Validation of diffusion methods for macrolide susceptibility testing of Helicobacter pylori.

Helicobacter pylori resistance to macrolides is increasing, and the need for susceptibility testing has become crucial. The only standardized method is agar dilution, which is not adapted to clinical practice. The present work aimed: (1) to optimize the technical conditions and to assess the reproducibility of the E-test and disk diffusion method for macrolides susceptibility testing of H. pylori, and (2) to assess the performances of these two phenotypic methods in detecting strains harboring a resistance mechanism to macrolides. We used 191 isolates collected in nine centers of France and Belgium. Phenotypic tests were performed on Mueller-Hinton agar supplemented with 10% horse blood, inoculated with a 2-day-old H. pylori suspension (10(8) CFU/ml), and incubated for 72 hr at 37 degrees C under microaerophilic conditions. The reproducibility studied on two randomly selected strains was better for disk diffusion than for the E-test for both clarithromycin and erythromycin. For a subset of 10 strains, the MICs of erythromycin and clarithromycin did not differ from more than one two-fold dilution when determined by E-test or agar dilution method. The breakpoints were for MICs: 1 mg/L for both clarithromycin and erythromycin and for inhibition diameters, 22 mm for clarithromycin and 17 mm for erythromycin. There was a 100% concordance between susceptibility to erythromycin and clarithromycin. However, the susceptible and resistant populations were better separated by testing erythromycin. Of 34 resistant strains, two lacked the A2142G and A2143G point mutations in 23S rRNA by PCR-RFLP. None of 15 tested sensitive strains were positive for one of these two point mutations. For clinical practice, we recommend to assess macrolide susceptibility of H. pylori by using one of these two phenotypic methods under the described technical conditions.

Selectivity of proteinuria as determined by high pressure liquid chromatography.

The methods used for measurement of the selectivity of glomerular filtration are usually long and tedious. We report the use of protein HPLC for the determination of the selectivity index. When compared to the conventional procedure, this new approach gave 82% correlation. This method offers many advantages in clinical chemistry due to its rapidity, sensitivity and the objectivity of data analysis.

Vancomycin prophylaxis and intraocular contamination during cataract surgery.

PURPOSE: To investigate the effect of vancomycin added to the intraocular irrigation solution to prevent anterior chamber contamination during phacoemulsification. SETTING: Centre Hospitalier, Villeneuve-Saint-Georges, France. METHODS: A group of 372 patients having cataract extraction by phacoemulsification was divided into two consecutive, nonrandomized groups. The first group (n = 190) was a control; there was no antibiotic in the irrigation solution. The second group (n = 182) received vancomycin in the irrigation solution. Intraocular fluid was aspirated at the end of surgery and injected into a blood culture bottle to evaluate bacterial contamination of the anterior chamber. RESULTS: There was no between-group difference in bacterial intraocular contamination. Eight samples in the first group were contaminated and nine in the second group. All contaminants were gram-positive vancomycin-sensitive organisms. CONCLUSIONS: Adding vancomycin to the intraocular irrigation solution during cataract surgery had no effect on the occurrence of intraocular contamination as evaluated by anterior chamber taps.

Serodiagnosis of postnatally and prenatally induced toxoplasmosis in sheep.

Nineteen pregnant (45 to 90 days of gestation) and 9 nonpregnant ewes were inoculated orally with 1,000 or 10,000 oocysts of Toxoplasma gondii. Pregnant ewes were euthanatized at days 14 (2 ewes), 21 (1 ewe), 23 (1 ewe), 28 (2 ewes), 35 to 42 (6 ewes), and 49 to 62 (6 ewes), and antibody titers in fetal and maternal sera were assayed, using the modified agglutination, latex agglutination, indirect hemagglutination, and dye tests. Although all ewes developed antibody titers of greater than or equal to 1,024 within 28 days after inoculation, fetuses were seronegative up to 28 days, using the modified agglutination test. Toxoplasma gondii antibodies were found in fetuses, using the modified agglutination and dye tests 35 days after ewes were inoculated. Latex agglutination and indirect hemagglutination tests were insensitive for detection of T gondii antibodies in ovine fetal sera. Toxoplasma gondii antibody titers in nonpregnant ewes were similar to those in pregnant ewes. Passively acquired T gondii antibodies from the colostrum decreased from 1,024 to less than 16 between 49 and 56 days of age in 1 lamb and between 62 and 106 days in its twin.

[Endoscopic diagnosis of a biliodigestive fistula of tuberculous origin revealing acquired immunodeficiency syndrome]. / Diagnostic endoscopique d'une fistule bilio-digestive d'origine tuberculeuse révélatrice d'un syndrome d'immunodéficience acquise.

We report the case of a 32-year-old Malian man with abdominal tuberculosis revealing acquired immunodeficiency syndrome. A gastroscopy was made for epigastric pain and showed caseum in a digestive fistula with acid fast bacilli. Mycobacterium tuberculosis infection was confirmed by sputum culture. An early antituberculous therapy was prescribed. Outcome was good with rapid fistula closing and slower mass diminution of the abdominal lymph nodes. This case report confirms nodal tuberculosis as a possible cause of digestive fistulae. Rapid endoscopic diagnosis of this tuberculous fistula led to diagnosis of acquired immunodeficiency syndrome and early adapted medical treatment without invasive diagnostic methods.

[Interleukin-6 and other cytokines in the aqueous humor in uveitis and endophthalmitis]. / Interleukine-6 et autres cytokines dans l'humeur aqueuse au cours d'uvéites et d'endophtalmies.

We studied aqueous humour and serum level of 4 cytokines during uveitis and endophthalmitis: Interleukin 6, Gamma interferon, tumor necrosis factor and Granulocyte-macrophage colony stimulating factor. High levels of IL-6 were found in aqueous humour during ocular inflammation and infection. This elevation of IL-6 level was more constant and more important in the endophthalmitis group (mean level 2.992 pg/ml) than in the uveitis group (mean level 1.480 pg/ml). During endophthalmitis no evident relation was found between IL-6 level and clinical course or aspect, or bacteriological results of anterior chamber tapes. In the uveitis group, no relation was found between IL-6 level and clinical aspect or aetiology.

[Bacteriological study of the intraocular fluid at the end of cataract surgery]. / Etude bactériologique du liquide intra-oculaire en fin d'intervention de cataracte.

The authors studied bacterial contamination of the anterior chamber during extracapsular cataract extraction with intraocular lens implantation. A first study was conducted to determine the rate of contamination of anterior chamber aspirates, before surgery, in 46 patients undergoing cataract extraction. A second study concerned 200 patients undergoing extracapsular extraction with posterior chamber lens. Anterior chamber fluid was aspirated at the end of surgery, and inoculated into blood culture bottles. Bacteriological results were positive in 11 cases, and were compared with conjunctival smears. The way in which aqueous humor was aspirated and inoculated is described. The bacteriological method was tested with a small inoculum of bacteria. Bacteriological study of intraocular fluid at the end of cataract surgery might be useful in the diagnosis and treatment of postoperative endophthalmitis.

[Bacterial contamination: epidemiology in cataract surgery]. / Epidémiologie de la contamination bactérienne oculaire en chirurgie de la cataracte.

PURPOSE: To evaluate anterior chamber (AC) bacterial contamination at the end of cataract surgery in a large series of patients, to determine the influence of operative technique on ocular contamination. METHODS: Retrospective study of 2,624 patients undergoing cataract extraction, 354 extracapsular cataract extraction (ECCE) and 2,270 phacoemulsification. Anterior chamber aspirates were performed on completion of surgery for microbiological studies. RESULTS: One hundred and thirty two patients (5%) had culture-positive anterior chamber aspirates. Coagulase-negative Staphylococcus, Propionibacterium sp. and Corynebacterium sp. were the most commonly isolated organisms. The AC contamination rates during ECCE (5.6%) and phacoemulsification (4.7%) were not statistically different. There was a statistically significantly higher risk of AC contamination in eyes receiving an intraocular lens (IOL) with polypropylene haptics (9.9%) than in eyes receiving the same IOL with polymethylmethacrylate haptics (4.4%). CONCLUSION: Surgical technique had no statistically significant effect on ocular contamination. Polypropylene haptics IOLs were associated with a higher risk of bacterial contamination.

[Intraocular contamination during cataract surgery according to surgical technique and type of implant]. / Contamination intra-oculaire au cours de la chirurgie de la cataracte selon la technique et l'implant utilisés.

PURPOSE: To determine wether the cataract extraction method and intraocular lens material affect bacterial contamination of the eye during surgery. METHODS: This retrospective study evaluated microbial contamination of the anterior chamber fluid in three group of patients. Group 1: extracapsular extraction and PMMA lens (354 cases). Group 2: phacoemulsification and PMMA lens (474 cases). Group 3: phacoemulsification and silicone lens with PMMA haptic (264 cases). RESULTS: Microbial contamination rate was in group 1: 5.65%, in group 2: 4.75%, and in group 3: 4.54%. The difference was not statistically significant (chi: 0.321). All contaminants were Gram positive. CONCLUSION: Bacterial contamination rate of the anterior chamber is similar during extracapsular extraction and phacoemulsification, and is not modified when using PMMA or silicone lens.

[Interest of typing methods to study Corynebacterium diphtheriae strains.]. / Apport des méthodes de typage dans l'étude des souches de Corynebacterium diphtheriae.

Corynebacterium diphtheriae is the causative agent of Diphtheria. This bacteria circulates throughout the world. Recently, two outbreaks occurred in New independent states (Russia, Ukraine...) and Algeria. Routine technics permit to study the strains of Corynebacterium diphtheriae : biotype, antibiotype, toxin gene detection. However, molecular biological tests (ribotyping, and pulsed field gel electrophoresis) are necessary to characterize these strains in the space and the time. The studies with international laboratories exchanges are recents and have permitted first results concerning the molecular epidemiology of C. diphtheriae strains.

[Necrotic skin lesions caused by pet rats in two teenagers]. / Lésions cutanées nécrotiques liées au Cowpox virus inoculé par des rats de compagnie.

We report 2 observations in young girls who, after exposure to domestic rats from the same pet shop, presented with inflammatory and necrotic skin wounds in the neck and face. Since lesions did not improve with antibiotic therapy, surgical excision of necrosis healed the wounds, with a 2nd intervention necessary in 1 patient. All bacteriological investigations appeared to be negative; finally, electron microscopy of excised subepidermal tissue and PCR characterization provided the diagnosis of cowpox virus (CPXV) infection. CPXV is part of the Orthopox virus genus, like variola virus, and is generally transmitted to humans by infected cats or rodents. CPXV infection should be kept in mind when macular, vesicular, or necrotic cutaneous wounds do not improve with antibiotics.

Orchiopexy with a thimble.

The use of a thimble to facilitate scrotal fixation of the testis is described. We performed 52 orchiopexies in 48 children with cryptorchidism using this simple technique with excellent results.

Kinetics of conversion of Neisseria gonorrhoeae to resistance to complement by cytidine 5'-monophospho-N-acetyl neuraminic acid.

Freshly isolated gonococci upon subculture are readily lysed by normal human serum although a few strains remain inherently resistant to the complement activity. The sensitive gonococci can be converted to serum resistance by incubation with a host derived factor referred to as cytidine 5'-monophospho-N-acetylneuraminic acid (CMP-NANA). These gonococci resist complement mediated killing due to their sialylation of an epitope structure on a component of lipo-oligosaccharide (LOS). In the present study, the kinetics of conversion to serum resistance by the action of sialyltransferase (STase) in Neisseria gonorrhoeae was followed with very low concentrations of CMP-NANA. This conversion could not be perceived at 2 x 10(-3) nmol.ml-1 but was fully attainable from 8 x 10(-3) to 2 x 10(-2) nmol.ml-1 CMP-NANA. When pretreated up to 100 min in presence of the very low concentration of 2 x 10(-3) nmol.ml-1, a potentiating effect on the conversion of gonococci by 2 x 10(-2) nmol.ml-1 was observed in relation to the time of preincubation. This action was abolished after exposure to a subinhibitory concentration of chloramphenicol (0.5 microgram.ml-1). The gonococci recovered their ability to convert to serum resistance following adequate washing. The potential for increase in STase activity should be of interest for understanding the conversion from a serum sensitive to a serum resistance state.

[Kinetics of sialylation of Neisseria gonorrhoeae by radiolabelled cytidine 5'monophospho-N-acetyl neuraminic acid]. / Cinétique de sialylation de Neisseria gonorrhoeae par l'acide cytidine 5'monophospho-n-acétyl neuraminique radio-marqué.

Neisseria gonorrhoeae (Strain A) induces a sialyl-transferase when treated with a very low concentration of cytidine 5'monophospho-N-acetyl neuraminic acid, 2 x 10(-3) nmol.ml-1, a concentration which is insufficient to produce an adequate resistance to human serum complement. The sialyl-transferase activity was detected by measurement of fixed 14C radio-labeled sialyl groups. Without this stimulation, there was practically no transfer of sialyl groups. The gonococcal sialyl-transferase could be considered inducible.

Helicobacter pylori infection: physiopathologic implication of N alpha-methyl histamine.

BACKGROUND/AIMS: In the gastric mucosa of Helicobacter pylori-infected subjects, we previously detected N alpha-methyl histamine (N alpha-MeHA), a minor catabolite of histamine and a potent agonist of histamine H3 receptors. The origin of N alpha-MeHA and its effects on gastric histamine and somatostatin in infected subjects were investigated. METHODS: Ten noninfected patients and 13 patients with intense colonization were compared. N alpha-MeHA content and its synthetic enzyme activity, N alpha-histamine methyltransferase, binding of [3H]N alpha-MeHA, histamine and somatostatin contents, and histidine decarboxylase activity were assayed in antral and fundic biopsy specimens and in cultured H. pylori strains. RESULTS: Gastric histamine and somatostatin contents as well as histidine decarboxylase activity were decreased in infected patients and were restored to normal after antimicrobial treatment. Both N alpha-MeHA and N alpha-histamine methyltransferase activity were present in the mucosa of infected patients and in cultured strains and were very low in noninfected patients or after eradication of H. pylori. [3H]N alpha-MeHA bound to gastric mucosa but not to cultured strains. The [3H]N alpha-MeHA specific binding sites were characterized as H3 receptors. The amount of bound [3H]N alpha-MeHA seemed correlated positively with somatostatin content and histidine decarboxylase activity and negatively with N alpha-MeHA content and N alpha-histamine methyltransferase activity. CONCLUSIONS: H. pylori is the main source of gastric N alpha-MeHA that may lower histidine decarboxylase activity and somatostatin content through H3 receptors.

Resistance of two strains of Streptococcus pneumoniae to pristinamycin associated with 16-membered macrolides.

Two strains of Streptococcus pneumoniae isolated from haemocultures show a phenotype resistance which has never been described within this species. This a is a dissociation between resistance and sensitivity within the macrolides group, associated with global resistance as regards pristinamycin (SA + SB).

Lactate enhancement of sialylation of gonococcal lipopolysaccharide and of induction of serum resistance by CMP-NANA is not due to direct activation of the sialyltransferase: metabolic events are involved.

Lactate enhances lipopolysaccharide (LPS) sialylation and induction of serum resistance in gonococci by CMP-NANA. To investigate whether the enhancement is due to a direct effect on the sialyltransferase, an improved extraction of the enzyme and a reliable quantitative assay were devised. Gonococci (strain F62) were disrupted in a French pressure cell and the bacterial membranes were extracted for 1 h at 37 degrees C with a detergent, NONIDET (1% v/v). The assay involved sialylation of LPS by CMP-14CNANA and scintillation counting of the labelled LPS after fixing it on filter paper strips by trichloracetic acid (TCA) and washing away unincorporated CMP-14CNANA. It was rapid, reproducible and, although the enzyme preparations contained endogenous LPS, was dependent upon added LPS for maximum activity. At 37 degrees C the rate was constant for up to 5 min and proportional to the concentration of extract in the assay. A wide range of concentrations of lithium-L-lactate did not enhance the activity of the extracted sialyltransferase. At concentrations above 22 microM, it was inhibitory. Pre-incubation of gonococci with lactate enhanced subsequent LPS sialylation and induction of serum resistance by CMP-NANA. Hence, the process whereby lactate enhances the effect of CMP-NANA is separate from the action of CMP-NANA itself. Both processes were inhibited by a sublethal concentration of chloramphenicol, indicating that metabolic events are required. Evidently, the enhancement process does not involve a direct activation of the sialytransferase.