning of the third millenium: The GEMHEP GenoCII Study

This cross-sectional study aimed to investigate, during a short period between 2000 and 2001, in a large population of patients with chronic hepatitis C, the epidemiological characteristics of hepatitis C virus (HCV) genotypes in France. Data from 26 referral centres, corresponding to 1769 patients with chronic hepatitis C were collected consecutively during a 6-month period. HCV genotyping in the 5'-non-coding region (NCR) was performed in each center using the line probe assay (LiPA, in 63% of cases), sequencing (25%) or primer-specific polymerase chain reaction (PCR) (12%). HCV genotypes 1a, 1b, 2, 3, 4, 5, non-subtyped 1 and mixed infection were found in 18, 27, 9, 21, 9, 3, 11 and 1% of our population, respectively. HCV genotype distribution was associated with gender, age, source and duration of infection, alanine aminotransferase (ALT) levels, cirrhosis, alcohol consumption, hepatitis B virus (HBV) and human immunodeficiency virus (HIV) coinfection. In multivariate analysis, only the source of infection was the independent factor significantly associated with genotype (P = 0.0001). In conclusion, this study shows a changing pattern of HCV genotypes in France, with i.v. drug abuse as the major risk factor, an increase of genotype 4, and to a lesser extent 1a and 5, and a decrease of genotypes 1b and 2. The modification of the HCV genotype pattern in France in the next 10 years may require new therapeutic strategies, and further survey studies.

Hepatitis C virus detection in follicular fluid and culture media from HCV+ women, and viral risk during IVF procedures

BACKGROUND

Hepatitis C virus (HCV) has been detected in sperm, but no data are available on follicular fluid (FF) collected on IVF procedures. The aim of this study was to: (i) search for HCV RNA in FF and in culture media at each step of IVF undergone by HCV(+) women; (ii) investigate the impact of blood contamination of FF induced by vascular injury associated with transvaginal ovarian puncture; (iii) assess risk for the embryo and the impact on the contamination rate of the newborn; and (iv) determine the viral risk presented by these fluids in order to define guidelines for the laboratory.

METHODS

FF from 22 IVF procedures performed in 17 HCV(+) women were classified as either clear, lightly bloody or bloody FF. Oocytes from each FF were washed and incubated in separated fertilization media. At 20 h after puncture (day 1), the fertilized oocytes were washed and transferred to fresh media until embryo transfer. HCV RNA was detected and quantified in FF and media using Cobas Amplicor and Cobas Monitor HCV RNA kits.

RESULTS

HCV RNA was positive in 39 of 44 FF samples, and viral loads increased with blood contamination. At day 1, after rinsing of oocyte-cumulus complexes, only 8 of 44 media were still positive. Viral loads were quantified in 5 of 8 positive media, were below the test sensitivity threshold in 4 of 5 HCV RNA-positive media, and just above it in the fifth medium. The day of transfer HCV RNA was undetectable in all media.

CONCLUSIONS

HCV RNA was detected in 89% of FF irrespective of the degree of blood contamination, and in 25% of the media at day 1. FF must be considered as potentially infected. Blood contamination increases HCV load in the FF. Rinsing oocytes seems significantly to discard the HCV RNA. It is too early to assess the impact of IVF on the contamination rate of HCV mothers' offspring. After counselling, attempting IVF in HCV(+) women is justified. Universal guidelines prevent nosocomial infection, and IVF does not specifically increase the professional risk.

Effects of hepatitis C virus on the apoptosis percentage of granulosa cells in vivo in women undergoing IVF: preliminary results

BACKGROUND

The aim of this study was to investigate the relationship between the apoptosis percentage of human luteinized granulosa cells (GC) and the presence of hepatitis C virus (HCV) in follicular fluid (FF).

METHODS

GC were isolated from FF of 12 women undergoing 12 IVF cycles: six were HCV+ with active viral replication and six HCV- serving as controls. No male partner was HCV+. HCV detection and quantification were assessed by reverse transcriptase-polymerase chain reaction in serum, FF and embryo-incubation medium. GC were analysed by flow cytometry after propidium iodide staining to measure the percentages of apoptotic GC. Routine IVF parameters were tabulated.

RESULTS

Mean +/- standard deviation (SD) serum and FF HCV viral loads were 3.58 +/- 4.25 x 10(6) and 0.14 +/- 0.10 x 10(6) IU/ml respectively. Mean percentages of apoptotic GC from HCV+ and HCV- women were 3.08 +/- 1.14 and 3.14 +/- 1.40% respectively. No statistically significant difference was found between these two groups concerning GC apoptosis and when we compared all IVF parameters. No HCV RNA was detected in embryo incubation media after 2 days of culture.

CONCLUSIONS

Comparing GC apoptosis percentages and usual IVF parameters in the HCV+ group versus the HCV- group, our preliminary study shows that active chronic HCV infection does not affect follicle development and IVF outcome in HCV+ women undergoing IVF. Furthermore, the risk of newborns becoming HCV-infected might not be increased by assisted reproductive technologies when performed in couples in which women are HCV+ and men HCV-.

[Evaluation of three testing strategies for detection of hepatitis C in a hospital medical consultation and in an HIV testing center]

AIMS

Testing for hepatitis C virus (HCV) is recommended. The purpose of this study was to evaluate the efficacy of HCV testing in a medical consultation without an appointment and in an HIV testing center based on three testing strategies: 1997 French Consensus Conference, "Lettre de la Direction Générale de la Santé" (January 1996), and extension to other risk factors.

PATIENTS AND METHODS

For 6 months a free blood test was offered to any patient with a risk factor according to the literature.

RESULTS

There were 1 736 new patients at the medical consultation and 1 616 at the testing center. The patients were younger at the testing center than at the medical consultation (31.1 vs 43.3 years; P<0.001). Acceptance of screening was better at the testing center (97.8% vs 75.2%; P<0.001). There were more patients exposed to one of the risk factors at the testing center (31.2% vs 13.9%; P<0.001). Tests were more efficient at the testing center: 30 HCV positive patients/1 616 (1.86%) vs 11/1 736 (0.63%, P<0.01). Tests based on the 1997 French Consensus Conference provided detection in 27/30 (90%) of HCV positive patients at the testing center but only 4/11 (36.3%) at the medical consultation (P<0.01).

CONCLUSION

Testing was effective in both places but was more efficient at the testing center. Efficacy of the testing strategies differs significantly according to the place of screening. At the testing center, screening can be restricted to patients with a history of intravenous drug use and blood transfusion. At the medical consultation, screening should be extended to other risk factors.

Autologous platelet concentrate as an adjunct in macular hole healing: a pilot study

PURPOSE

A pilot study was undertaken to assess the efficacy of autologous platelets in macular hole healing.

PATIENTS AND METHODS

Eight eyes of eight patients with stage 3 or 4 macular holes, two of which had failed to heal after previous vitrectomy and gas tamponade, were included. The procedure consisted of pars plana vitrectomy with removal of posterior cortical vitreous, stripping of associated epimacular membranes, 15% perfluoroethane-air tamponade, and instillation of autologous platelet concentrate onto the posterior pole. Strict postoperative facedown positioning was observed for 12 days. Postoperative evaluation included visual acuity measurement, biomicroscopic macular appearance and scanning laser ophthalmoscope examination. The follow-up period ranged from 3 to 13 months (mean, 7 months).

RESULTS

Of eight eyes, flattening of the surrounding retina and closure of the hole were achieved in seven (87.5%). Visual acuity improved two lines or more in four eyes (50%) Four eyes (50%) reached a postoperative visual acuity of 20/50 or more. Increased nuclear sclerosis was observed in six eyes (75%), and retinal detachment occurred in two eyes (25%).

CONCLUSIONS

Autologous platelet concentrate administered peroperatively in full-thickness macular holes seems to be a safe and effective adjunct to vitrectomy with removal of posterior hyaloid and gas tamponade. A larger multicenter randomized prospective study is underway to verify these encouraging results before advocating the use of autologous platelets in macular hole surgery.

Hepatitis C virus genotypes in French blood donors

The prevalence of different hepatitis C virus (HCV) genotypes in HCV infected individuals and the relation between the HCV genotypes and the source of the infection are controversial. The aim of this study was to determine the HCV genotypes in French blood donors. Fifty-one anti-HCV positive blood donors were studied with detectable serum HCV RNA by nested polymerase chain reaction (PCR) using primers derived from the 5' non-coding region. For genotyping HCV, we used a method based on analysis of the restriction fragment length polymorphisms (RFLP) after amplification by PCR of the HCV non-structural 5 (NS5) genome domain. Using this technique, the genotypes of 39 of the 51 blood donors (76%) were determined. Three previously described genotypes were found: 19 blood donors were infected by HCV genotype I (37%), 14 were infected by HCV genotype II (27%), 3 were infected by HCV genotype III (6%), and 3 were coinfected by two genotypes (6%). All three blood donors infected with two different genotypes were intravenous drug abusers. A past history of intravenous drug abuse was more frequent in blood donors with HCV genotype I. However, there was no difference in alanine transaminase (ALT) levels, histological lesions, and RIBA-2 patterns in blood donors infected with either HCV genotype I or HCV genotype II. These findings indicate that most HCV genotypes isolated from French blood donors belong to HCV genotype I and HCV genotype II, and that risk factors for HCV infection may differ for different genotypes of HCV.

Hepatitis C virus (HCV) viremia in human immunodeficiency virus-seronegative and -seropositive patients with indeterminate HCV recombinant immunoblot assay

Positivity of recombinant immunoblot assay (RIBA) for detection of antibodies to hepatitis C virus (anti-HCV) is usually associated with HCV viremia. The significance of an indeterminate RIBA result, defined by reactivity to only one HCV antigen, is unclear. Whether anti-human immunodeficiency virus (HIV)-negative or -positive subjects with an indeterminate RIBA have HCV viremia detectable by polymerase chain reaction was investigated. An indeterminate RIBA was found in 48 (15%) of 318 anti-HIV-negative and 38 (23%) of 167 anti-HIV-positive subjects (P < .05). Clinical stage was IV-C-1 or IV-C-2 in 82% of those anti-HIV-positive. HCV viremia was found more frequently in anti-HIV-positive (89%) than in anti-HIV-negative subjects (50%) with an indeterminate RIBA (P < .05). These results suggest an impaired anti-HCV response associated with HIV infection.

Detection and quantitation of serum HCV-RNA by branched DNA amplification in anti-HCV positive blood donors

The detection of serum HCV-RNA needs to be standardized. The aim of this study was to assess the effectiveness of the branched DNA amplification method in detecting and quantitating serum HCV-RNA in 54 blood donors, 33 with and 21 without increased serum alanine aminotransferase levels and with detectable serum HCV-RNA by polymerase chain reaction. HCV-RNA was detected by branched DNA signal amplification in 42/54 (77%) of the blood donors. Positivity rates were not different among the 21 blood donors with normal and the 33 blood donors with increased serum alanine aminotransferase levels (86% and 76%, respectively). Median serum HCV-RNA levels were not different among donors with or without increased serum alanine aminotransferase levels (28.6 x 10(5) Eq/ml and 14.7 x 10(5) Eq/ml, respectively). There was no significant correlation between serum alanine aminotransferase levels and serum HCV-RNA levels. These findings show that branched DNA signal amplification identifies most of the donors with true hepatitis C virus viremia and that the level of hepatitis C virus replication is not correlated to serum alanine aminotransferase levels.

Chronic non-B, non-C hepatitis among blood donors assessed with HCV third generation tests and polymerase chain reaction

Forty five blood donors with increased serum aminotransferases levels had liver histologic assessment and were tested for antibodies to hepatitis C virus (anti-HCV) with second and third generation ELISAs and RIBAs, and for HCV RNA with polymerase chain reaction (PCR) in serum and liver tissue. Twenty-nine of these 45 donors (65%) had steatosis without chronic hepatitis. Sixteen (35%) had chronic hepatitis. Twelve had evidence of HCV infection. Four had no evidence of HCV infection demonstrable by ELISA, RIBA or PCR. These four patients had no known cause of chronic hepatitis and no risk factor for parenterally acquired viral infection was found in them. This observation supports the hypothesis that a non-B, non-C virus might be implicated in chronic hepatitis. However, this hypothesis remains to be demonstrated.

[Collection of anti-HBs hyperimmune plasma: stimulation by Genhevac B in weakly immunized donors]

The need for anti HBs globulin is still important in spite of the development of the HBs vaccination. Twenty-two plasma donors, immunized against Hepatitis B virus (HBV) with titers of anti HBs between 100 and 6,000 milli International Units per ml (mUI/ml), received two injections of Genhevac B Pasteur at a one-month interval, and a third injection two months later whenever the answer was still under 6,000 mUI/ml, which is the minimum necessary in order to obtain a specific globulin compatible with the National Standard (100 UI/ml) from plasma fractions. In this programme, no severe adverse reaction was documented, and the mean rate of anti HBs rose from 1,322 to 35,173 mUI/ml, with a mean multiplying factor of 20.2. This result was reached after the first injection in "responders"; the third injection did not increase the titer in "non responders". The titer was still above 6,000 mUI/ml after six months in all the donors with more than 1,500 mUI/ml before vaccination. This limit is suggested to select plasma donors for vaccination, and a booster injection could be proposed every six months.

[Adult celiac disease and type 1 diabetes: a severe and sometimes unknown genetic association]

In 6 type 1 (insulin-dependent) diabetics, treated with insulin since the age of 2 to 35 years (mean 12), coeliac disease was diagnosed between the 10 th and 73 th years of age (mean 26). Five were of North African origin. Digestive symptoms and severe malnutrition were present in all of them, associated, in the two younger, with a major growth retardation and, in one, multiple pathologic fractures. Biopsy of the small intestine demonstrated, in all, total or subtotal villous atrophy. The metabolic control of diabetes was poor, with frequent hypoglycaemic attacks, induced by minute insulin doses. Severe chronic complications of diabetes were detectable in all of them. Plasma anti-reticulin antibodies were present, at high titer before starting the gluten-free diet, declining slowly after starting this diet, and negative in the patients who followed this diet. Among the genetic markers (which were determined in 4), HLA A1 was present in 4, B8 and DR3 in 3 and DR4 in 3. The DR7 was not detected. The gluten-free diet, memorized by the patients by the use of simple rules, improved the digestive symptoms, and insulin doses could then be increased. The overall prognosis remained poor, due to diabetic complications and sociologic desinsertion. Coeliac disease occurs in 1 to 2% of type 1 diabetics and 4-6% of the coeliac patients are diabetics. Diabetic subjects from North Africa are at high risk of this association. Misdiagnosis of the coeliac disease compromises the metabolic control and nutritional state.(ABSTRACT TRUNCATED AT 250 WORDS)

[Cost of transfusion in AIDS. Experience at the Claude-Bernard Hospital apropos of 28 cases]

The study of 28 confirmed cases of AIDS shows that transfused patients use a large amount of hospital's blood products, especially platelets. For these patients, the average cost of transfusion is higher than that, for intensive care unit patient's. The use of irradiated products increases the cost (+ 35%). As there is a shortage of donors, if the present precautions are respected, there is no reason why the hospital should not continue to ask the patient's family and circle of friends, to donate blood.