Emergence of methicillin-resistant Staphylococcus aureus (MRSA) ST8 in raw milk and traditional dairy products in the Tizi Ouzou area of Algeria.

Staphylococcus aureus is one of the leading causes of food-borne illness worldwide. Raw milk and dairy products are often contaminated with enterotoxigenic strains of this bacterium. Some of these strains carry antimicrobial resistance, leading to a potential risk for consumers. The aim of this study was to characterize S. aureus strains circulating in raw milk and traditional dairy products for carriage of staphylococcal enterotoxin (se) genes and antimicrobial resistance. Overall, 62 out of 270 samples (23%) were contaminated with S. aureus, and 69 S. aureus strains were identified. We studied the enterotoxin genes using 2 multiplex PCR targeting 11 se genes. Seventeen (24.6%) isolates carried one or more genes encoding for staphylococcal enterotoxins. The most commonly detected se genes were seb and sep, followed by seh, sea, and see. Using the disk diffusion method, we found that resistance to penicillin G and tetracycline was the most common. Eleven isolates of methicillin-resistant S. aureus (MRSA) carried the mecA gene. All MRSA isolates belonged to the same spa type (t024) and sequence type (ST8), and carried the seb and sep enterotoxin genes. However, none of them carried the Panton Valentine leukocidin gene (lukF/S-PV). The presence of enterotoxigenic S. aureus strains, including MRSA, in raw milk and dairy products, raises a serious public health concern, because these strains may cause food poisoning outbreaks, be disseminated to the population, or both.

[NADIS 2000, development of an electronic medical record for patients infected by HIV, HBV and HCV]. / NADIS 2000, développement d'un dossier médical informatisé pour les patients infectés par VIH, VHB et VHC.

OBJECTIVE: to develop an electronic medical record for patients living with HIV, HBV or HCV in order to improve their management, facilitate communication between all the caregivers, and to create a useful medical database for research and assessments. This project (NADIS 2000) involved 6 centres of Infectious Diseases in France in partnership with Fédialis Médica (subsidiary of the GSK group in France). METHODS: A specifications sheets was drawn-up by a piloting Committee regrouping the various correspondents in each centre and a computer expert representing Fédialis Médica. A Scientific and Development committee regrouped the heads of departments of each centre and the representatives from Fédialis Médica and GSK and was charged with defining the general concept of the project and guaranteeing the scientific and clinical aspects. RESULTS: NADIS 2000 version 1.0 was activated in the departments of infectious diseases in Nice and Toulouse in November 2000 and in others Units at the end of 2001. NADIS 2000 permitted real-time use by the physicians in the Outpatients and Day-care Units and was easily handled by all the practitioners. Its use was eased by the principles clearly defined before its application (department project, progressive but exhaustive use), an intuitive interface simulating a consultation, and functions proposing direct benefits for the physicians (graphical visualization of the biological variables, printing of prescriptions and letters). CONCLUSION: The activation and input methods of NADIS 2000 are user friendly and the physicians find it rapidly easy to use. New functional aspects are being developed as well as its use in other hospital departments.

Radiotherapeutic effect on oropharyngeal flora in head and neck cancer.

The effect of radiotherapy on oropharyngeal bacterial and mycotic flora was studied. Thirty five patients were included from whom swabs were taken before and at the end of irradiation. Fifteen controls were included.It was found that Streptococcus pneumoniae was significantly decreased at end of irradiation, while there wan an increase in Staphylococcus aureus. Pseudomonas, Bacteroides and Candida species. There was no change in culture and sensitivity pattern prior to and after radiotherapy.

Molecular epidemiology of nga and NAD glycohydrolase/ADP-ribosyltransferase activity among Streptococcus pyogenes causing streptococcal toxic shock syndrome.

Severe invasive group A streptococcal (GAS) infections emerged in the late 1980s, yet no single virulence factor has been common to all isolates from infected patients. A strong association was recently found between isolates of such cases (regardless of M type) and the production of NAD glycohydrolase (NADase). Of interest, all M-1 strains isolated after 1988 were positive for NADase, whereas virtually all M-1 GAS were previously negative for NADase. Genetic analysis demonstrated that GAS isolates were >96% identical in nga and >99% identical in their upstream regulatory sequences. Furthermore, because NADase-negative strains did not produce immunoreactive NADase, we concluded that additional regulatory element(s) control NADase production. NADase purified from GAS altered neutrophil-directed migration and chemiluminescence responses and had potent ADP-ribosyltransferase activity. In summary, the temporal relationship of NADase expression, alone or with other streptococcal virulence factors, may contribute to the pathogenesis of invasive GAS infections.

Variable susceptibility to opsonophagocytosis of group A streptococcus M-1 strains by human immune sera.

Immunity to group A streptococci (GAS) is thought to be related to the acquisition of type-specific antibody directed against the M protein. However, recent work suggests that immunity may only be strain and not M-type specific. Therefore, susceptibility of 70 different GAS M-1 strains to opsonization and killing by convalescent sera was compared by using a highly sensitive chemiluminescence assay and by standard bactericidal assay. Sequencing of the emm1 gene in 10 strains with variable susceptibility to opsonization revealed 100% homology in 9 strains. Several substitutions in the N-terminal and 2 in the A3 repeat regions of strain CS-190 were associated with profound resistance to opsonization. Thus amino acid substitutions within different regions of the M-1 protein molecule may adversely affect opsonization by immune sera. In addition, non-M protein factors from identical M types influence susceptibility to phagocytosis. These findings may in part explain the persistently high prevalence of M-1 strains worldwide over the last 15 years.

Pregnancy-associated breast cancer.

Pregnancy-associated breast cancer, which is defined as all breast cancer diagnosed during pregnancy or within the following year, is a relatively rare finding. Due to the particular difficulties in the diagnosis of breast cancer during this period, pregnant women tend to present more advanced disease at diagnosis. Four cases of pregnancy-associated breast cancer referred to our Institute are described as a contribution to the knowledge of this disease.

Genetic determinants of immunity and integration of temperate Myxococcus xanthus phage Mx8.

An 8.1-kb fragment of the temperate Myxococcus xanthus phage Mx8 genome, when cloned into a plasmid vector, permits site-specific integration of the plasmid and confers superinfection immunity. Sequence analysis of a 9.5-kb region of Mx8 DNA containing this fragment reveals 19 densely packed open reading frames, four of which have predicted products with known or suspected activities. The Mx8 imm gene, required for superinfection immunity, has a sequence similar to that of Arabidopsis thaliana G-box-binding factor 1. Mx8 makes a DNA adenine methylase, Mox, and integrase, Int, related to other methylases and integrases. The int gene has two alternate translation initiation codons within the extensively overlapping uoi (upstream of int) gene. Comparison of the predicted product of the uoi gene with Salmonella phage P22 and Streptomyces plasmid Xis proteins shows that temperate phage excisionases may use variations of a helix-turn-helix motif to recognize specific DNA sequences.

Temperate Myxococcus xanthus phage Mx8 encodes a DNA adenine methylase, Mox.

Temperate bacteriophage Mx8 of Myxococcus xanthus encapsidates terminally repetitious DNA, packaged as circular permutations of its 49-kbp genome. During both lytic and lysogenic development, Mx8 expresses a nonessential DNA methylase, Mox, which modifies adenine residues in occurrences of XhoI and PstI recognition sites, CTCGAG and CTGCAG, respectively, on both phage DNA and the host chromosome. The mox gene is necessary for methylase activity in vivo, because an amber mutation in the mox gene abolishes activity. The mox gene is the only phage gene required for methylase activity in vivo, because ectopic expression of mox as part of the M. xanthus mglBA operon results in partial methylation of the host chromosome. The predicted amino acid sequence of Mox is related most closely to that of the methylase involved in the cell cycle control of Caulobacter crescentus. We speculate that Mox acts to protect Mx8 phage DNA against restriction upon infection of a subset of natural M. xanthus hosts. One natural isolate of M. xanthus, the lysogenic source of related phage Mx81, produces a restriction endonuclease with the cleavage specificity of endonuclease BstBI.