Cerebral abscess caused by Capnocytophaga spp in an immunocompetent subject: case report.

Capnocytophaga spp are Gram-negative bacteria commonly identified as oral saprophytes of humans, dogs and cats; they rarely cause invasive infections in immunocompetent subjects. This case report is about a rare case of cerebral abscess caused by Capnocytophaga spp in an immunocompetent subject who had no risk factors for Capnocytophaga invasive infections (oral alterations, traumatic or iatrogenic lesions of pharynx and/or oesophagus, recent dog bite). We also report Capnocytophaga spp naturally resistant to metronidazole, this being the cause of inefficacy of this drug usually included in empiric chemotherapy of cerebral abscess.

Group A streptococcal infections: trend and strain emm typing in an area of central Italy, 1985-2002.

A retrospective study of group A streptococcal (GAS) infections was performed for the period 1985-2002 in an area of central Italy. Although very severe diseases such as streptococcal toxic shock syndrome (STSS) were observed, a general increase in invasive infections was not found. Isolates of GAS were classified by M protein genotyping (emm typing) and analysed according to their origin from invasive and non-invasive infections. The predominant emm types were types 1, 4 and 12, followed by types 3, 6 and 28. During the study period the proportion of isolates of types 1 and 12 fell, while other types (3, 6, 22, 28 and 77) appeared. Isolates from invasive and non-invasive infections shared several emm types; however, most invasive strains belonged to five types only (types 1, 4, 12, 28 and 77), while non-invasive isolates were generally more heterogeneous.

Epidemiology of streptococcus group A in school aged children in Pemba.

BACKGROUND: In Pemba (Zanzibar) all the risk factors which favour Group A Streptococci spreading, infections and late sequelae are present, though GAS epidemiology is unknown. OBJECTIVE: To determine the prevalence of GAS pharyngeal carriers among school-aged-children. DESIGN: Community-based cross sectional study, carried out at the end of the dry season (January-February 2001). SETTING: Eight primary schools over the four Pemba districts were included in the study. SUBJECTS AND METHODS: Two thousand two hundred and eighty six children aged 7-10 years were selected by random sampling and submitted to throat-swab after informed consent. Swabs were processed according to the "Lennette Manual of Clinical Microbiology" 7th Ed. Isolated were tested for antibiotic susceptibility toward penicillins, erythromycin, clindamycin, josamycin, cloramphenicol, levofloxacin, rifampin and tetracyclines. RESULTS: Twenty seven point six percent of school-aged children harboured beta-haemolytic Streptococci in their pharynx; most of the isolates were serologically identified as non Group A streptococci group C and G represented more than 70% of all strains, 38.8% of whom were identified as group G; the prevalence of group A streptococci carriers among healthy children all over the island was 8.6%; group A streptococci isolates were sensitive to all the antibiotic tested, except tetracyclines, towards which 83.2% of strains were resistant. CONCLUSION: This is the first research in the field of bacteriology carried out in Pemba. According to the epidemiology of group A streptococci and to the environmental and underlying factors which predispose to late group A streptococci sequelae, we suggest to consider antibiotic treatment for children presenting with sore throat with fever and swollen cervical lymphonodes without cough or coryza.

Sources and mechanisms of inorganic carbon transport for coral calcification and photosynthesis.

The sources and mechanisms of inorganic carbon transport for scleractinian coral calcification and photosynthesis were studied using a double labelling technique with H(14)CO(3) and (45)Ca. Clones of Stylophora pistillata that had developed into microcolonies were examined. Compartmental and pharmacological analyses of the distribution of(45)Ca and H(14)CO(3) in the coelenteron, tissues and skeleton were performed in dark or light conditions or in the presence of various seawater HCO(3)(-) concentrations. For calcification, irrespective of the lighting conditions, the major source of dissolved inorganic carbon (DIC) is metabolic CO(2) (70-75% of total CaCO(3) deposition), while only 25-30% originates from the external medium (seawater carbon pool). These results are in agreement with the observation that metabolic CO(2) production in the light is at least six times greater than is required for calcification. This source is dependent on carbonic anhydrase activity because it is sensitive to ethoxyzolamide. Seawater DIC is transferred from the external medium to the coral skeleton by two different pathways: from sea water to the coelenteron, the passive paracellular pathway is largely sufficient, while a DIDS-sensitive transcellular pathway appears to mediate the flux across calicoblastic cells. Irrespective of the source, an anion exchanger performs the secretion of DIC at the site of calcification. Furthermore, a fourfold light-enhanced calcification of Stylophora pistillata microcolonies was measured. This stimulation was only effective after a lag of 10 min. These results are discussed in the context of light-enhanced calcification. Characterisation of the DIC supply for symbiotic dinoflagellate photosynthesis demonstrated the presence of a DIC pool within the tissues. The size of this pool was dependent on the lighting conditions, since it increased 39-fold after 3 h of illumination. Passive DIC equilibration through oral tissues between sea water and the coelenteric cavity is insufficient to supply this DIC pool, suggesting that there is an active transepithelial absorption of inorganic carbon sensitive to DIDS, ethoxyzolamide and iodide. These results confirm the presence of CO(2)-concentrating mechanisms in coral cells. The tissue pool is not, however, used as a source for calcification since no significant lag phase in the incorporation of external seawater DIC was measured.

Effect of caulerpenyne, a toxin extracted from Caulerpa taxifolia on mechanisms regulating intracellular pH in sea urchin eggs and sea bream hepatocytes.

The proliferation of the green marine alga Caulerpa taxifolia in the Mediterranean led us to investigate the toxic effects on marine organisms of caulerpenyne (Cyn), the major secondary metabolite synthesized by the alga. This study was performed on sea urchin eggs (Paracentrotus lividus) and isolated hepatocytes from the sea bream (Sparus aurata), in which accumulation of the toxins by metabolic processes may be of significance. Cyn provoked an acidification of seawater containing both unfertilized and fertilized eggs, as revealed by a titrable efflux of protons. The pHi in unfertilized eggs continuously increased in the presence of Cyn, whereas there was a biphasic response in both fertilized eggs and isolated hepatocytes, with a decrease of the pHi followed by recovery to the initial value. Cyn inhibited the accumulation of 14C-methylamine in acidic granules present in the cortical zone of sea urchin eggs. Dicyclocarbodiimide (DCCD), a well-known H(+)-ATPase inhibitor, provoked a similar inhibition. Both molecules increased pH in the acidic compartments of isolated bream hepatocytes. These results suggest that Cyn inhibits intracellular sequestration of protons and thus liberates protons into the cell cytoplasm from which they leak toward the extracellular medium.