The aim of this work was to determine the effects of a new mineral mix combined with a prebiotic on growth, mineral deposit and intestinal microflora using a milk-like vehicle.This study was performed with Sprague Dawley female rats separated into 7 groups.Group 1 was fed with a deficient diet on its mineral content, group 2, 3 and 4 were fed with normal diets on their mineral content during 28 days but group 2 was fed with a diet containing reference Ca, Fe and Zn sources and groups 3 and 4 with diets containing other Ca, Fe and Zn sources that were evaluated.Group 4 received additionally a diet containing a prebiotic.Groups 5, 6 and 7 were submitted to a depletion period of 14 days during which they were fed as group 1 and then to a repletion period of 14 days when they were fed with the same diets as group 2, 3 and 4 respectively.Initial and final body weight, average growth rate, liver and femur weight, iron and zinc liver content as well as calcium and zinc femur content were the parameters evaluated for the growth and mineral deposit analysis.Anaerobes, enterobacteria, lactobacilli and bifidobacteria recount was performed from feces samples collected on different treatment days.Mineral sources under study presented slightly better characteristics than the reference standard ones.Moreover, the combination with a prebiotic may produce some advantages related to mineral absorption and intestinal microflora composition as a bifidogenic effect was confirmed.

Lemierre's syndrome was described in 1936 as a severe oropharyngeal infection followed by septic thrombophlebitis of the internal jugular vein and disseminated metastatic infections. Cases occur typically in previously healthy young adults and children. Fusobacterium necrophorum is the main anaerobic bacterium implicated. We present a septic 2-month-old infant with mastoiditis, multiple sites of osteoarthritis and multiple subcutaneous abscesses. No underlying anatomic or immunologic abnormalities were identified. Fusobacterium necrophorum was recovered from blood and bone samples obtained intraoperatively. Treatment included anaerobic coverage and drainage of septic foci. The patient was discharged home on 35th hospital day with oral amoxicillin–clavulanic acid and he recovered without sequelae. This was the first case of Lemierre's syndrome in our hospital. We want to highlight the absence of jugular vein thrombophlebitis, the presence of mastoiditis as previous infection and the surprising appearance of this infection in an edentulous 2-month-old infant.

Anaerobes contribute to the severity and chronicity of infections that occur in and around the oral cavity. One of the factors involved in the pathogenesis of otitis media with effusion (OME) is the retrograde movement of bacteria from the oropharynx into the middle ear cavity. OME is one of the most common causes of hearing loss in children. We have used a PCR-based method to identify Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola andFusobacterium nucleatum in 65 middle ear effusion (MEE) samples obtained from paediatric patients seen for myringotomy and tube placement. DNA was extracted from MEE samples and PCR was initially done with DNA extracts by using the universal primers within the 16S rRNA gene sequence common to all bacterial species. The positive samples were further assessed with four species-specific primers. With the universal primers, 27 of 65 samples (41.5%) showed positive reaction indicating the presence of bacterial DNA. F. nucleatum was present in 10 out of 27 PCR-positive samples (37%) while one sample was positive for both T. denticola and F. nucleatum (3.7%). A. actinomycetemcomitans and P. gingivalis were not detected in any of the samples. The results of this study suggest that oral bacterial species may also play a role in the aetiopathogenesis of paediatric MEE.

Veillonella spp. are early colonizing inhabitants in the mouth. As part of studies on penicillin resistance among oral indigenous anaerobic microbiota in childhood, the aim of the present longitudinal study was to examine the emergence of resistant strains in Veillonella populations. Altogether 305 Veillonella isolates from saliva of 49 healthy infants followed from 2 to 24 months of age were examined for their in vitro susceptibility to penicillin G and, further, 20 penicillin-resistant isolates representing 5 MIC categories to ampicillin, amoxicillin, amoxicillin/clavulanate, cefoxitin, and β-lactamase production. In infants positive for oral Veillonella, the recovery rate of penicillin-resistant (MIC ≥2 μg/ml) strains increased with age up to 68%, however, most infants simultaneously harbored penicillin-susceptible strains. During the follow-up, the MIC50 increased from 0.5 μg/ml to 2 μg/ml. In addition to penicillin G, 8/20 strains also showed reduced susceptibility to ampicillin and/or amoxicillin but none produced β-lactamase. Our study suggests other mechanisms than enzymatic degradation of β-lactam ring for resistance of oral Veillonella to penicillin.

We evaluated an agar disc diffusion test for the detection of high-level (> or = 2000 mg/L) and moderately high-level resistance to gentamicin (MIC, > or = 128- < or = 1024 mg/L) and streptomycin (MIC, > or = 256- < or = 1024 micrograms/ml) with 70 clinical isolates of Enterococcus faecium. Results obtained using disks containing 120 micrograms gentamicin and 300 micrograms streptomycin were compared with MICs determined by an agar dilution method. Based on the scattergrams, the closest zone diameter correlations with MIC breakpoints were as follows: susceptible, > or = 16 mm; and resistant, < or = 10 mm, for both streptomycin and gentamicin. No major or very major errors were found with either aminoglycoside using these values. We conclude that agar disk diffusion test can be used to accurately detect high-level or moderately high-level gentamicin and streptomycin resistance in E. faecium.

Beta-lactamase-producing (Bla+) enterococci have been reported in three states and two countries. Pulsed-field gel electrophoresis was used to compare 14 Bla+ Enterococcus (Streptococcus) faecalis isolated from hospitalized patients in seven states and three continents. The restriction endonuclease digestion patterns of isolates from Connecticut, Massachusetts, Lebanon, and Argentina were all markedly different, indicating that these were different strains. However, isolates from Delaware, Texas, Pennsylvania (Philadelphia and Pittsburgh), Florida, and Virginia were similar, indicating that these isolates were derivates of a single strain. This conclusion was supported by hybridization using individual fragments as probes. Spread of Bla+ enterococci within the hospital setting was also demonstrated. These findings illustrate the value of pulsedfield gel electrophoresis for epidemiologic analyses and support the importance of identifying and containing organisms with new resistance properties in an effort to decrease their transmission to and from, as well as within, hospitals.

We conducted a prospective study in 87 household contacts of 51 children with hemolytic uremic syndrome to determine the frequency of infection with Shiga-like toxin-producing bacteria. Gastrointestinal tract symptoms occurred in only 1 of 87 contacts. Free fecal toxin was detected in 25 of 64 (39%) of the household members. Neutralization with specific antisera to Shiga-like toxins I and II (SLT-I, SLT-II) revealed that in 6 of these household contacts only SLT-I was present in stool, in 10 only SLT-II was present and in 9 both toxins were found. Thirty-three percent of the hemolytic uremic syndrome families in which 2 or more members were studied had more than 1 household member with free fecal toxin in stool. None of the household contacts was found to have E. coli O157:H7 in feces. Serum samples were available in 77 household contacts; 75% (58 of 77) had serum neutralizing titers of greater than or equal to 1:4 to 1 or both toxins. In those contacts for whom paired sera were available, seroconversion was found in 10 of 24 (42%). These data show that household contacts of children with hemolytic uremic syndrome are commonly colonized with Shiga-like toxin-producing E. coli and seroconversion to Shiga-like toxins occurs frequently in family members of children with hemolytic uremic syndrome.

A prospective study in 87 household contacts of 51 children with HUS was performed, with the aim of determining evidence of infection with Shiga-like toxin producing bacteria. Gastrointestinal tract symptoms were present in only 1/87 contacts. DNA hybridization studies of fecal E.coli isolates from 80 of these 87 contacts were positive in 6. Free fecal cytotoxin was detected in 25/64 (39%) of the household members. In 58 out of the 77 (75%) serum samples available in the household contacts, serum neutralizing titers of 1:4 to one or both toxins, was detected. Seroconversion was found in 10/24 (42%). These data show that household contacts of children with hemolytic uremic syndrome are commonly positive to Shiga-like toxin produced by E.coli. Seroconversion to these toxins occurs frequently in family members of children with hemolytic uremic syndrome.

Shiga-like toxin-producing Escherichia coli have been associated with hemorrhagic colitis and the hemolytic uremic syndrome (HUS). Because Argentina has the highest reported frequency of HUS in the world, Argentine children were prospectively studied during the HUS seasons for evidence of Shiga-like toxin-related diseases. On the basis of serology, fecal cytotoxin neutralization, stool cultures, and DNA hybridization of colony lysates, most children with HUS had evidence of infection with Shiga-like toxin-producing organisms. Children with spring-summer diarrhea also commonly (32%, confidence interval 18%-46%) had clear-cut evidence of such infection. No controls (children without gastrointestinal, renal, or hemolytic disease) had free fecal cytotoxin, positive cultures for E. coli O157:H7, or DNA probe-positive organisms; 20% of them had low serum titers of antibodies to Shiga-like toxins. E. coli O157:H7 was not common in either HUS or diarrhea patients. The high frequency of Shiga-like toxin-induced diarrhea in young children in Argentina probably explains the high incidence of HUS in this country and suggests that HUS is a relatively uncommon complication of Shiga-like toxin-related disease.

We conducted a prospective study to determine the frequency of SLT-related HUS and SLT-related diarrhea in Argentinian children. Fecal toxin measured in a (3H) Hela cell system was detected in 10/31 (32%) HUS patients, in 7/31 (22.6%) age - season matched children with diarrhea (CD) and in 0/19 (0%) healthy children (p<0.025). Neutralization with specific antisera showed that in 5 HUS patients and in 4 CD only SLT-I was present and in 5 HUS and 3 CD SLT-I and SLT-II were found. DNA hybridization was used to screen 555 E. coli strains isolated from these patients for SLT-I and SLT-II. Three HUS and 3 CD were DNA probe positive for SLT-II and 1 HUS case was DNA probe positive for both toxins. E. coli 0157:H7 were detected in 2 CD and in 1 HUS patient. Fifty-one percent (21/41) HUS patients, 21% (10/47) CD and 5% (1/19) healthy children had serum neutralizing titers of ≥ 1:4 to shigatoxin (p<0.0005). These date show that HUS is associated with SLT-producing E. coli and suggest that the high frequency of HUS in Argentina is related to the common occurrence of SLT-associated diarrhea.