Identification of Rhodococcus, Gordona and Dietzia species using carbon source utilization tests (“Biotype-100” strips)

The “Biotype-100” identification system (BioMérieux, La Balme-les-Grottes, France) based on carbon source utilization was evaluated for its ability to discriminate among 10 species of Rhodococcus, 7 species of Gordona and one species of Dietzia. The type strains of three species of Tsukamurella and 8 species of Nocardia were also included in the study. Results were compared with chemotaxonomic and conventional data. Carbon source utilization was shown to be reliable, rapid and easy to use when compared with standard identification methods. The 29 species tested were unambiguously separated by carbon source utilization tests. Rhodococcus equi was found to be heterogenous.Les galeries “Biotype-100” (BioMérieux) ont été utilisées pour différencier 10 espèces du genre Rhodococcus, 7 espèces du genre Gordona et 1 espèce du genre Dietzia entre elles. Les souchestypes de 3 espèces du genre Tsukamurella et 8 espèces du genre Nocardia ont été incluses dans cette étude. Les résultats ont été comparés avec ceux des études chimiotaxonomiques et ceux obtenus avec les galeries d'identification classiques. Les galeries Biotype-100 sont sûres, rapides et faciles à utiliser par rapport aux galeries classiques. Les 29 espèces étudiées ont été identifiées sans aucune difficulté. L'espèce Rhodococcus equi s'est révélée hétérogène.     

Wild ruminants in the area of the North-Western Poland as potential reservoir hosts of <Emphasis Type="Italic">Bartonella schoenbuchensis</Emphasis> and <Emphasis Type="Italic">B. bovis</Emphasis>

The aim of this work was to examine if the game species from the north-western Poland, roe deer (Capreolus capreolus), red deer (Cervus elaphus) and wild boar (Sus scrofa), may be reservoir hosts of bacteria from the genus Bartonella, and whether the sheep tick (Ixodes ricinus) is their vector. To this end, the prevalence of Bartonella DNA in the tissues of these game species was measured, just as in sheep ticks (I. ricinus) infesting them, and ticks collected from plants in the hunting area. The prevalence of Bartonella DNA was 39% (23/59) in roe deer and 35% (7/20) in red deer. No Bartonella DNA was detected in any of the 21 wild boars. The presence of Bartonella DNAwas detected in 1.9% of ticks infesting roe deer (2/103), while no pathogen DNA was found in the 20 ticks infesting the red deer and the 3 ticks infesting wild boars, or the 200 ticks collected from plants. Amplicons of two different lengths were obtained; 198 bp, characteristic for B. bovis, and 317 bp, characteristic for B. schoenbuchensis, which were confirmed later by sequencing. The examined ruminants are probably the reservoir hosts of B. schoenbuchensis and B. bovis in the biotope of the Puszcza Wkrzańska Forest, and wild boars do not participate in the Bartonella propagation in the environment. I. ricinus is unlikely to be the main vector of Bartonella species detected in the examined roe deer and red deer; probably other bloodsucking arthropods, parasitizing wild ruminants, play this role.     

Supplément 1996 (no. 40) to the Kauffmann-White scheme

This supplement reports the characterization of 13 new Salmonella serovars recognized in 1996 by the WHO Collaborating Centre for Reference and Research on Salmonella: 8 were assigned to S. enterica subsp. enterica, 3 to subspecies salamae and 2 to subspecies diarizonae.     

Identification d’Enterocytozoon bieneusi par PCR dans les selles des patients immunodéprimés tunisiens

Introduction

Intestinal microsporidiosis is recognised as an important cause of opportunistic parasitosis in immunocompromised patients, especially HIV-infected patients. Enterocytozoon bieneusi is the common causal agent. The diagnosis of intestinal microsporidiosis has usually based on microscopic detection of the spores of microsporidia species in stool samples, requires additional staining techniques as Modified Weber's trichrome stain. However, the detection of the spores can be difficult and species determination, which is important for defining the appropriate treatment, is impossible. Polymerase chain reaction (PCR)-based methods have been successfully used for detection of microsporidian infections. They are more sensitive and are able to identify microsporidia species. The purpose of this study is to identify E. bieneusi to adapt treatment and assess the true prevalence of the intestinal microsporidiosis due to this species in compromised patients in Tunisia.

Patients and methods

One hundred and eighteen stools from immunocompromised patients, with a symptomatology in favour of the intestinal microsporidiosis, were analysed using light microscopy after staining with Modified Weber's trichrome stain and PCR.

Results

Only four were positive by Modified Weber's trichrome stain whereas eleven stools were positive by PCR, giving a prevalence of 20% in HIV-infected patients and 5,35% in human immunodeficiency virus-negative patients.

Conclusion

This study confirms the usefulness of PCR in the diagnosis of the intestinal microsporidiosis due to E. bieneusi. Indeed, PCR has greater sensitivity than Modified Weber's trichrome stain and can identify the species of microsporidia in order to adapt the treatment.     

Les leishmanioses humaines au Maroc : une diversité nosogéographique

Leishmaniases in Morocco are endemic diseases. Three forms of leishmaniasis are reported, visceral leishmaniasis, cutaneous leishmaniasis caused by Leishmania tropica and cutaneous lesions due to Leishmania major. Leishmania infantum, a common parasite inducing visceral leishmaniasis, was observed thereafter in cutaneous lesions. The first case of cutaneous leishmaniasis due to L. tropica was isolated since 1987. But, this parasite was shown to be more polymorphic with almost 8 zymodemes. However, these zymodemes are not all transmitted by Phlebotomus sergenti and not all isolated from human reservoir. Regarding the clinical aspect, cutaneous leishmaniasis with L. tropica is described as a single lesion starting as a nodule at the site of inoculation. A crust develops centrally which may fall away exposing an ulcer which heals gradually. The second cutaneous form is that caused by Leishmania major. It was known in villages located in the southern slopes of the Atlas Mountains. Clinically, the lesion is often severely inflamed and ulcerated and heals in 4–6 months. The epidemiologic cycle of this rural form, include Phlebotomus papatasi as the proven vector and a commensally rodent, Meriones shawi grandis as the reservoir. However, visceral leishmaniasis in Morocco has been known since 1921. It is especially located in the North. The responsible parasite is L. infantum MON 1. Two species of the sand fly are involved in the transmission of this form, P. ariasi and P. perniciosus. In infected man, the clinical signs are non-tender splenomegaly, with or without hepatomegaly, wasting and pallor of mucous membranes. Even though L. infantum MON1 is responsible of the disease, some canine cases were reported to be caused by Leishmania tropica.     

Les dermatomycoses à Trichophyton verrucosum à Sfax–Tunisie

Trichophyton verrucosum is a zoophilic dermatophyte. It can be responsible of various clinical aspects especially inflammatory lesions of skin and scalp. The aim of this study was to determine the clinical and epidemiological characteristics of dermatophytosis due to T. verrucosum.

Patients and methods

It is a retrospective study realized on 35,918 patients suspected to have superficial mycoses in a 13-year-period (from 1998 to 2010).

Results

T. verrucosum was isolated in 178 patients corresponding to 1.2% of all dermatophytosis. Ochraceum variety was the most frequent (60%), followed by album variety (40%). Frequency of isolated T. verrucosum increased passing from one case in 1998 to 37 cases in 2010. The mean age was 22.7 years (range: 1.5–71 years). A percentage of 74.2 of our patients were male and 61% were from urban regions. A percentage of 32.5 could link their clinical lesions to contact with an animal (mainly cattle and sheep). Other family members were infected by tinea in 7.3% of cases. Tinea corporis was the most frequent (62.2%), followed by tinea capitis (31.6%). Ten cases of sycosis, one case of tinea pedis and one case of pubic tinea were diagnosed. Lesions of skin were erythemato-squamous (82.5%) and pustulo-inflammatory (17.5%), affecting mainly upper limb (58.3%) and face (25.8%). For tinea capitis, lesions were squamous (30.8%) and pustulo-inflammatory (41%). Eleven cases of kerion celsi were diagnosed (28.2%). Patients were affected in one site (79.7%), two sites (16.9%) and three or more (3.4%).

Conclusion

Dermatophytosis due to T. verrucosum is in recrudescence in our region. This finding may be explained by changing behaviors and activities of the population with a low socioeconomic level who kept a larger number of domestic animals at homes.     

AFLP allows the identification of genomic markers of ruminant Chlamydia psittaci strains useful for typing and epidemiological studies

Amplified fragment length polymorphism (AFLP), a novel method for molecular typing, was evaluated for its ability to differentiate among a group of highly related Chiamydia psittaci strains isolated from ruminants and belonging to serotype 1. A total set of 12 strains were included in this study, 10 strains inducing abortion in ruminants and 2 strains from faecal samples. For the AFLP analysis, the total purified genomic DNA of each strain was submitted to a one-step digestion-ligation reaction for 3 h at 37°C. DNA was digested with a single restriction endonuclease Mspl and ligated to specially constructed adapters. Subsequently, restricted fragments were selectively amplified under high stringency PCR conditions using primers complementary to the adapters. Amplified products were then resolved on agarose gel electrophoresis. The method is easy to perform, fast and reproducible. AFLP enabled characterization of C. psittaci strains at the infra-subspecific level. Thus, AFLP led to the identification of a cluster of strains on the basis of their AFLP patterns, constituted by French chlamydial isolates. It also permitted differentiation among strains in relation to host origin and to clinical syndromes. These data confirmed the highly discriminative power of AFLP towards the differentiation of closely related ruminant C. psittaci strains. The analysis will need to be applied to more samples to check the usefulness of AFLP markers in epidemiological and evolutionary studies.     

Distribution of catabolic pathways in some hydrocarbon-degrading bacteria from a subsurface polluted soil

Enrichment cultures on naphtha solvent were used to select aromatic hydrocarbon-degrading bacteria from a BTEX (benzene, toluene, ethylbenzene, xylene)-contaminated subsoil obtained from beneath a paint factory located in Milan, Italy. Fifteen isolated strains were studied for their different biodegradative capacities. Among these, 13 were able to grow on naphtha solvent. Ten were identified as Pseudomonas putida and three as Pseudomonas aureofaciens. Two other degraders were identified as Pseudomonas aeruginosa and Alcaligenes xylosoxidans subsp. denitrificans. Further molecular characterization of the isolates was carried out by randomly amplified polymorphic DNA analysis to ascertain that all the studied strains belonged to different haplotypes. The isolates were characterized for the presence of genes encoding for toluene dioxygenase, xylene monooxygenase and catechol 2,3-dioxygenase by polymerase chain reaction analysis and by Southern analysis. P. putida strain CM23, which showed homology with xylA,M, xylE and todC1C2BA genes, possessed multiple pathways which enabled the strain to grow on benzene, toluene and m-xylene.     

Loss of λ prophage recombinogenicity in UV-irradiated Escherichia coli: the role of host genes ruvA, ruvB, ruvC, and recG

Earlier studies have revealed a radiation-induced process leading to the loss of λ prophage recombinogenicity. The process takes place in UV-irradiated Escherichia coli cells, and renders the prophage incapable of site-specific recombination with the host chromosome, and of general recombination with an infecting homologous phage. It was found that the inhibition of prophage recombinogenicity depends on functional RecBCD enzyme of E. coli. In this work, the role of ruvABC and recG genes in the inhibitory process was assessed. The products of these genes are known to act at the last step of homologous recombination and recombinational DNA repair by catalyzing the resolution of recombination intermediates (the Holliday junctions). Irradiated prophage retained its ability to recombine in ruvA, ruvB, ruvC, and recG mutants. These results suggest that in addition to RecBCD enzyme, RuvABC and RecG proteins are also involved in the inhibition of prophage recombinogenicity. We infer that RuvABC and RecG act in this process before RecBCD, probably by processing the Holliday junctions formed upon replication arrest, and thereby providing double-stranded DNA breaks as substrate for RecBCD-mediated recombinational repair of UV-damaged bacterial chromosome.     

Regulation and role of transforming growth factor-β in immune tolerance induction and inflammation

Transforming growth factor-beta (TGF-beta) is known to mediate pleiotropic functions both inside and outside the immune system. Recent progress in this field underlines the role of TGF-beta in regulatory T (Treg) cells, where it participates in both suppression and differentiation. In addition, recent information highlights the role of TGF-beta in repair responses that lead to matrix deposition and tissue remodelling. Many chronic inflammatory diseases, such as asthma, profit from the suppression of specific immune responses by TGF-beta; however, TGF-beta-mediated tissue remodelling can be a serious complication in such diseases.     

Supplement 1999 (no. 43) to the Kauffmann-White scheme

This supplement reports the characterization of 26 new Salmonella serovars recognized in 1999 by the WHO Collaborating Centre for Reference and Research on Salmonella: 15 were assigned to S. enterica subsp. enterica, seven to subspecies salamae, two to subspecies diarizonae, and one to subsp. houtenae; and one to S. bongori. In addition, the antigenic factor H:z89 is described.     

Evidence for association of lipopolysaccharide with Pseudomonas fluorescens strain MF0 porin OprF

Lipopolysaccharide (LPS) was found to be associated with the major outer membrane protein OprF of the psychrotrophic bacterium Pseudomonas fluorescens MF0, using two OprF purification procedures. OprF, purified under mild conditions, presented two types of association with LPS: tight (tLPS) and slight (sLPS), both of type R. LPS protected OprF from heat modification and trypsin degradation and facilitated the reincorporation of purified OprF into an artificial lipid bilayer without affecting its pore-forming activity. The size of the OprF channel depended on cell growth temperature, as did the extent of LPS phosphorylation: we suggest that LPS may be involved in modifications of OprF pore formation.     

Detection and quantification of<Emphasis Type="Italic"> Mycobacterium leprae</Emphasis> in tissue samples by real-time PCR

Real-time PCR technology has improved molecular diagnostics of many pathogens, but no such test is available for Mycobacterium leprae. In this report we describe the establishment and the pre-clinical evaluation of such an assay. The test achieved a theoretical analytical sensitivity limit of 194 M. leprae cells per skin biopsy specimen and facilitated quantification of mycobacteria in tissue over a range of 54–54,000,000 cells per sample. In punch skin biopsies from 39 untreated Ugandan patients with newly diagnosed leprosy, the clinical diagnosis could be confirmed in 88.9% of multibacillary and 33.3% of paucibacillary (microscopically negative) patients. Real-time detection thus did not increase the clinical sensitivity of PCR as compared to conventional protocols, in spite of its evidently high analytical sensitivity. On the other hand, as still no culture system exists for M. leprae, the assay appears to be a robust tool for detection of the bacterium in selected clinical situations, as well as for quantitation in experimental settings.     

Deep sequencing of Cotesia vestalis bracovirus reveals the complexity of a polydnavirus genome

Here we completed the whole genome sequence of Cotesia vestalis bracovirus (CvBV) by deep sequencing and compared the genome features of CvBV to those of other polydnaviruses (PDVs). The genome is 540,215 base pairs divided into 35 genomic segments that range from 2.6 to 39.2 kb. Comparison of CvBV with other PDVs shows that more segments are found, including new segments that have no corresponding segments in other phylogenetically related PDVs, which suggests that there might be still more segments not being sequenced in the present known PDVs. We identified eight gene families and five genes in CvBV, including new genes which were first found in PDVs. Strikingly, we identified a putative helicase protein displaying similarity to human Pif1 helicase, which has never been reported for other PDVs. This finding will bring new insights in research of these special viruses.     

Kératomycose grave à Fusarium solani induite par un corps étranger tellurique : à propos d’un cas au Sahara marocain

We report a case of severe keratitis due to Fusarium solani in a young man in the Sahara in Morocco where the climate is arid. This patient reported had a grain of sand in his right eye for a week after a sandstorm. On admission he had a corneal abscess. Despite rapid diagnosis and initiation of treatment with available antifungal drugs: amphotericin B and natamycin eye drops, the prognosis worsened and led to the enucleation of the right eye. Faced with a suspected eye infection after a microtrauma caused by grains of sand carried by a sandstorm, it is important to take biological samples to search for fungal infections among other. It is also important to have new triazole antifungal drugs available to treat ocular mycosis rapidly and effectively.