Nutritionally variant streptococci from corneal ulcers in horses.
Of 24 isolates of nutritionally variant streptococci recovered from equine corneal ulcers, 22 were tested for growth requirements, physiological and biochemical reactions, and susceptibility to different antimicrobial agents. Satisfactory growth was obtained by supplementing blood agar and Todd-Hewitt broth with pyridoxal hydrochloride, and all of the media for the culture and the biochemical testing were supplemented with 0.002% of this substance. Biochemical patterns of 12 of the isolates resembled those of two viridans streptococcal species, Streptococcus intermedius and Streptococcus constellatus. Patterns of 10 isolates did not resemble those of any recognized viridans species. All of the isolates were inhibited by less than or equal to 0.25 microgram of erythromycin per ml, less than or equal to 4 micrograms of chloramphenicol per ml, and less than or equal to 4 micrograms of gentamicin per ml, and all but two were inhibited by less than or equal to 0.1 microgram of penicillin per ml.
Abstract in english Streptococcus constellatus is a commensal microorganism in man but may cause infections in different locations. We report a 59 years old male with severe sequelae of a previous cerebrovascular accident that consulted in the emergency room for fever of 15 days of evolution. A right empyema was diagnosed. The bacteriological culture of the effusion disclosed the presence of Streptococcus constellatus and two anaerobic strains (Prevotella intermedia and Fusobacterium urealyt (more) icus). The patient was treated with a pleural drainage and received ceftriaxone and clindamycin during six weeks. He was discharged in good conditions and is asymptomatic after eight months of follow up (Rev Méd Chile 2006; 134: 1030-2)
Presumed Hydrogen Sulfide-Mediated Neurotoxicity Following Streptococcus Anginosus Group Meningitis.
Hydrogen sulfide (H2S) is an environmental toxicant and gaseous neurotransmitter. It is produced enterically by sulfur-reducing bacteria and invasive pathogens including Streptococcus anginosus group, Salmonella and Citrobacter. We describe putative focal H2S neurotoxicity following S. constellatus meningitis, treated with adjunctive sodium nitrite and hyperbaric oxygen therapy. PMID:23014355
A 56-year-old woman was admitted because of a high fever, right ptosis, chemosis, proptosis and ocular muscle palsy. Cranial MRI revealed a cavernous sinus thrombosis and a subarachnoid abscess. Carotid angio-gram demonstrated marked stenosis as well as aneurismal formation of the right internal carotid artery at the intracavernous portion. Chest radiograph showed bilateral multiple pulmonary nodules, some of which contained a cavity. Blood culture was positive for Streptococcus constellatus. She was diagnosed with septic cavernous sinus thrombosis complicated by narrowing of the internal carotid artery, subarachnoid abscess and multiple pulmonary septic emboli. She recovered with partial ocular sequelae as a result of seven weeks of intravenous antimicrobial therapy.
Some Characteristics of Rice Paper of Vietnamese Traditional Food (Vietnamese Spring Rolls)
Rice papers made of non-glutinous rice are a common food item in Vietnam and Thailand. Called as Banh Da Nem in Vietnam, rice papers are used very often in the making of a traditional dish called Nem, i.e., Vietnamese spring rolls. The amino acid content in the rice papers extracted with water was found to be 2 to 3 fold higher than that in cooked rice, showing that the protein was resolved by microbial enzymes during the rice paper processing. Among organic acids, Iactic acid is most common in rice papers, indicating that lactic bacteria is involved in the manufacturing. Many Gram-positive bacteria: Streptococcus constellatus, Streptococcus acidominimus, Staphylococcus capitis, Lactobacillus curvatus, Lactobacillus salivarius, and Gram-negative bacteria: Enterobacter cloacae, Klebsiella sp., Pseudomonas sp., along with wild type yeast were isolated from the milled-rice.
Infected Papillary Fibroelastoma Attached to the Atrial Septum
A 61-year-old woman had intermittent fever of 2 months' duration following a dental extraction. On admission, her body temperature was 39.2°C. A mid-systolic murmur was heard at the apex on ausculation. A 2-dimensional echocardiogram revealed a mobile, heavy stick-like mass with vegetation (5.0×1.5 cm) attached to the left atrial septum. Multiple blood cultures grew Streptococcus constellatus. On diagnosis of an infected left atrial myxoma, antibiotics were administered daily and 4 weeks later, the left atrial tumor was resected. The tumor was 5.3 cm long, 1.5 cm in diameter at the inter-atrial wall and had vegetation on the free edge. On microscopic examination, colonies of Gram-positive cocci were found in the thrombus, on the papillary fibroelastoma. After treatment with antibiotics for a further 4 weeks, the patient was discharged. This is the first report of infected papillary fibroelastoma. (Circ J 2002; 66: 305 - 307)
Bacterial viability on surface-modified resin-based dental restorative materials
The purpose of the present investigation was to investigate the viability of early colonizers on the surfaces of resin-based dental restorative materials modified with low-surface tension active agents in comparison with the unmodified material. A novel polymeric sorption material, loaded with two low-surface tension @c"L active agents (hydroxyfunctional polydimethylsiloxane and polydimethylsiloxane) or a polymerizable active agent (silicone polyether acrylate), was used to modify commonly formulated experimental dental resin composites. The non-modified resin was used as the standard (ST). The viability of Actinomyces naeslundii, Actinomyces viscosus, Streptococcus mitis, Streptococcus oralis, and Streptococcus sanguinis on water-stored, polished, and human saliva pellicle-coated specimen...
PROPERTIES OF PROTEINASE FROM STREPTOCOCCUS FAECALIS VAR. LIQUEFACIENS1
Bleiweis, Arnold S. (The Pennsylvania State University, University Park), and Leonard N. Zimmerman. Properties of proteinase from Streptococcus faecalis var. liquefaciens. J. Bacteriol. 88:653–659. 1964.—The extracellular group D streptococcal proteinase is inactivated by chelating agents [ethylened...
Streptococcus pneumoniae is a common cause of respiratory tract infections (RTIs). The prevalence of Streptococcus pneumoniae strains with reduced susceptibility to antimicrobial agents has dramatically increased worldwide. Susceptibility to nine antimicrobial agents and serotypes were determined among 1,644 Streptococcus pneumoniae strains isolated from patients with RTIs in the Tohoku district of Japan from October to December every year from 1998 to 2007. The prevalence of penicillin G-nonsusceptible Streptococcus pneumoniae (PNSP) strains increased gradually from 48.5% in 1998, reached a statistical peak in 2004 (65.1%) and then decreased to 51.5% in 2007. Streptococcus pneumoniae strains with each serotype 3, 6, 19 and 23 were constantly detected, and the distribution of these serotypes in PNSP strains did not significantly change during the study period. A trend of Streptococcus pneumoniae strains nonsusceptible to other ?-lactams tested was similar to that of PNSP strains, except for cefditoren, to which the resistance rate was < 20% throughout the analysis period. The prevalence of strains nonsusceptible to erythromycin and minocycline were consistently > 60%. Almost all penicillin G-resistant Streptococcus pneumoniae (PRSP) strains were resistant to both erythromycin and minocycline throughout the analysis period. The prevalence of strains resistant to fluoroquinolones tested were < 3% over the study period. Our longitudinal surveillance demonstrated for the first time that decreased prevalence of both ?-lactam- and multidrug-resistant strains has been occurring since 2004 in a region of Japan. Careful monitoring of antimicrobial susceptibility of Streptococcus pneumoniae should be continued.
Abstract in portuguese Este trabalho foi desenvolvido com o objetivo de avaliar a atividade in vitro do extrato alcoólico de própolis, contra agentes da mastite bovina, comparando-o aos principais antimicrobianos utilizados no tratamento convencional. Foram utilizados 36 isolados coagulase-positivos de Staphylococcus sp. e 27 isolados de Streptococcus sp.; 94,4% dos Staphylococcus sp. e 85,2% dos Streptococcus sp. foram susceptíveis ao extrato de própolis. Abstract in english The present study aimed to determine the in vitro activity of propolis extract, comparing it to the most common antibacterial drugs against bovine mastitis bacterial agents. Thirty-six isolates of coagulase-positive Staphylococcus sp. and twenty-seven of Streptococcus sp. were analyzed. Coagulase-positive Staphylococcus (94.4%) and Streptococcus sp. (85.2%) showed susceptibility to propolis extract.
A multicentre resistance surveillance study [Community-Acquired Respiratory Tract Infection Pathogen Surveillance (CARTIPS)] investigating the susceptibilities of 2963 clinical isolates of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Klebsiella pneumoniae, meticillin-susceptible Staphylococcus aureus (MSSA) and Streptococcus spp. from Asia against 12 antimicrobial agents was undertaken from 2009 to 2010. Based on the breakpoints for oral penicillin V recommended by the Clinical and Laboratory Standards Institute, the prevalence of penicillin-non-susceptible S. pneumoniae (PNSSP) ranged from 46% to 100%. Azithromycin and clarithromycin exhibited variable resistance rates of 0-88% against S. pneumoniae, 0-57% against MSSA and 0-76.5% against Streptococcus spp. iso...
Streptococcus gordonii septic arthritis : two cases and review of literature.
ABSTRACT: BACKGROUND: Despite advances in antimicrobial and surgical therapy, septic arthritis remains a rheumatologic emergency that can lead to rapid joint destruction and irreversible loss of function. In adults, Staphylococcus aureus is the most common microorganism isolated from native joints. Streptococcus gordonii is a prominent member of the viridans group of oral bacteria and is among the bacteria most frequently identified as being primary agent of subacute bacterial endocarditis. To the best of our knowledge, Streptococcus gordonii has not yet been described as agent of septic arthritis.Case PresentationWe describe here two cases of septic arthritis due to Streptococcus gordonii. It gives us an opportunity to review epidemiology, diagnosis criteria and management of septic arthritis. CONCLUSION: Although implication of S. gordonii as aetiologic agent of subacute endocarditis is well known, this organism is a rare cause of septic arthritis. In this case, the exclusion of associated endocarditis is warranted. PMID:22974507
E Test: a novel technique for antimicrobial susceptibility testing
Abstract in portuguese Descrevemos a aplicabilidade do E test (AB Biodisk, Solna, Suécia), um novo método para a determinação das concentrações inibitórias mínimas de agentes antimicrobianos contra bactérias. Apresentamos uma revisão da literatura e nossa experiência na utilização do E test na determinação da suscetibilidade de Xanthomonas maltophilia, Streptococcus viridians contra oito diferentes drogas. Abstract in english We describe the applicability of the E test (AB Biodisk Solna, Sweden), a new method for determining minimum inhibitory concentrations of antimicrobial agents against bacteria. This report is based on the literature review and on our own experience using the E test for susceptibility testing of the Xanthomonas maltophilia, Streptococcus pneumoniae and Streptococcus viridans group against eight different drugs.
In the last years, researches developed with biosurfactants for application in the medical area have been revealing the promising biological activities of these biomolecules. In this work the antimicrobial and anti-adhesive properties of a biosurfactant Rufisan isolated from the yeast Candida lipolytica UCP 0988, growth in a medium supplemented with ground nut refinery residue was determined against several microorganisms. The biosurfactant was able to reduce the water surface tension from 70 to 25.3 mN/m and showed a critical micelle concentration (CMC) of 0.03%. The biosurfactant was isolated after 72 h of fermentation and was tested in concentrations varying from 0.75 to 12 mg/l. The highest antimicrobial activities were observed against Streptococcus agalactiae, Streptococcus mutans, Streptococcus mutans NS, Streptococcus mutans HG, Streptococcus sanguis 12, Streptococcus oralis J22 at a concentration superior to the biosurfactant critical micelle concentration. Moreover, the biosurfactant showed anti-adhesive activity against most of the microorganisms tested. As far as we know, this is the first compilation of data on antimicrobial and anti-adhesive activities of a biosurfactant obtained from a Candida strain against such a broad group of microorganisms. The results obtained in this work showed that the biosurfactant from C. lipolytica is a potential antimicrobial and/or anti-adhesive agent for several biomedical applications. PMID:21247740
The major causative agents of bacterial meningitis, Haemophilus influenzae serogroup B, Neisseria meningitidis serogroups B and C, Klebsiella pneumoniae, Streptococcus pneumoniae, and two types of Escherichia coli, were cultured in a modified chemically defined Catlin medium and in a commercial vers...
A Novel Use of a Bacteriophage Lysin, PlyC, as a Disinfectant against Streptococcus equi
Streptococcus equi is the causative agent of a purulent infection in horses known as equine strangles and is transmitted through shedding of live bacteria from nasal secretions and abscess drainage. There are no accepted cures for equine strangles with conventional antibiotics being only partially ...
The Use of Dexamethasone in Bacterial Meningitis in Children and Adults: A Retrospective Analysis
Bacterial meningitis is a life-threatening illness that results from bacterial infection of the meninges and is associated with high mortality and morbidity rate, especially when the Streptococcus pneumoniae is the causative agent. Dexamethasone as adjunctive therapy to antibiotics does not influenc...
Group A Streptococcus (GAS) is a common causative agent of pharyngitis, but the role of GAS in otitis media is underappreciated. In this study, we sought to test the hypothesis that GAS colonizes the middle ear and establishes itself in localized, three-dimensional communities representative of biof...
Streptococcus pneumoniae is the main causal agent of pathologies that are increasingly resistant to antibiotic treatment. Clinical resistance of S. pneumoniae to ?-lactam antibiotics is linked to multiple mutations of high molecular mass penicillin-binding proteins (H-PBPs), essential enzymes involv...
By using the selective capture of transcribed sequences (SCOTS) approach, we identified 28 genes preferentially expressed by the major swine pathogen and zoonotic agent Streptococcus suis upon interaction with porcine brain microvascular endothelial cells. Several of these genes may be considered ne...
Streptococcus pyogenes meningitis in children: report of two cases and literature review
Abstract in english Streptococcus pyogenes meningitis (SPM) occurs sporadically, even with the increase of invasive streptococcal disease observed in the past years. We reported two cases of SPM in infants to alert pediatricians for the possibility of this agent as a cause of meningitis in previously healthy children.
Numerous microbial pathogens exploit complement regulatory proteins such as factor H (FH) and factor H-like protein 1 (FHL-1) for immune evasion. Fba is an FHL-1 and FH binding protein expressed on the surface of the human pathogenic bacterium, Streptococcus pyogenes, a common agent of pharyngeal, s...
Some microbial pathogens utilize human complement regulatory proteins, such as factor H (FH) and factor H-like protein 1 (FHL-1), for immune evasion. FbaA is an FHL-1 and FH binding protein expressed on the surface of group A streptococcus (GAS), a common agent of pharyngeal, skin, and soft tissue i...
Understanding the burden of pneumococcal disease in adults
Abstract Streptococcus pneumoniae causes different types of acute, invasive and non-invasive clinical infections, being the most frequently detected pathogen responsible for community-acquired pneumonia. Pneumococcal pneumonia is accompanied by bacteraemia in 10-30% of cases. Streptococcus pneumoniae is gaining resistance to the in vitro activity of several antimicrobial agents and, even if questions remain regarding the clinical impact of this phenomenon, more and more reports indicate that antibiotic resistance can lead to more treatment failures if not higher mortality. Use of the 23-valent anti-pneumococcal vaccine appears to offer subpotimal protection against pneumococcal disease, particularly among high-risk adult populations. Vaccination against S.-pneumoniae with new conjugate vac...
For the purpose of nationwide surveillance of the antimicrobial susceptibility of bacterial respiratory pathogens collected from patients in Japan, the Japanese Society of Chemotherapy conducted a third year of nationwide surveillance during the period from January to April 2008. A total of 1,097 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 987 strains (189 Staphylococcus aureus, 211 Streptococcus pneumoniae, 6 Streptococcus pyogenes, 187 Haemophilus influenzae, 106 Moraxella catarrhalis, 126 Klebsiella pneumoniae, and 162 Pseudomonas aeruginosa). A total of 44 antibacterial agents, including 26 ?-lactams (four penicillins, three penicillins in combination with ?-lacta...
The antimicrobial and cytotoxic effects of sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) were evaluated and compared in vitro. The minimal inhibitory concentration and minimal bactericidal concentration of NaOCl and NaDCC were tested for Streptococcus sobrinus, Streptococcus salivarius, Enterococcus faecalis, and Streptococcus mutans. The cytotoxic effect was assessed by using human fibroblast tissue culture. Survival rate was assessed by a protein determination method. Results showed that the minimal inhibitory concentration and minimal bactericidal concentration values of NaOCl and NaDCC for the tested bacteria were in a similar range. NaDCC in concentrations higher than 0.02%, and NaOCl in concentrations higher than 0.01% were lethal to fibroblasts. In conclusion it seems that both agents were very effective in killing bacteria, and their cytotoxicity to fibroblasts in tissue culture was similar. PMID:11485267
Uterine microbiology, antimicrobial susceptibility and endometrial cytology were investigated in a total of 51 mares with fertility problems from 16 different stud farms in Serbia. Uterine cultures were performed after collection with a double guarded uterine swab, and endometrial cytology was evaluated after collection of endometrial cells with a special device (cytology brush). In 21 of 51 mares, at least one bacterial species was isolated from the uterus; the most frequent were Streptococcus equi subsp. zooepidemicus (13 isolates) and E. coli (four isolates). All isolates of Streptococcus equi subsp. zooepidemicus were susceptible to penicillin. Results from endometrial cytology were inconsistent; in 17 animals with positive bacteriological culture, cytology was not altered. It can be concluded that in Serbia, as in many other contries, Streptococcus equi subsp. zooepidemicus is the main cause for equine endometritis. It can be easily diagnosed by uterine culture but endometrial cytology does not always prove the existence of an endometrial infection with this agent. PMID:21038807
Mastitis is one of the most frequent infectious diseases in dairy cattle and is a reason for antimicrobial drug usage in dairy cows. The bacteria involved in bovine mastitis are mainly Streptococcus spp., Staphylococcus spp., and coliforms. The aim of this study was to determine antimicrobial resistance among Streptococcus spp. isolated from bovine mastitis milk. Antimicrobial resistance in Strep. uberis (n=227), Strep. dysgalactiae (n=49), and Strep. agalactiae (n=3) was determined for 9 antimicrobial agents using the broth microdilution method in accordance with Clinical and Laboratory Standards Institute recommendations. Of all Streptococcus spp., 13% were multidrug resistant. The rate of multidrug resistance was higher among Strep. uberis (15%) than among Strep. dysgalactiae (6%) and S...
Otitis media: conceptos actuales
Abstract in spanish La otitis media aguda es uno de los motivos más frecuentes de consulta en la edad pediátrica. Los gérmenes que con mayor frecuencia se aíslan en el oído medio de estos pacientes son el Streptococcus pneumoniae, el Haemophilus influenzae, la Moraxella catarrhalis y el Streptococcus pyogenes. El patrón de resistencia antibiótica de estas bacterias varía dependiendo de la región geográfica. y es la base fundamental para establecer recomendaciones terapéuticas. El (more) análisis en Costa Rica. de la microbiología de la otitis media aguda, otitis media recurrente y otitis media catalogada como falla terapéutica, sugiere que la amoxicilina en una dosis de 50 mg/Kg/día por 10 días, debe ser considerada el antibiótico de primera línea en los casos de otitis media aguda. En los pacientes con otitis media recurrente, falla antimicrobiana o cuando se sospeche la presencia de un Streptococcus pneumoniae resistente a la penicilina, se debe considerar el uso de amoxicilina en dosis más elevadas, amoxicilina con ácido clavulánico, macrólidos o ceftrlaxona. Abstract in english Otitis media is one of the most common causes of consultation among the pediatric population. The pathogens most frequently isolated from middle ear fluid are Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pyogenes. Antimicrobial resistance patterns vary by region and their knowledge is considered important in order to achieve proper antimicrobial selection. In Costa Rica the microbiology of patients with acute, recurrent and tte (more) attnent failure otitis media has been recently analyzed. The results of these studies indicate that amoxicillin at 50 mg/kg/day for 10 days should be considered first line of therapy for patients with acute otitis media. In patients with recurrent otitis media, therapeutic failures or in patients at risk of having a penicillin non-susceptible Streptococcus pneumoniae, one of the second line agents should be considered.
The macrolide ketocarbonic acid carolacton (1) was isolated from the myxobacterium Sorangium cellulosum, strainSo ce960, because of its antibiotic activity. Subsequently, carolacton (1) was discovered to be a highly potent agent against biofilms containing the caries- and endocarditis-associated bacterium Streptococcus mutans. The 2D structure of 1 was elucidated by HRMS, IR and 2D NMR spectroscopy. Initially, the stereogenic centres were determined by chemical derivatization in combination with computional methods and finally verified by X-ray analysis.
By using the selective capture of transcribed sequences (SCOTS) approach, we identified 28 genes preferentially expressed by the major swine pathogen and zoonotic agent Streptococcus suis upon interaction with porcine brain microvascular endothelial cells. Several of these genes may be considered new S. suis candidate virulence factors. Results from this study demonstrate the suitability of SCOTS for the elucidation of gene expression in streptococcal species and may contribute to a better understanding of the pathogenesis of S. suis infections. PMID:17483264
Abstract in portuguese Foram examinados 206 "swabs" cervicais e uterinos de éguas de várias raças, de diversas regiões do Estado de Minas Gerais, durante o período de 1986 a 1996. Cerca de 164 "swabs" foram positivos para a presença de microrganismos causadores de endometrites. Streptococcus equi subsp. zooepidemicus (25,7%) e Escherichia coli (15,1%) foram os principais agentes infecciosos isolados. Outros microrganismos presentes foram: Staphylococcus aureus (9,2%), Streptococcus alfa-h (more) emolítico (9,2%), Pseudomonas aeruginosa (3,9%), Staphylococcus coagulase negativo (6,3%), Bacillus spp. (1,9%), Rhodococcus equi (3,4%) e Proteus mirabilis (1,5%). As provas de susceptibilidade aos antimicrobianos revelaram que amicacina e gentamicina (70,2%), ampicilina (59,5%) e cloranfenicol (59,5%) foram os antibióticos de maior ação in vitro contra os microrganismos isolados. Abstract in english This study examined 206 cervical and uterine swabs collected from infected mares from herds in the Minas Gerais State, Brazil, from 1986 to 1996. Amongst 164 successful isolations, 25.7% were identified as Streptococcus equi, subsp. zooepidemicus, and 15.1% as Escherichia coli, both considered the most important isolates. Other bacteria found included Staphylococcus aureus (9.2%), Streptococcus alpha-hemolytic (9.2%), Pseudomonas aeruginosa (3.9%), coagulase negative Stap (more) hylococcus (6.3%), Bacillus spp. (1.9%), Rhodococcus equi (3.4%) and Proteus mirabilis (1.5%). The antibiotic susceptibility tests revealed amikacin and gentamicin (70.2%), ampicillin and chloramphenicol (59.5%) as the most effective in vitro antibiotics against these microorganisms.
Bacteriología y sensibilidad antibiótica en otitis media aguda
Abstract in spanish Introducción. La otitis media aguda es uno de los diagnósticos más frecuentes en niños menores de dos años. Objetivos. Los objetivos de este estudio fueron conocer los microrganismos más frecuentes causantes de otitis media aguda y su sensibilidad antibiótica; y valorar la prevalencia de los agentes patógenos según la edad de los pacientes. Población, material y métodos. El trabajo se llevó a cabo mediante el análisis de 249 muestras de oído medio obtenidas (more) por timpanocentesis en 174 niños que asistieron al Servicio de Otorrinolaringología Infantil de la Clínica Universitaria Reina Fabiola con diagnóstico de otitis media aguda en el período comprendido entre los años 2001-2004. El grupo de pacientes incluyó ambos sexos (91 varones; 83 mujeres) entre las edades de 18 días y 24 meses con un promedio de edad de 9 meses. Además, se dividieron en dos grupos: niños menores de 6 meses y niños mayores de 6 meses. Los perfiles de sensibilidad antibiótica de los agentes etiológicos más frecuentes se estudiaron de acuerdo con los principios establecidos por el Comité Nacional para Estandarizaciones de Laboratorios Clínicos (Nacional Comittee for Clinical Laboratory Standards). Resultados. El Streptococcus pneumoniae y el Haemophilus influenzae surgieron como los agentes predominantes. Estos resultados fueron similares a los encontrados en previas publicaciones. El Haemophilus influenzae predominó en los niños menores de 6 meses y el Streptococcus pneumoniae en los mayores de esa edad. Con respecto a la sensibilidad a la penicilina, el Streptococcus pneumoniae presentó un 77,6% de sensibilidad y el Haemophilus influenzae, un 85,5%. Conclusión. El Streptococcus pneumoniae fue el germen más frecuente en los niños mayores de 6 meses y el Haemophilus influenzae en los menores de esa edad. Abstract in english Introduction. Acute otitis media is one of the most frequent diagnoses in children under two years old. Objectives. The aims of this study were: to identify the most common microorganisms that cause AOM and their antibiotic sensitivity, and evaluate the prevalence of pathogenic agents according to patients ages. Population, material and methods. This study was based on the analysis of 249 middle-ear samples obtained by tympanocentesis in 174 children with a diagnosis of a (more) cute otitis media who attended to the Pediatric Otolaryngology Department of the "Clínica Reina Fabiola" at the Catholic University of Córdoba, Argentina, between 2001-2004. The group of patients comprised 91 males and 83 females between 18 days and 24 months of age (average age: 9 months). These patients were divided into two other groups: 1) children under 6 months of age, and 2) children over 6 months of age. Results. Predominant agents were Streptococcus pneumoniae and Haemophilus influenzae. These results were similar to those found in previous publications. Haemophilus influenzae was predominant in children under 6 months and Streptococcus pneumoniae prevailed in older children. With regard to penicillin susceptibility pattern, Streptococcus pneumoniae had a response of 77.6% and Haemophilus influenzae, of 85.5%. The patterns of antibiotic sensitivity of the most frequent etiological agents were studied according to the principles of the National Committee for Clinical Laboratory Standards. Conclusion. A long-term longitudinal follow-up will allow us to detect the emergence of resistant strains and new etiological agents. By these means it will be possible to improve the therapeutic efficacy and reduce complications and costs of this frequent pathology.
Herbal medicines that block bacteria or cancer cells from adhering to their target cells offer a novel therapeutic approach. These medicines can potentially help prevent and treat a range of infections or cancers. Vaccinium macrocarpon (cranberry) is the best-studied of these medicines. It has been shown to be useful both in prevention and treatment of urinary-tract infection in some patients. There is growing interest in using cranberry or its close relatives?V. angustifolium or V. corymbosum (blueberry); V. myrtillus (bilberry); and V. ovalifolium, V. ovatum, or V. parvifolium (huckleberry)?to block Helicobacter pylori and Streptococcus spp. adhesion. Camellia sinensis (tea) also has promise as an antiadhesion agent, particularly against Streptococcus mutans. Other herbs with antiadhesio...
Understanding the burden of pneumococcal disease in adults.
Clin Microbiol Infect 2012; 18 (Suppl. 5): 7-14 ABSTRACT: Streptococcus pneumoniae causes different types of acute, invasive and non-invasive clinical infections, being the most frequently detected pathogen responsible for community-acquired pneumonia. Pneumococcal pneumonia is accompanied by bacteraemia in 10-30% of cases. Streptococcus pneumoniae is gaining resistance to the in vitro activity of several antimicrobial agents and, even if questions remain regarding the clinical impact of this phenomenon, more and more reports indicate that antibiotic resistance can lead to more treatment failures if not higher mortality. Use of the 23-valent anti-pneumococcal vaccine appears to offer subpotimal protection against pneumococcal disease, particularly among high-risk adult populations. Vaccination against S.?pneumoniae with new conjugate vaccines seems to be the most promising field for real improvement in the management of pneumococcal infections in adults. PMID:22882668
Streptococcus equi ssp. zooepidemicus (Streptococcus zooepidemicus, SEZ) is responsible for a wide variety of infections in many species. Attempts to control the infection caused by this agent are hampered by a lack of effective vaccines and useful diagnostic kits. Surface proteins of bacterial species are usually involved in interaction with host and hopefully act as biomarkers for serodiagnosis and subunit vaccine components. In this study, the surface proteins of SEZ C55138 strain were systematically identified by surface shaving with trypsin and a total of 20 surface associated proteins were found. Further analysis of five selected novel proteins (SzM, FBP, SAP, CSP and 5'-Nu) revealed that they all expressed in vivo and their recombinant derived proteins could be reactive with convalescent sera. These identified immunogenic surface proteins have potential as SEZ vaccine candidates and diagnostic markers. PMID:22613253
Barboza-Silva E, Castro ACD, Marquis RE. Fluoride, triclosan and organic weak acids as modulators of the arginine deiminase system in biofilms and suspension cells of oral streptococci.Oral Microbiol Immunol 2009: 24: 265-271.Copyright 2009 John Wiley &Sons A/S. Introduction: The arginine deiminase system (ADS) of oral bacteria is a major generator of alkali (ammonia) in dental plaque and is considered to have anticaries effects. However, many of the antimicrobial agents used in oral care products may reduce alkali production by the ADS. The objective of our work was to assess the sensitivity of the ADS of oral streptococci to commonly used antimicrobials, fluoride, triclosan and organic weak acids. Methods: Streptococcus sanguinis NCTC 10904 and Streptococcus ratti FA-1 were grown in susp...
Streptococcus equi ssp. zooepidemicus (Streptococcus zooepidemicus, SEZ) is responsible for a wide variety of infections in many species. Attempts to control the infection caused by this agent are hampered by a lack of effective vaccines and useful diagnostic kits. Surface proteins of bacterial species are usually involved in interaction with host and hopefully act as biomarkers for serodiagnosis and subunit vaccine components. In this study, the surface proteins of SEZ C55138 strain were systematically identified by surface shaving with trypsin and a total of 20 surface associated proteins were found. Further analysis of five selected novel proteins (SzM, FBP, SAP, CSP and 5'-Nu) revealed that they all expressed in vivo and their recombinant derived proteins could be reactive with convale...
Abstract in spanish La mastitis en novillas es un problema que ha alcanzado importantes dimensiones a medida que las explotaciones lecheras se han especializado. Las hembras bovinas son susceptibles a infecciones intramamarias (IIM) desde el momento en que la glándula mamaria se ha desarrollado completamente en el feto. Factores relacionados al animal, al medio en que se desarrolla y al manejo incrementan o reducen el riesgo de contraer IIM. El grupo de bacterias mas usualmente asociadas co (more) n IIM en novillas gestantes son los Staphylococcus coagulasa negativos (SCN), pero otras bacterias como Staphylococus aureus, Mycoplasma spp, Streptococcus uberis y Streptococcus agalactiae, son tambien importantes agentes etiológicos de IIM. Las alternativas al manejo de la mastitis en novillas están dirigidas a la reducción de factores de riesgo y se complementan con la administración de terapias de sellamiento físico del pezón, desinfectantes o antibióticas, previa evaluación de los programas de sanidad de hato con que cuenta cada explotación. Abstract in english Mastitis in dairy heifers is a problem that has reached remarkable importance since the development of highly specialized dairy operations. The bovine female is susceptible to intramammary infections (IMI) from the moment at which the mammary gland is completely developed in the fetus. A number of features, from individual-based variability to environmental and managerial practices can increase or decreased the risk to acquire IMI. The bacteria most commonly associated wi (more) th IMI are coagulase negative Staphylococcus (CNS), however, other pathogens including Staphylococus aureus, Mycoplasma spp, Streptococcus uberis y Streptococcus agalactiae, are also ethiological agents of IMI. Management alternatives for mastitis in dairy heifers are aimed towards the reduction of risk factors, and are complemented by the inclusion of teat sealants, disinfectants, and antibiotics, in addition to a prior evaluation of herd health programs in each dairy farm.
Characteristic differences between saliva-dependent aggregation and adhesion of streptococci.
Comparison of saliva-mediated aggregation of Streptococcus sanguis, Streptococcus mitis, and Streptococcus mutans and adhesion of these organisms to saliva-coated hydroxyapatite showed that there was no relationship between these two activities. Adsorption of salivary aggregating activity to bacteri...
The in vitro activity of ceftobiprole was evaluated against 15 011 clinical isolates obtained from patients in Canadian hospitals between 2007 and 2009. All Staphylococcus aureus were susceptible to ceftobiprole (MIC(90)'s for methicillin-susceptible Staphylococcus aureus and methicillin-resistant Staphylococcus aureus of ? 1 ?g/mL and 2 ?g/mL, respectively). Ceftobiprole was active against penicillin-susceptible Streptococcus pneumoniae (MIC(90), ? 0.06 ?g/mL), penicillin-resistant Streptococcus pneumoniae (MIC(90), 0.5 ?g/mL), Streptococcus pyogenes (MIC(90), ? 0.06 ?g/mL), Staphylococcus epidermidis (MIC(90), ? 1 ?g/mL), and Enterococcus faecalis (MIC(90), ? 1 ?g/mL). Over 90% of Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, Citrobacter freundii, Proteus mirabilis, and Serratia marcescens isolates were inhibited by a ceftobiprole concentration of ? 1 ?g/mL. Ceftobiprole was not active against extended-spectrum ?-lactamase-producing Escherichia coli and K. pneumoniae. The in vitro activity of ceftobiprole versus Pseudomonas aeruginosa was similar to that of cefepime (MIC(90), 16 ?g/mL). The broad spectrum of activity by ceftobiprole would support further study of this agent in the treatment of hospital-acquired infections. PMID:21353964
OBJECTIVE: The aim of this study was to examine the effect of ursolic acid (UA) and oleanolic acid (OA), triterpenoid compounds that are isolated from many edible and medicinal plants, on cariogenic microorganisms and biofilms. METHODS: A microtitre plate dilution assay was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of UA and OA against two Actinomyces spp. and four Streptococcus spp. The antibacterial activity of UA and OA was assessed by crystal violet staining, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). RESULTS: UA and OA displayed differential antibacterial activities against the six tested bacteria, with UA showing greater antibacterial activity than OA. Furthermore, the two drugs had greater antibacterial activity against Actinomyces spp. than Streptococcus spp. UA and OA at 1/4 MIC can reduce bacterial biofilm formation, whereas higher UA concentrations displayed antibacterial activity against Actinomyces viscosus and Streptococcus mutans in mature biofilms. For instance, 2.0 mg ml(-1) UA was sufficient to kill an A. viscosus biofilm. CONCLUSIONS: UA and OA inhibit the growth of cariogenic microorganisms, which suggests that UA and OA have considerable potential as antibacterial agents for dental caries prevention. PMID:23114261
We have developed a novel high-throughput PCR-ligase detection reaction-capillary electrophoresis (PCR-LDR-CE) assay for the multiplexed identification of 20 blood-borne pathogens (Staphylococcus epidermidis, Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis, Enterococcus faecium, Listeria monocytogenes, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Escherichia coli, Klebsiella pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, Acinetobacter baumannii, Neisseria meningitidis, Bacteroides fragilis, Bacillus anthracis, Yersinia pestis, Francisella tularensis, and Brucella abortus), the last four of which are biothreat agents. The method relies on the amplification of two regions within the bacterial 16S rRNA gene, using universal PCR primers and querying the identity of specific single-nucleotide polymorphisms within the amplified regions in a subsequent LDR. The ligation products vary in color and size and are separated by CE. Each organism generates a specific pattern of ligation products, which can be used to distinguish the pathogens using an automated software program we developed for that purpose. The assay has been verified on 315 clinical isolates and demonstrated a detection sensitivity of 98%. Additionally, 484 seeded blood cultures were tested, with a detection sensitivity of 97.7%. The ability to identify geographically variant strains of the organisms was determined by testing 132 isolates obtained from across the United States. In summary, the PCR-LDR-CE assay can successfully identify, in a multiplexed fashion, a panel of 20 blood-borne pathogens with high sensitivity and specificity. PMID:17428930
The aim of this study was to evaluate the in vitro activity of cefditoren and comparators against Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis causing community-acquired respiratory tract infections (CARTIs). A total of 391 Streptococcus pneumoniae, 266 H. influenzae, and 76 M. catarrhalis were isolated from 10 centers located at 6 cities in China from January 2009 to May 2010. The microdilution method was used to determine minimum inhibitory concentrations (MICs). The pneumococci comprised 189 (48.3%) penicillin susceptible, 129 (33.0%) penicillin intermediate, and 73 (18.7%) penicillin resistant. Moxifloxacin and levofloxacin showed the highest activity (99.2% and 97.7%, respectively) against Streptococcus pneumoniae, followed by parenteral penicillin G (95.7%), cefditoren (83.1%) and amoxicillin-clavulanic acid (79.3%). Among the 266 H. influenzae isolates, 26 (9.8%) were ampicillin-resistant ?-lactamase-producing strains and 24 (9.0%) were ampicillin-resistant ?-lactamase-nonproducing strains (BLNAR). Most of antimicrobial agents demonstrated good activity (>97% susceptibility) against H. influenzae except ampicillin, cefuroxime, and cefaclor, which showed relatively lower activity (81.2%, 88.7%, and 88%, respectively). Cefditoren showed excellent activity with the lowest MIC(50) and MIC(90) (?0.016/0.064 ?g/mL) among all tested drugs, which is independent of ?-lactamase production or ampicillin resistance. Cefditoren at a concentration of 0.5 ?g/mL inhibited all BLNAR strains. Seventy of 76 isolates of M. catarrhalis produced ?-lactamase. Cefditoren also showed excellent activity with MIC(90) of 0.064 ?g/mL against ?-lactamase-nonproducing strains and 0.5 ?g/mL against ?-lactamase-producing strains. In conclusion, the excellent intrinsic activity of cefditoren suggests that it may be a good choice for the treatment of CARTIs caused by Streptococcus pneumoniae, H. influenzae, and M. catarrhalis in China, while the activity should be closely monitored. PMID:22521692
Virioplankton: viruses in aquatic ecosystems
Dairy cow mastitis is an important disease in the dairy industry. Different microbial species have been identified as causative agents in mastitis, and are traditionally diagnosed by bacterial culture. The objective of this study was to use metagenomic pyrosequencing of bacterial 16S rRNA genes to investigate bacterial DNA diversity in milk samples of mastitic and healthy dairy cows and compare the results with those obtained by classical bacterial culture. One hundred and thirty-six milk samples were collected from cows showing signs of mastitis and used for microbiological culture. Additionally, 20 milk samples were collected from healthy quarters. Bacterial DNA was isolated from the same milk samples and the 16S rRNA genes were individually amplified and pyrosequenced. Discriminant analysis showed that the groups of samples that were most clearly different from the rest and thus easily discriminated were the normal milk samples from healthy cows and those characterised by culture as Trueperella pyogenes and Streptococcus spp. The mastitis pathogens identified by culture were generally among the most frequent organisms detected by pyrosequencing, and in some cases (Escherichia coli, Klebsiella spp. and Streptococcus uberis mastitis) the single most prevalent microorganism. Trueperella pyogenes sequences were the second most prevalent sequences in mastitis cases diagnosed as Trueperella pyogenes by culture, Streptococcus dysgalactiae sequences were the second most prevalent sequences in mastitis cases diagnosed as Streptococcus dysgalactiae by culture, and Staphyloccocus aureus sequences were the third most prevalent in mastitis cases diagnosed as Staphylococcus aureus by culture. In samples that were aerobic culture negative, pyrosequencing identified DNA of bacteria that are known to cause mastitis, DNA of bacteria that are known pathogens but have so far not been associated with mastitis, and DNA of bacteria that are currently not known to be pathogens. A possible role of anaerobic pathogens in bovine mastitis is also suggested. PMID:10704475
Methods and compositions for diagnosing and preventing a group B streptococcal infection
The present invention provides a group B streptococcal (GBS) surface antigen, designated epsilon antigen, that is co-expressed with the delta antigen on a subset of serotype III GBS. Epsilon is expressed on more pathogenic Restriction Digest Pattern (RDP) III-3 GBS, but not on RDP types 1, 2, or 4. Accordingly, the present invention provides compositions and methods for detecting a group B streptococcus serotype III, RDP III-3 strain. Vaccines and methods of identifying agents which inhibit adhesion of a group B streptococcal cell to a host cell are also provided.
In vitro evaluation of different chemical agents for the decontamination of gutta-percha cones.
This study evaluated the effectiveness of three disinfectants used in Dentistry for decontamination of gutta-percha cones. Sixty gutta-percha cones were contaminated with standardized pure cultures of five species of microorganisms (Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, Candida albicans ATCC CBS-ICB/USP 562, Bacillus subtilis spores ATCC 6633 and Streptococcus mutans ATCC 25175). The cones were treated with 10% polyvinylpyrrolidone-iodine aqueous solution (PVP-I; Groups 1 and 2), 5.25% aqueous sodium hypochlorite (Groups 3 and 4) and paraformaldehyde tablets (Group 5). All chemical agents were efficient for the cold sterilization of gutta-percha cones in short time periods. PMID:12908064
Introduction: Bacterial resistance is increasing on a global basis, making treatment options more limited. The development of new agents to meet this threat is a matter of urgency. Ceftaroline fosamil, a member of an advanced cephalosporin class of antimicrobials, is currently approved by the US Food and Drug Administration for use in for acute bacterial skin and skin structure infection (ABSSSI) and community-acquired bacterial pneumonia. Ceftaroline displays activity against Gram-positive and Gram-negative bacteria, including both methicillin-susceptible and resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae (including penicillin- and ceftriaxone-resistant strains), respiratory pathogens (such as Moraxella catarrhalis and Haemophilus influenzae, including beta-lactamase-pro...
In an attempt to find a new class of antimicrobial agents, a series of fused chromenone derivatives containing pyridine and quinoline moieties were prepared via the reaction of 4-chloro-2-oxo-2H-chromene-3-carbaldehydes with cyclopentanone or cyclohexanone or ?-tetralone in the presence of ammonium acetate in refluxing glacial acetic acid. The target molecules were also synthesized using interchange component strategy. These compounds were screened for their antibacterial activity against Gram-positive bacteria (Staphylococcus aureus and Streptococcus pyogenes), Gram-negative bacteria (Pseudomonas phaseolicola and Pseudomonas fluorescens), and antifungal activity against Fusarium oxysporum and Aspergillus niger. The compounds exhibited good to moderate antibacterial and antifungal propert...
Streptococcus agalactiae is an important agent in the infection of neonates in the first world. One of the most extended methods for its identification is based on the detection of a characteristic red pigment in the patient samples, named [12]-granadaene (1). In this article, we present a modular and flexible approach to simple analogues of this ornithine rhamno-polyene 1 and the elucidation of the most important features of its structure: the absolute configuration at C-27, the stereochemistry of the anomeric center and the link of the amino acid ornithine to the rest of the structure.
Medicinal plants in the healing of dry socket in rats: microbiological and microscopic analysis.
The effectiveness of medicinal herbs as antimicrobial agents was tested on isolated microorganisms from an induced alveolitis and on alveolitis in rats. Sixteen ethanolic extracts from plants were prepared and tested. The plant materials were selected from ethnobotanic data and the best result was obtained with Schinus terebinthifolius Raddi. The activity on Enterococcus, Bacillus corineforme, Streptococcus viridans and S. beta-hemolytic was better than the one presented by the antibiotic currently used for the treatment of alveolitis. The extract of Schinus terebinthifolius Raddi has shown good wound-healing activity by histological analysis. PMID:11995943
Background BC-3781 is an investigational semi-synthetic pleuromutilin antibiotic, which recently finished a clinical Phase 2 trial in acute bacterial skin and skin structure infections. BC-3781 binds to the 50S ribosomal subunit and cross-resistance with other antimicrobial classes is uncommon. We evaluated the activity of BC-3781 against organisms responsible for community-acquired respiratory tract infections (CARTIs). Methods BC-3781 and comparator agents were susceptibility tested against Streptococcus pneumoniae (157 isolates; 33% penicillin resistant), Haemophilus influenzae (102; 50% ?-lactamase producers), Moraxella catarrhalis (50) and Legionella pneumophila (30) by broth microdilution and the agar dilution method. Mycoplasma pneumoniae (50 strains) was tested...
As the increasing prevalence of resistant strains of respiratory bacterial pathogens has recently been reported, continuous monitoring of the susceptibility of clinical isolates to antibacterial agents is important. We performed a surveillance study focusing on the susceptibility of major respiratory bacterial pathogens in the northeastern region of Japan to carbapenems and control drugs. A total of 168 bacterial strains isolated from patients with respiratory tract infections in 2007 were collected and the minimum inhibitory concentration (MIC) determined. MIC data were subjected to pharmacokinetic/pharmacodynamic analysis with Monte Carlo simulation to calculate the probability of achieving the target of time above MIC with each carbapenem. All Moraxella catarrhalis, Streptococcus pneumo...
Potential Oral Health Benefits of Cranberry
In the past decade, cranberry extracts have been attracting ever-growing attention by dental researchers. The potential benefits of cranberry components in reducing oral diseases, including dental caries and periodontitis, are discussed in this review. A non-dialysable cranberry fraction enriched in high molecular weight polyphenols has very promising properties with respect to cariogenic and periodontopathogenic bacteria, as well as to the host inflammatory response and enzymes that degrade the extracellular matrix. Cranberry components are potential anti-caries agents since they inhibit acid production, attachment, and biofilm formation by Streptococcus mutans. Glucan-binding proteins, extracellular enzymes, carbohydrate production, and bacterial hydrophobicity, are all affected by cranb...
High burden of antimicrobial resistance in Asia
Antimicrobial resistance is associated with high mortality rates and high medical costs. Marked variations in the resistance profiles of bacterial and fungal pathogens as well as the quality of public hygiene have had a considerable impact on the effectiveness of antimicrobial agents in Asian countries. In Asia, one of the epicentres of antimicrobial drug resistance, there is an alarming number of antibiotic-resistant species, including penicillin- and erythromycin-resistant Streptococcus pneumoniae, ampicillin-resistant Haemophilus influenzae, multidrug-resistant (MDR) Acinetobacter baumannii, extended-spectrum b-lactamase (ESBL)-producing Klebsiella pneumoniae (particularly mediated by CTX-M-9, CTX-M-14 and CTX-M-15), New Delhi metallo-b-lactamase 1 (NDM-1)-producing Enterobacteriaceae, ...
Bacterial microleakage along the tooth/composite resin dental restoration interface contributes to post-operative sensitivity, recurrent caries, pulp inflammation and necrosis. Studies have confirmed that saliva can catalyze the degradation of constitutive monomers in dental restorative composites, forming biodegradation by-products (BBPs) such as methacrylic acid (MA), and triethylene glycol (TEG). TEG accelerates the growth of Streptococcus mutans, a major etiological agent of dental caries. Restriction fragment differential display polymerase chain reaction (RFDD-PCR) in conjunction with single strand conformation polymorphism (SSCP) was used to identify S. mutans genes with differential expression when grown in the presence of TEG at pH levels 5.5 and 7.0. Quantitative real-time PCR (q...
Introduction Clinical/microbiological studies have consistently revealed the persistence of some bacteria after conventional root canal debridement. Although this was originally attributed to the complexity of the root canal anatomy and the difficulty of delivering antibacterial agents effectively, it has emerged that the biofilm encasement of bacterial cells may confer a further mechanism of resistance. The purpose of this study was to investigate the relative disruption and bactericidal effects of root canal irrigants on single- and dual-species biofilms of root canal isolates. Methods Biofilms of Streptococcus sanguinis, Enterococcus faecalis, Fusobacterium nucleatum, and Porphyromonas gingivalis were grown on nitrocellulose membranes for 72 hours and immersed in NaOCl, EDTA, chlorhexid...
Abstract in portuguese Avaliamos o desempenho da reação em cadeia da polimerase (PCR) para detecção simultânea da Neisseria meningitidis, Haemophilus influenzae e Streptococcus sp. no diagnóstico das meningites bacterianas e sua aplicabilidade na rotina diagnóstica. Foi realizado um estudo de coorte com 182 crianças apresentando suspeita de meningite bacteriana. Em 84, havia alterações clínicas e laboratoriais sugestivas de meningite bacteriana. Destas, 65 tiveram o agente etiológic (more) o identificado pelos métodos laboratoriais de rotina e 19 ficaram sem diagnóstico etiológico. Em 98 pacientes foi excluído o diagnóstico de meningite bacteriana. Analisando o desempenho da PCR encontramos sensibilidade de 88,1%, especificidade de 99,0% e valores preditivos positivo e negativo de 98,7% e 90,1% respectivamente. Nos 19 pacientes com meningite bacteriana mas sem diagnóstico etiológico a PCR detectou microrganismos em 14, sendo 12 N. meningitidis, um H. influenzae e um Streptococcus sp. A PCR possui o potencial de poder aumentar os índices de identificação das técnicas tradicionais, principalmente nas situações onde a microscopia direta, cultura ou identificação antigênica são negativos ou inconclusivos. Abstract in english The simultaneous detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus sp. was assessed by polymerase chain reaction (PCR) for the diagnosis of bacterial meningitis, as well as the applicability of PCR as a routine test. A cohort study was carried out with 182 children (2 months to 12 years of age) with suspicion of bacterial meningitis. Routine tests identified the etiologic agent in 65/84 children whose clinical status and laboratory findings su (more) ggested the presence of bacterial meningitis. Bacterial meningitis was ruled out in 98 children. In 19 children, the etiologic diagnosis was not possible using standard methods; in 14 of these patients, the etiologic agent was identified by PCR (N. meningitidis=12; H. influenzae=1; Streptococcus sp.=1). The sensitivity of PCR was 88.1%; specificity, 99.0%; positive predictive value, 98.7%; and negative predictive, 90.1%. PCR is a useful complementary diagnostic technique, especially when Gram stain, culture, or antigenic detection are negative or inconclusive.
Microbiologia dos abscessos peritonsilares/ Microbiology of peritonsillar abscesses
Abstract in portuguese OBJETIVO: O objetivo deste estudo é avaliar a microbiologia dos abscessos periamigdalianos. MATERIAIS E MÉTODOS: Trinta pacientes com diagnóstico de abscesso periamigdaliano, idade média de 24,2 anos, foram submetidos à punção na região periamigdaliana de maior abaulamento com aspiração do material purulento (volume maior que 3mL). O material foi separado para realização das culturas aeróbicas e anaeróbicas. RESULTADOS: Houve um índice de positividade das c (more) ulturas de 86,7%. Em 23,3% aspirados houve crescimento apenas de bactérias aeróbicas ou facultativas, 3,3% apenas de bactérias anaeróbicas e por fim em 60% aspirados houve crescimento de bactérias aeróbicas e anaeróbicas. Um total de 69 bactérias foi isolado (34 aeróbios e 35 anaeróbios). Os aeróbios predominantes foram Streptococcus sp, sendo o Streptococcus pyogenes em 23% dos casos. Os anaeróbios predominantes foram Prevotella sp e Peptostreptococcus sp. Pacientes receberam antibiótico prévio em 63% dos casos. Neste grupo foram isolados 1,8 bactérias por aspirado, menor número que nos paciente que não utilizaram antibiótico (3,0 bactérias por aspirado). Não houve diferença significativa no tipo de bactéria isolada nestes dois grupos. CONCLUSÃO: Os abscessos periamigdalianos apresentam na maioria dos casos infecções polimicrobianas, sendo os organismos anaeróbicos agentes importantes. O número de agentes isolados é maior nos pacientes que não utilizaram antibioticoterapia prévia, mas o uso de antimicrobiano não interferiu no tipo de bactéria isolada. Abstract in english AIM: The objective of the present study was to analyze the microbiology of peritonsillar abscesses. METHODS: Thirty patients, mean age 24,2 years, with peritonsillar abscesses underwent aspiration of at least 3 mL of pus, which was cultured for aerobes and anaerobes. RESULTS: 87% samples showed positive cultures. Aerobic or facultative aerobic bacteria were isolated from 23% aspirates, mixed aerobic and anaerobic bacteria from 60%, and anaerobic bacteria from only 3% aspi (more) rate. A total of 69 bacterial isolates (34 aerobic and 35 anaerobic) were recovered. The most common aerobic isolate was Streptococcus sp, with Streptococcus pyogenes being identified in 23% of aspirates. The predominant anaerobic isolates were Prevotella sp and Peptostreptococcus sp. Patients had received previous antimicrobial therapy in 63% cases. In this group, 1.8 isolates per specimen were recovered, a lower number than in the untreated group (3.0 per specimen). No significant difference in the species isolated was observed between these two groups. CONCLUSION: Peritonsillar abscess is usually a polymicrobial infection, with predominance of anaerobic bacteria. The number of agents isolated was larger in patients not previously treated with antibiotics, but the use of antimicrobial drugs did not interfere with the type of bacterium isolated.
Abstract in portuguese Objetivo: determinar a prevalência dos agentes etiológicos das meningites bacterianas em serviço de referência, no atendimento de doenças infecciosas para o estado de Minas Gerais, e verificar a resposta ao tratamento utilizado.Métodos: estudo descritivo em que foram incluídas todas as crianças com diagnóstico provável de meningite, admitidas na instituição no período de junho a novembro/99.Resultados: obteve-se 210 casos de meningite, sendo 111 casos de etio (more) logia bacteriana (52,9%). Destes, 52 casos foram diagnósticos prováveis (por alteração do liquor rotina) e 59 com diagnósticos de certeza (por cultura e/ou isolamento de antígeno). Os principais agentes isolados foram, em ordem decrescente, H. influenzae, N. meningitidis e S. pneumoniae. O tratamento inicial para a faixa etária de três meses a cinco anos foi ampicilina e cloranfenicol, sendo posteriormente restrito para penicilina em casos de meningococo e pneumococo, e para cloranfenicol nos casos de H. influenzae. A mudança para antimicrobiano de maior espectro foi realizada com base em dados clínicos ou laboratoriais, não havendo isolamento de microorganismo resistente.Conclusões: o acompanhamento do perfil epidemiológico das meningites deve ser contínuo, e cada serviço deve se basear em dados locais para direcionar a terapia antimicrobiana. A monitorização contínua dos agentes prevalentes em cada instituição e de sua resistência é fundamental para a escolha antimicrobiana, atuando com menor interferência na colonização individual, sem contribuir para a crescente resistência dos agentes responsáveis pelas infecções meníngeas. Abstract in english Objective: to establish the prevalence of the etiological agents of bacterial meningitis in a reference center for the treatment of infectious diseases in the state of Minas Gerais. Methods: descriptive study including all children with probable diagnosis of meningitis between June/1999 and November/1999.Results: there were 210 cases of meningitis, and 111 (52.9%) were caused by bacteria. Actually, 52 were probable bacterial meningitis (with liquor alterations) and 59 wer (more) e confirmed (with culture and/or antigen tests). The main agents were: Haemophilus influenzae, Neisseria meningitidis and Streptococcus pneumoniae. The initial treatment for children aged between three months and five years consisted of ampicillin and chloramphenicol. Later, the antibiotic was changed to penicillin in cases of Neisseria meningitidis and Streptococcus pneumoniae. and to chloramphenicol in cases of Haemophilus influenzae. Extended spectrum antimicrobial agents were used on clinical or laboratory basis, but resistant microorganisms were not found in cultures.Conclusions: the epidemiology of meningitis should be continuous and should consider local data in order to guide antimicrobial therapy. The continuous monitoring of the prevalent agents in each institution and their resistance is fundamental to the selection of antimicrobial drugs, preserving the antimicrobial agents, and causing less interference with individual colonization, without contributing to the increasing resistance of the agents responsible for meningeal infections.
Abstract in portuguese Objetivo: revisar a literatura quanto ao diagnóstico etiológico das pneumonias agudas na faixa etária pediátrica. Fonte dos dados: revisão sistemática das citações do Medline e do Lilacs. Síntese dos dados: a utilização dos novos métodos diagnósticos, particularmente as técnicas imunológicas e a reação em cadeia da polimerase, de uso ainda incipiente no Brasil, tem se mostrado importante para a investigação epidemiológica e para a melhora no diagnósti (more) co específico em termos de sensibilidade, especificidade e rapidez de resultados, com finalidade de orientação terapêutica adequada. A revisão dos estudos epidemiológicos das pneumonias agudas adquiridas na comunidade mostrou que o Streptococcus pneumoniae continua sendo o agente bacteriano mais importante, em todas as faixas etárias, tanto nos países desenvolvidos quanto nos em desenvolvimento. A resistência desse agente à penicilina e às cefalosporinas tem aumentado progressivamente em todos os continentes e tem-se constituído em um fator de preocupação. Os agentes de pneumonias atípicas, Mycoplasma pneumoniae e Chlamydia pneumoniae mostram-se, atualmente, como agentes importantes de pneumonias agudas adquiridas na comunidade, particularmente em crianças acima de 4 a 5 anos de idade, correspondendo, em países desenvolvidos, a cerca de até um terço dos casos. No entanto, ainda não está definida a sua importância epidemiológica nos países em desenvolvimento. O vírus respiratório sincicial é um agente freqüente de PAC, pode determinar quadros mais graves, particularmente nos lactentes e crianças menores, sendo muito importante a sua investigação em crianças hospitalizadas por doença do trato respiratório inferior. A utilização das novas vacinas conjugadas contra Streptococcus pneumoniae e Haemophilus influenzae tipo b tiveram um impacto importante na morbidade e mortalidade das infecções causadas por esse agentes. Conclusões: a monitorização microbiológica e antimicrobiana deve ser um trabalho dinâmico e contínuo, e a procura e o desenvolvimento de novas vacinas, particularmente contra o vírus respiratório sincicial, poderá causar um grande impacto na prevenção das pneumonias agudas na infância. Abstract in english Objective: to search literature related to the etiological diagnosis of acute pneumonia in children. Sources: systematic review of Medline and Lilacs databases. Summary of the findings: the use of new diagnostic methods such as immunological techniques and polymerase chain reaction has proven invaluable for specific diagnosis and epidemiological investigation, showing adequate sensitivity, specificity and promptness of results, with the aim of guiding therapy properly. Re (more) view of epidemiological studies of community acquired pneumonia showed that Streptococcus pneumoniae is still one of the most significant etiologic agents in all age groups, in developing and industrialized countries. Resistance of this agent to penicillin and cephalosporins is increasing in all continents and is worrisome. Atypical agents such as Mycoplasma pneumoniae and Chlamydia pneumoniae are common in community acquired pneumonia, mainly in children older than 4 years, representing one third of the cases in industrial countries. However, their prevalence in developing countries remain to be determined. Respiratory syncytial virus is also a very common etiology of community acquired pneumonia and may cause severe infections, mainly in infants and younger children. The introduction of new conjugated vaccines for Streptococcus pneumoniae and Haemophilus influenzae type b resulted in significant reduction of morbidity and mortality of pneumonia in children. Conclusions: a significant impact on morbidity and mortality of acute pneumonia in children is likely to occur if microbiological and antimicrobial control is continuously and dynamically performed, thus allowing for the development of new vaccines, particularly against the respiratory syncytial virus.
Abstract in spanish La fiebre es uno de los síntomas frecuentes de consulta en Servicios de Urgencia pediátricos. Objetivos: Describir causas del síndrome febril agudo sin foco evidente (SFASF) en niños bajo 36 meses de edad, utilidad de exámenes solicitados y conducta del médico. Pacientes y Métodos: Se analizaron 309 fichas de niños bajo 36 meses, que consultaron en el servicio de urgencia por SFASF. Resultados: 64% fue catalogado de buen aspecto clínico al ingreso. Las causas má (more) s frecuentes fueron infecciones probablemente virales respiratorias 72%, infección urinaria 7,4%, neumonía 2,9%, bacteriemia 1,9% y meningitis bacteriana 1,3%. Streptococcus pneumoniae fue el agente más frecuentemente aislado de sangre. Los exámenes de mayor utilidad fueron sedimento de orina y urocultivo. Un recuento de leucocitos Abstract in english Fever is a frequent symptom of consultation in Pediatric Emergency Department. Objectives: to describe causes of acute fever of unknown origin (FUO) in infants under 36 months of age, the utility of requested tests and pediatrician decisions. Patients and Methods: 309 cards of children under 36 months who consulted at Emergency Department for acute FUO were reviewed. Results: 64 % were classified with well clinical condition. Most frequent causes were: probable viral resp (more) iratory infections (72%), urinary tract infection (7.4%), pneumonia (2.9%), bacteremia (1.9%), and bacterial meningitis (1.3%). Streptococcus pneumoniae was the most frequent agent isolated from blood cultures. Tests of best utility were: urine analysis and urine culture. Leukocytes count
Síndrome de Austrian/ Austrian Syndrome: case report
Abstract in portuguese Neste relato, é descrito o caso de um paciente masculino, 64 anos, sem história de etilismo, que se apresentou com a Tríade de Osler, que consiste no desenvolvimento de endocardite, pneumonia e meningite, por um mesmo agente. A síndrome é denominada síndrome de Austrian, quando a infecção for por Streptococcus pneumoniae. Serão discutidas as manifestações clínicas, fisiopatológicas e a terapêutica mais adequada para esse quadro. Tendo em vista a raridade do (more) caso e a elevada morbimortalidade, serão enfatizadas a importância do diagnóstico precoce e o tratamento adequado, visando reduzir as complicações inerentes a essa doença. Abstract in english In this report, we describe the case of a 64-year-old male patient, with no history of alcohol consumption, who presented the Osler's triad, which is the association of endocarditis, pneumonia, and meningitis caused by a single agent. This syndrome is called Austrian syndrome, when the infection is caused by Streptococcus pneumoniae. We discuss the clinical manifestations, the pathophysiology, and the therapeutic approach to this condition. Given the rarity of the conditi (more) on and its high morbidity and mortality, the importance of an early diagnosis and an appropriate treatment to reduce the complications associated with this disease will be emphasized.
Guidelines for management of nonalcoholic fatty liver disease: an updated and revised edition
Objective This study aimed to identify the bacteriological agents of otitis media in Jordanian children and to assess the in vitro susceptibility of these isolates to commonly used antibiotics. Methods Retrospective analysis of consecutive samples submitted for microbiological evaluation from outpatients children aged between 6 months and 15 years who were clinically diagnosed with otitis media and were treated at Princess Rahma Hospital in North Jordan between January 2005 and December 2009. Results A total of 724 isolates were recovered from cultures obtained from 863 children patients giving an isolation rate of 83.8%. The male and female isolate ratio was (1.26:1.0). The most common bacterial species isolated were S. aureus (59.9%) followed by Streptococcus pneumoniae (22.4%), Pseudomonas (7.7%), E. coli (5.9%), Klebsiella spp. (3.1%) and Proteus spp. (0.9%). The most of S. aureus isolates were susceptible to vancomycin (94.0%) and gentamicin (87.3%). Streptococcus organisms were susceptible in highest percentage to amoxicillin-clavulanic acid (87.1%). Gram-negative isolates were highly susceptible to ciprofloxacin (83.5%) and gentamicin (79.8%). Among all isolates, vancomycin was the most effective antimicrobial agent with susceptibility rate of 83.9%, whereas cefixime showed the lowest susceptibility rate of 39.7%. Conclusions S. aureus isolates were the most frequent bacteria isolated from otitis media and were highly sensitive to vancomycin and gentamicin, while gram-negative isolates were more sensitive to ciprofloxacin and gentamicin. PMID:20698076
Meningitis bacteriana: estudio georreferencial en Ciudad de La Habana durante 1998
Abstract in spanish Se analizó el comportamiento de la meningitis bacteriana con agente identificado correspondiente al año 1998 en la provincia Ciudad de La Habana. La aplicación del Sistema de Información Geográfica Mapinfo versión 4.1 permitió conocer la distribución espacial de los enfermos. Se obtuvo como resultado una zona de circulación de Neisseria meningitidis al centro nordeste, una franja al norte y noroeste de la ciudad como área de prevalencia de Streptococcus pneumoni (more) ae y zonas aisladas al centro, sur y este como áreas de prevalencia de Haemophilus influenzae, relacionadas con las principales fuentes de contaminación atmosférica en la provincia. Se evidenció la importancia del análisis espacial en la profundización del conocimiento para el estudio epidemiológico. Abstract in english The behaviour of bacterial meningitis with identified agent in the City of Havana in 1998. The implementation of Geographic Information System Mapinfo 4.1 made it possible to know the spatial distribution of the sick people. As a result, we found an area of circulation of Neisseria meningitidis located to the northeast center; an area of prevalence of Streptococcus pneumoniae to the north and northeast of the city and zones located to the center, east and south where Haem (more) ophlus influenzae prevailed. These areas were related to the main sources of environmental pollution in the province. THe importance of the spatial analysis for expanding the knowledge for an epidemiological study was evidenced.
Responses of fish chromatophore-based cytosensor to a broad range of biological agents.
A cytosensor based on living chromatophores from Betta splendens Siamese fighting fish was used to test several classes of biologically active agents. Tested agents include neurotransmitters, adenyl cyclase activators, cytoskeleton effectors, cell membrane effectors and protein synthesis inhibitors. Characteristic cell responses were analyzed, and potential cytosensor applications were considered. Streptococcus pyogenes toxins streptolysin S and streptolysin O, Clostridium tetani tetanolysin, Staphylococcus aureus alpha-toxin and Vibrio parahemolyticus hemolysin, all bacterial toxins that act on cell membranes, elicited a strong response from chromatophores. A comparison of purified toxin to actual bacterial culture from Vibrio parahemolyticus demonstrated a nearly identical chromatophore cell response pattern. This suggests that the cytosensor response is reflective of bacterial toxin production. PMID:15478182
Fetal calf serum (FCS)-independent pancreatic cancer cells were established in plasma protein fraction (PPF)-supplemented medium that is an agent of good manufacturing practice (GMP) grade. Dendritic cells (DCs) were activated with the Toll-like receptor agonist, penicillin-inactivated Streptococcus pyogenes (OK-432) that is also a GMP grade agent. Therefore, sufficient amounts of FCS-independent fusions were successfully generated with decreased potential hazards of FCS. The FCS-independent fusions expressed tumor-associated antigens, HLA-DR, costimulatory molecules, IL-12, and IL-10. Stimulation of T cells with fusions from healthy donors resulted in proliferation of T cells with high expression levels of perforin/granzyme B and IFN-g and efficient induction of antigen-specific cytotoxic...
Background Because previous studies have indicated that otitis media may be a polymicrobial disease, we prospectively analyzed middle ear effusions of children undergoing tympanostomy tube placement with multiplex polymerase chain reaction for four otopathogens. Methods Middle ear effusions from 207 children undergoing routine tympanostomy tube placement were collected and were classified by the surgeon as acute otitis media (AOM) for purulent effusions and as otitis media with effusion (OME) for non-purulent effusions. DNA was isolated from these samples and analyzed with multiplex polymerase chain reaction for Haemophilus influenzae, Streptococcus pneumoniae, Alloiococcus otitidis, and Moraxella catarrhalis. Results 119 (57%) of 207 patients were PCR positive for at least one of these four organisms. 36 (30%) of the positive samples indicated the presence of more than one bacterial species. Patient samples were further separated into 2 groups based on clinical presentation at the time of surgery. Samples were categorized as acute otitis media (AOM) if pus was observed behind the tympanic membrane. If no pus was present, samples were categorized as otitis media with effusion (OME). Bacteria were identified in most of the children with AOM (87%) and half the children with OME (51%, p?Moraxella catarrhalis were more frequently identified in middle ear effusions than Streptococcus pneumoniae. Conclusions Haemophilus influenzae, Streptococcus pneumoniae, Alloiococcus otitidis, and Moraxella catarrhalis were identified in the middle ear effusions of some patients with otitis media. Overall, we found AOM is predominantly a single organism infection and most commonly from Haemophilus influenzae. In contrast, OME infections had a more equal distribution of single organisms, polymicrobial entities, and non-bacterial agents. PMID:16139472
Streptococcus pneumoniae and Haemophilus influenzae are the major etiologic agents of acute otitis media. This study was aimed to compare the detection rate of S.pneumoniae and H.influenzae by culture and real-time polymerase chain reaction (Rt-PCR) in the middle ear effusions of patients diagnosed as acute otitis media. A total of 60 middle ear effusion samples collected from children with acute otitis media were included in the study. The samples were inoculated and incubated in BACTEC Ped Plus blood culture bottles and BACTEC 9120 system (BD Diagnostic Systems, MD), respectively, and the isolates were identified by conventional methods. For the molecular diagnosis of H.influenzae and S.pneumoniae, ply pneumolysin gene and HIB capsule region, respectively were amplified by Rt-PCR (LightCycler, Roche Diagnostics, Germany). H.influenzae and S.pneumoniae were isolated from 5 (8.3%) and 3 (5%) of the patient samples with conventional culture methods, respectively. In addition in 11.6% of the samples other microorganisms (Staphylococcus epidermidis, Streptococcus intermedius, Streptococcus sanguinis, Moraxella catarrhalis, Pseudomonas aeruginosa, Candida albicans) were also isolated. On the other hand H.influenzae and S.pneumoniae were detected in 38 (63.3%) and 24 (40%) of the samples with Rt-PCR, respectively. There was about eight fold increase in the detection frequency of H.influenzae and S.pneumoniae with Rt-PCR compared to culture methods. When culture was accepted as the gold standard method, the sensitivity, specificity and positive predictive value of Rt-PCR in the detection of H.influenzae and S.pneumoniae were estimated as 80%, 51% and 98.2%, respectively. As a result, Rt-PCR was shown to be a sensitive method and could be preferred for the rapid diagnosis of H.influenzae and S.pneumoniae in the etiological diagnosis of acute otitis media, especially in culture negative cases. PMID:23188581
Prevalence of ?-hemolytic Streptococcus in children with special health care needs.
Pharyngotonsillitis by ?-hemolytic Streptococcus mostly affects children and imunocompromissed, being Streptococcuspyogenes (Group A) the most common agent in bacterial pharyngotonsillitis. AIM:This work targeted the research of ?-hemolytic Streptococcus Group-A (SBHGA) and No-A (SBHGNA) in the oropharynx of individuals with special health needs from the APAE (Maceió-AL). METHOD: A prospective study with oropharynx samples from patients with Down syndrome and other mental disorders (test) and students from a private school (control) aged 5-15 years. Cultures in blood agar (5%) were identified through Gram/catalase tests and bacitracin/trimethoprim-sulfamethoxazole disk diffusion method, applying the chi-squared statistical analysis. RESULTS: A total of 222 bacterial colonies were isolated in 74 individuals from APAE and 65 in the control group. In the test group, previous episodes of pharyngotonsillitis were reported by 36.49% (27/74) and 9.46% (7/74) were diagnosed with symptoms and/or signs suggestive of oropharynx infection. No positive sample of S. pyogenes was confirmed at APAE, being all samples classified as SBHGNA, with 5 SBHGA in the control group. CONCLUSION: The early identification of ?-hemolytic Steptococcus is important for the fast treatment of pharyngotonsillitis and the absence of S. pyogenes avoid future suppurative or not-suppurative sequels in the group from APAE. PMID:23108829
Evaluation of alternative methods for the disinfection of toothbrushes
Abstract in english The aim of this study was to evaluate alternative methods for the disinfection of toothbrushes considering that most of the previously proposed methods are expensive and cannot be easily implemented. Two-hundred toothbrushes with standardized dimensions and bristles were included in the study. The toothbrushes were divided into 20 experimental groups (n = 10), according to microorganism considered and chemical agent used. The toothbrushes were contaminated in vitro by sta (more) ndardized suspensions of Streptococcus mutans, Streptococcus pyogenes, Staphylococcus aureus or Candida albicans. The following disinfectants were tested: 0.12% chlorhexidine digluconate, 50% white vinegar, a triclosan-containing dentifrice solution, and a perborate-based tablet solution. The disinfection method was immersion in the disinfectant for 10 min. After the disinfection procedure, the number of remaining microbial cells was evaluated. The values of cfu/toothbrush of each group of microorganism after disinfection were compared by Kruskal-Wallis ANOVA and Dunn's test for multiple comparisons (5%). The chlorhexidine digluconate solution was the most effective disinfectant. The triclosan-based dentifrice solution promoted a significant reduction of all microorganisms' counts in relation to the control group. As to the disinfection with 50% vinegar, a significant reduction was observed for all the microorganisms, except for C. albicans. The sodium perborate solution was the less effective against the tested microorganisms. Solutions based on triclosan-containing dentifrice may be considered effective, nontoxic, cost-effective, and an easily applicable alternative for the disinfection of toothbrushes. The vinegar solution reduced the presence of S. aureus, S. mutans and S. pyogenes on toothbrushes.
Loop-mediated isothermal amplification (LAMP) constitutes a potentially valuable diagnostic tool for rapid diagnosis of contagious diseases. In this study, we developed a novel LAMP method (seM-LAMP) to detect the seM gene of Streptococcus equi subsp. equi (S. equi), the causative agent of strangles in equids. The seM-LAMP successfully amplified the target sequence of the seM gene at 63°C within 60 min. The sensitivity of the seM-LAMP was slightly lower than the 2nd reaction of the seM semi-nested PCR. To evaluate the species specificity of the seM-LAMP, we tested 100 S. equi and 189 non-S. equi strains. Significant amplification of the DNA originating from S. equi was observed within 60 min incubation, but no amplification of non-S. equi DNA occurred. The results were identical to those of seM semi-nested PCR. To investigate the clinical usefulness of the methods, the seM-LAMP and the seM semi-nested PCR were used to screen 590 nasal swabs obtained during an outbreak of strangles. Both methods showed that 79 and 511 swabs were S. equi positive and negative, respectively, and the results were identical to those of the culture examination. These results indicate that the seM-LAMP is potentially useful for the reliable routine diagnosis of Streptococcus equi subsp. equi infections.
RP 59,500 (Quinupristin-Dalfopristin) is the first semisynthetic injectable streptogramin antimicrobial agent, which is a combination of quinupristin and dalfopristin in a 30:70 ratio. The components of RP 59,500 act synergically to provide bactericidal activity through action at different sites on bacterial ribosomes. In the present study, the antimicrobial activity of RP 59,500 was compared with those of four macrolides (erythromycin, clarithromycin, azithromycin, roxithromycin). Susceptibility testing was carried out by microdilution method on 303 strains of 10 species, especially antibiotic-resistant Gram-positive cocci. RP 59,500 was active against a wide range of Gram-positive cocci including methicillin-resistant Staphylococci and penicillin-resistant Streptococcus pneumoniae. The MICs90 of RP 59,500 against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis were both 0.25 microgram/ml, although those of four macrolides were higher than 32 micrograms/ml. The MICs90 of RP 59,500 against penicillin-sensitive, -intermediate and -resistant S. pneumoniae were all 0.5 microgram/ml, although those of four macrolides against penicillin-resistant S. pneumoniae were higher than 32 micrograms/ml. RP 59,500 also exhibited equivalent activities to the four macrolides against strains of Streptococcus pyogenes. Streptococcus agalactiae and Moraxella catarrhalis. RP 59,500 exhibited the highest activities against Enterococcus faecalis, Enterococcus faecium and Enterococcus avium strains which are intrinsically resistant to most antimicrobial agents. No cross-resistance was observed between RP 59,500 and the four macrolides, which will merit attention in future clinical trials of the agent. The effect of human serum on the MIC of RP 59,500 was studied with strains of S. aureus, S. epidermidis and E. faecalis. The presence of 20% (V/V) serum had little or no effect on the MIC, although 50% (V/V) serum increased MICs by 4-8 folds. Laboratory-induced resistance to RP 59,500 occurred in a stepwise fashion in broth cultures of S. aureus, S. epidermidis and E. facalis strains and the induction rate was slow and no more than four fold increases were observed. Population analysis was performed on RP 59,500 and the reference macrolides against S. aureus ATCC 25,923 strain. Although low frequencies (less than 0.01%) of resistant sub-population were detected with EM, CAM, AZM and RXM, no RP 59,500-resistant sub-population was detected in this study. PMID:9412874
Abstract in portuguese CONTEXTO: Em São Paulo, pneumonia é a principal causa infecciosa de morte infantil. Derrame pleural parapneumônico é uma complicação grave da doença e intervenção cirúrgica pode ser necessária quando o paciente não responde à antibioticoterapia. OBJETIVO: Determinar a etiologia dos derrames pleurais parapneumônicos complicados que necessitaram de intervenção cirúrgica. TIPO DE ESTUDO: Retrospectivo. LOCAL: Hospital Universitário da Universidade de São P (more) aulo. MÉTODOS: A análise de 4.000 prontuários de crianças hospitalizadas por pneumonia de novembro de 1986 a novembro de 1996 mostrou que 115 crianças apresentaram um total de 117 casos de empiema que necessitaram de intervenção cirúrgica. Os autores analisaram os dados clínicos das crianças, correlacionando os achados radiológicos, o estado nutricional e a situação vacinal das crianças. Terapias antimicrobianas prévias e bacterioscopia do derrame pleural também foram analisadas. RESULTADOS: Streptococcus pneumoniae foi o agente mais encontrado, tanto nas hemoculturas quanto nos derrames pleurais. DISCUSSÃO: A cobertura vacinal, o peso ao nascimento e o estado nutricional das crianças estudadas foram analisados e comparados aos dados encontrados em outras publicações. Observamos que derrames pleurais causam desconforto importante e, na maioria dos casos, não se trata de complicação do primeiro episódio infeccioso do aparelho respiratório. O uso prévio de antibióticos alterou o resultado das culturas. O achado de Streptococcus pneumoniae como o agente mais freqüentemente encontrado está de acordo com os resultados de outros autores. No entanto, os antibióticos utilizados após a realização do procedimento são os mesmos utilizados em pneumonias não-complicadas, fato que nos levou a concluir que a pior evolução desses casos não se deve à resistência dos agentes aos antimicrobianos. CONCLUSÃO: O perfil bacteriano na nossa série de casos é semelhante ao descrito para pneumonias não complicadas. Novos estudos serão necessários para se determinar o motivo da pior evolução dessas crianças. Abstract in english CONTEXT: In São Paulo, pneumonia is the main infectious cause of death among children. Parapneumonic pleural effusion is a possible complication and has to be treated surgically when the patient does not respond to antibiotics. OBJECTIVE: Assessment of the etiology of complicated parapneumonic pleural effusions that needed surgical intervention. TYPE OF STUDY: Retrospective study. SETTING: University hospital of the University of São Paulo. METHOD: Analysis of 4,000 fil (more) es on children hospitalized with pneumonia from November 1986 to November 1996 had shown that 115 of these children presented a total of 117 cases of pleural empyema that required surgical procedures. The children's clinical condition was assessed in relation to radiological findings and to their nutrition and immunization status. Previous antimicrobial therapy and pleural effusion bacterioscopy were also evaluated. RESULTS: Streptococcus pneumoniae was the agent found most commonly, as frequently in blood cultures as in pleural effusions. DISCUSSION: Data on vaccination coverage, birth weight and nutritional status are analyzed and compared to other publications. We observed that pleural effusion has a high potential for discomfort, and in most cases it is not a complication of the first pulmonary disease episode. Previous use of antibiotics interfered with culture positivity. The agent most frequently found was Streptococcus pneumoniae, which is in accordance with the findings from other authors. Nonetheless, the antibiotics used to treat the patients after the procedure were the same used in non-complicated pneumonias, which has led us to conclude that the worse outcome in this cases was not due to drug resistance. CONCLUSION: The bacteriological profile in our series of complicated pneumonia cases was similar to what has been described for non-complicated pneumonia cases. Future studies will be necessary to determine why these children presented a worse outcome.
Abstract in spanish La otitis media aguda (OMA) es un diagnóstico frecuente en pediatría. Streptococcus pneumoniae continúa siendo el germen más prevalente a nivel mundial, seguido de Haemophilus influenzae. Sin embargo, la introducción de vacunas contra el neumococo ha venido cambiando la microbiología de la OMA. Objetivo. Establecer la prevalencia del neumococo, sus serotipos y la prevalencia de otros gérmenes comunes en niños latinoamericanos con OMA. Fuente de los datos. Se reali (more) zó una búsqueda sistemática de artículos originales en siete bases de datos, limitada a publicaciones entre 1999 y 2010, a menores de 18 años y a idiomas inglés y castellano. Se completó la búsqueda por estrategia de "bola de nieve". Métodos de revisión. Los criterios de elegibilidad incluyeron artículos originales de prevalencia de corte transversal, realizados en población pediátrica latinoamericana y con criterios de inclusión y exclusión homogéneos. Se extrajo la información pertinente de los artículos seleccionados. Resultados. Once artículos cumplieron los criterios de elegibilidad. En Latinoamérica, específcamente en Costa Rica, Chile, Brasil y Argentina, el germen más prevalente fue Streptococcus pneumoniae (43,5%), (el serotipo más frecuente es el 19F, excepto en Argentina, donde es el 14) seguido por Haemophilus influenzae (30%) y Moraxella catarrhalis (6,4%). Conclusiones. El germen más prevalente en OMA en niños latinoamericanos es Streptococcus pneumoniae, hallazgo concordante con lo registrado en Europa y Estados Unidos. Se requieren más estudios en los otros países de la región y su población pediátrica vacunada contra el neumococo, con el fin de establecer un perfil epidemiológico y microbiológico actualizado de Latinoamérica. Abstract in english Acute otitis media (AOM) is a common diagnosis in children. Streptococcus pneumoniae remains the most prevalent agent worldwide, followed by Haemophilus influenzae. However, the introduction of pneumococcal vaccines has changed the microbiology of AOM. Objective. To establish the prevalence of pneumococcal serotypes and other common germs in Latin American children with AOM. Source of data. We carried out a systematic search for original articles in seven databases, limit (more) ed to publications between 1999 and 2010, children under 18, and English and Spanish languages. Search was completed with "snowball" strategy. Review methods. Eligibility criteria included original prevalence cross-sectional articles, conducted in pediatric populations in Latin America, with homogeneous inclusion and exclusion criteria. Relevant information was extracted from the selected articles. Results. Eleven articles met the eligibility criteria. In Latin America, specifically Costa Rica, Chile, Brazil and Argentina, Streptococcus pneumoniae (43.5%) was the most frequent germ, (serotype 19F is the most frequent, except in Argentina where it is 14) followed by Haemophilus influenzae (30%) and Moraxella catarrhalis (6.4%). Conclusions. The more prevalent germ in Latin American children AOM is Streptococcus pneumoniae, a finding consistent with those from Europe and the U.S. Further studies are required in the other countries of the region and its pediatric pneumococcal vaccinated population, in order to establish an updated epidemiological and microbiological profile in Latin America.
Infectious arthritis in patients with rheumatoid arthritis.
Eleven cases of infectious arthritis occurring in patients with rheumatoid arthritis are reported. Staphylococcus aureus was the causative organism in eight patients. Streptococcus anginosus and Streptococcus agalactiae in one patient each, and Mycobacterium tuberculosis in two patients. The mean du...
Mass transport of macromolecules within an in vitro model of supragingival plaque.
The aim of this study was to examine the diffusion of macromolecules through an in vitro biofilm model of supragingival plaque. Polyspecies biofilms containing Actinomyces naeslundii, Fusobacterium nucleatum, Streptococcus oralis, Streptococcus sobrinus, Veillonella dispar, and Candida albicans were...
Comparative analysis of gene expression among low G+C gram-positive genomes
We present a comparative analysis of predicted highly expressed (PHX) genes in the low G+C Gram-positive genomes of Bacillus subtilis, Bacillus halodurans, Listeria monocytogenes, Listeria innocua, Lactococcus lactis, Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus, Clostridi...
Streptococcus agalactiae, Lancefield group B Streptococcus (GBS), is recognized for causing cattle mastitis, human neonatal meningitis, and fish meningo-encephalitis. We investigated the genomic diversity of GBS isolates from different phylogenetic hosts and geographical regions using serological t...
Gaudy, Elizabeth T. (University of Illinois, Urbana), and R. S. Wolfe. Ureidoglycolate synthetase of Streptococcus allantoicus. II. Properties of the enzyme and reaction equilibrium. J. Bacteriol. 90:1531–1536. 1965.—The properties of ureidoglycolate synthetase from Streptococcus allantoicus grown o...
Quinolone resistance is an emerging problem in Streptococcus pyogenes, and recombination with Streptococcus dysgalactiae DNA has been implicated as a frequent mechanism leading to resistance. We have characterized a collection of S. dysgalactiae subsp. equisimilis isolates responsible for infections...
In Vitro Evaluation of Seven Cationic Detergents as Antiplaque Agents
The bactericidal efficacy of seven cationic detergents was studied in vitro against intact performed plaques of representative strains of four oral dental plaque-forming microorganisms: Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, and Actinomyces naeslundii. Both absolute (plaq...
Objective: Group B streptococcus (GBS, Streptococcus agalactiae) is an important cause of neonatal sepsis. Prevention is possible by intrapartum screening for maternal GBS carriership and antimicrobial treatment of colonized women with risk factors during labor. The conflicting results of diagnostic...
Transformation and fusion of Streptococcus faecalis protoplasts.
Nonconjugative plasmids were transferred by protoplast fusion among Streptococcus faecalis strains and from Streptococcus sanguis to S. faecalis. S. faecalis protoplasts were also transformed with several different plasmids, including the Tn917 delivery vehicle pTV1. Transformation was reproducible,...
The effectiveness of a teat dip with dodecyl benzene sulfonic acid (1.94%) for the prevention of intramammary infections was determined in cows experimentally challenged with Streptococcus agalactiae and Staphylococcus aureus. The infection rates with Streptococcus agalactiae and Staphylococcus aure...
Prevención de las infecciones respiratorias agudas: Presente y futuro
Abstract in spanish Las infecciones respiratorias agudas (IRA), son las causas más frecuentes de morbilidad en el mundo y de elevada mortalidad particularmente en los países en desarrollo. Los virus son los agentes etiológicos más frecuentes. Los virus influenza a y b, y el virus sincitial respiratorio (VSR) son los más importantes por la severidad de la enfermedad y por la alta transmisibilidad. Las bacterias, principalmente el Streptococcus pneumoniae (neumococo), y el Haemophilus inf (more) luenzae tipo B (Hib), son las causas más frecuentes de neumonías adquiridas en la comunidad. Las estrategias generales en la prevención y en el tratamiento se basan en: evaluar sistemáticamente los conocimientos existentes acerca de las IRA, divulgarlos y aplicarlos, desarrollar una guía nacional para las indicaciones de los antibióticos, aplicar las vacunas existentes: DPT, triple viral (SRP), anti-Hi, incrementar la inmunización contra el neumococo y los virus influenza, particularmente en grupos de riesgo y desarrollar y evaluar nuevas vacunas contra el VSR, Haemophilus influenzae no serotipificables, Bordetella pertussis y otros agentes infecciosos que afectan el aparato respiratorio. Se realiza una revisión de nuevos agentes y drogas antivirales, así como del desarrollo presente y futuro de las inmunizaciones contra los principales virus y bacterias, que causan infecciones respiratorias agudas. Abstract in english Acute respiratory infections (ARI) are the most frequent cause of morbidity and of the high mortality in the world, particularly in the developing countries. The viruses are the most common etiological agents.The influenza a and b viruses and the syncytial respiratory virus (SRV) are the most important due to the severity of the disease and to their high transmissibility. The bacteria, mainly Streptococcus pneumoniae (Pneumococcus), and Haemophilus influenzae type B (Hib) (more) , are the most frequent cause of pneumonias acquired in the community. The general strategies in the prevention and treatment are based on systematically developing the existing knowledge about ARI, spreading and applying it, developing a national guide for the indication of antibiotics, using the existing vaccines, that is, DPT, triple viral (SRP), anti-Hi, increasing the immunization against Pneumococcus and the influenza viruses, specially in risk groups, and developing and evaluating new vaccines against SRV, non-serotypeable Haemophilus influenzae, Bortedella pertussis and other infectious agents affecting the respiratory tract. It is made a review of the new antiviral agents and drugs, as well as of the present and future development of immunizations against the main viruses and bacteria causing acute respiratory infections.
Abstract in spanish INTRODUCCIÓN. El objetivo de la presente investigación fue describir las características clínicas y epidemiológicas de la infección por Estreptococo del grupo A en los recién nacidos egresados de hospitales maternos. MÉTODOS. Se realizó un estudio descriptivo, que incluyó a recién nacidos consecutivos, quienes tuvieron infecciones por estreptococos del grupo A y que estuvieron ingresados en el servicio de neonatología del Hospital Pediátrico Universitario «J (more) uan M. Márquez» entre 1992 y el 2005. Se procesaron y analizaron distintas variables clínicas y epidemiológicas con cálculo de tasas de incidencia y letalidad. RESULTADOS. Se registraron 20 recién nacidos con infección por estreptococos del grupo A, lo cual representó una tasa promedio anual de 0,2 cada 100 ingresos. Esta infección muestra una incidencia con tendencia significativa a disminuir en los últimos años. Según la clasificación utilizada, todas las infecciones fueron de inicio tardío y, de acuerdo al origen, predominaron las adquiridas en la comunidad (95,0 %). La infección de tejidos blandos fue la forma clínica más frecuente (10 de 20; 50 %) y cursó con bacteriemia. Los aislamientos de estreptococos del grupo A tuvieron un 100 % de sensibilidad ante los betalactámicos. Hubo un solo paciente fallecido, afecto de meningitis, lo cual significó una tasa de letalidad del 5,0 %. CONCLUSIONES. El estreptococo del grupo A es un agente causal de infecciones que afectan al recién nacido, fundamentalmente en el ambiente comunitario. Estas infecciones pueden ser letales en algunos pacientes con infección del sistema nervioso central, a pesar del patrón de elevada susceptibilidad a los betalactámicos. Abstract in english INTRODUCTION. The objective of the present investigation was to describe the clinical and epidemiological characteristics of the infection caused by group A Streptococcus in the newborn infants discharged from maternal hospitals. METHODS. A descriptive study that included consecutive newborn infants who had infections caused by group A Streptococcus and that were admitted in the neonatology service of "Juan M. Márquez" Pediatric Teaching Hospital between 1992 and 2005 wa (more) s carried out. Different clinical and epidemiological variables were processed and analyzed by calculating the incidence and lethality rates. RESULTS. 20 newborn infants with infection caused by group A Streptococcus were registered, accounting for an annual average rate of 0.2 per 100 admissions. This infection shows an incidence with a significant trend to decrease in the last years. According to the classification used, all the infections had a late onset, and regarding their origin those acquired in the community prevailed (95.0 %). The infection of the soft tissues was the most common clinical form (10 of 20; 50 %) and evolved with bacteremia. The isolations of group A Streptococcus has 100 % of sensitivity to betalactamics. Only one patient affected with meningitis died, which represented a lethality rate of 5.0 %. CONCLUSIONS. The group A Streptococcus is an agent causing infections that affect the newborn infant, mainly in the community environment. These infections may be lethal in some patients with infection of the central nervous system, in spite of the pattern of elevated susceptibility to betalactamics.
Enolases from fluoride-sensitive and fluoride-resistant streptococci.
The enolase from a highly fluoride-sensitive strain of Streptococcus salivarius and its fluoride-resistant mutant, as well as those from strains of Streptococcus sanguis and Streptococcus mutans with intermediate and low sensitivities to fluoride have been shown to be inhibited by fluoride. Comparis...
With reference to the first Principle of the International Code of Nomenclature of Bacteria, which emphasizes stability of names, it is proposed that the original names Streptococcus sanguis, Streptococcus rattus, Streptococcus cricetus, Erwinia ananas, Eubacterium tarantellus, Lactobacillus sake, Nitrosococcus oceanus, Pseudomonas betle, Rickettsia canada and Streptomyces rangoon, all included in the Approved Lists of Bacterial Names, be conserved. Request for an Opinion
In the present work the M42-A disk diffusion protocols of the Clinical Laboratory Standards Institute were used by two laboratories to provide data on the epidemiological cut-off values for the Streptococcus phocae isolates obtained from diseased Atlantic salmon (Salmo salar) (n=27) and seal (Phoca vitulina) (n=4) to florfenicol (FLO30), erythromycin (ERY15) and oxytetracycline (OTC30). The data generated by the two laboratories for FLO30 zone sizes were normally distributed with a mean of 27.1mm and a standard deviation of 2.5mm, while for ERY15 they had a mean of 25.5mm and a standard deviation of 1.7mm. For FLO30 and ERY15 the wild type cut-off values (COwt) calculated from the data for all 31 strains were 20mm for both agents. Neither of the OTC30 data sets from Lab 1 or Lab 2 was norm...
Severity of varicella infection in 54 patients with diabetes mellitus seen in Arar Central Hospital, Saudi Arabia, between January 1992 and December 1994 was compared with that in 55 apparently healthy controls, seen during the same period. Persistent fever, defined as fever lasting more than five days; extensive skin eruption, defined as affecting more than 50% of the body surface; and secondary bacterial skin infection evidenced by a positive skin culture of Staphylococcus aureus or Streptococcus pyogenes occurred significantly more in diabetics than in healthy controls. The mean duration of the illness in diabetics was 16.8 +/- 3.24 days as compared to 13.6 +/- 3.32 days in healthy controls. These findings suggest that varicella runs a more aggressive course in diabetic patients compared to otherwise healthy individuals. Treatment with the anti-viral agent, acyclovir may be indicated in diabetics with varicella infection. PMID:8904068
Over the last twenty years there has been an alarming increase in isolation of Streptococcus pneumoniae strains with a reduced susceptibility not only to penicillin, but also to other betalactams and macrolides. This phenomenon justifies the great interest in new antibiotics. Cefditoren, a new aminothiazolyl oral cephalosporin, recently commercialized in Italy, is characterized by an extended activity against penicillin-resistant S. pneumoniae. The aim of this study is to evaluate the incidence of the resistance/susceptibility to various antibiotics in 1000 strains of S. pneumoniae (678 SPSS, 219 SPPI and 103 SPPR), clinically isolated during 2009. The data obtained by our in vitro study show that cefditoren is the most active agent against S. pneumoniae. In fact, the MIC90 values of 0.5 micrograms/ml obtained could be particularly significant in therms of therapeutic predictivity. PMID:20943054
A collection of Streptococcus zooepidemicus strains from human and animal infections was examined for DNA banding patterns after nuclease digestion and agarose gel electrophoresis. The large variety of DNA fingerprints found revealed the complexity of the species but showed that isolates from clusters of outbreaks had identical prints. The results confirmed the specificity of bacteriocin and bacteriophage typing of S. zooepidemicus; the technique also gave useful profiles on untypable strains. Strains with common bacteriocin and biotyping patterns from sporadic infections could be differentiated by their DNA fingerprints. In several outbreaks and incidents, more than one strain of S. zooepidemicus were encountered, and the importance of carefully interpreting typing data is stressed. Chromosomal DNA fingerprinting is a very efficient technique for demonstrating differences between strains of S. zooepidemicus, and its use is recommended for future epidemiological studies of this infectious agent. PMID:3572034
Microorganisms from 45 jungle crows (Corvus macrorhynchos) captured from July to December 2002 at Ueno Zoo, Tokyo were identified as Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Enterobacter agglomerans, Pseudomonas maltophila, Staphylococcus spp., Micrococcus spp., and Streptococcus spp. E. coli showed the highest rate of isolation (21.6%). In an in vitro susceptibility test for 29 isolates of E. coli to 14 antimicrobial agents, all the isolates were resistant to penicillin G, vancomycin, erythromycin, lincomycin, bicozamycin, sulfadimethoxine, and olaquindox. Several isolates of them were also resistant to tetracycline, oxytetracycline, streptomycin, chloramphenicol, and ampicillin. Twenty-nine isolates were divided into 19 serogroups and the most frequently identified serogroups were O8, O114 and O144, which showed the same multidrug-resistant patterns. PMID:15528866
Microorganisms from 45 jungle crows (Corvus macrorhynchos) captured from July to December 2002 at Ueno Zoo, Tokyo were identified as Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Enterobacter agglomerans, Pseudomonas maltophila, Staphylococcus spp., Micrococcus spp., and Streptococcus spp. E. coli showed the highest rate of isolation (21.6%). In an in vitro susceptibility test for 29 isolates of E. coli to 14 antimicrobial agents, all the isolates were resistant to penicillin G, vancomycin, erythromycin, lincomycin, bicozamycin, sulfadimethoxine, and olaquindox. Several isolates of them were also resistant to tetracycline, oxytetracycline, streptomycin, chloramphenicol, and ampicillin. Twenty-nine isolates were divided into 19 serogroups and the most frequently identified serogroups were O8, O114 and O144, which showed the same multidrug-resistant patterns.
In this work, human serum albumin (HSA) stabilized gold nanoclusters (HSA-AuNCs) with reddish photoluminescence were used as sensing probes for pathogenic bacteria including Enterobacter cloacae, Escherichia coli J96, Pseudomonas aeruginosa, pandrug-resistant Acinetobacter baumannii (PDRAB), Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Streptococcus pyogenes, and vancomycin-resistant Enterococcus faecalis (VRE). We discovered that HSA-AuNCs have unique affinity with S. aureus and MRSA. In addition to demonstrating the selective sensing ability of HSA-AuNCs toward S. aureus and MRSA, the binding peptide motifs identified from HSA-AuNCs were characterized by mass spectrometry. The identified binding peptides were further used as the reducing and stabilizing agents for generation of peptide-bound AuNCs (Pep-AuNCs). The generated Pep-AuNCs were demonstrated to have the binding affinities with S. aureus and MRSA. PMID:23088348
Summary Streptococcus mutans, a major etiological agent of dental caries, frequently causes systemic disease, such as subacute bacterial endocarditis, if it enters the bloodstream. In this study, the production pathways of the proinflammatory cytokines, tumor necrosis factor- (TNF-) and interleukin-1 (IL-1), induced by S.mutans in mouse macrophage were examined using a quantitative real-time polymerase chain reaction and an enzyme-linked immunosorbent assay. The S.mutans stimulated the expression of TNF- and IL-1 mRNA at a multiplicity of infection of 1-:-100, which increased at 2 and 4-h, respectively, to 24-h. It also induced the production of high levels of the TNF- and IL-1 proteins, which increased at 2-h and reached a peak at 4 and 24-h, respectively. Nuclear factor-B (NF-B) was acti...
Streptococcus mutans is the primary etiological agent responsible for dental caries. Microfluidic devices have been used to provide a level of control over bacterial microenvironments under laminar flow conditions. In this study, we used a microfluidic device packed with glass beads to simulate the interproximal space, which is the space between the teeth. In the device, the effects of environmental factors, such as sucrose and metal ions, on S. mutans attachment and biofilm formation were quantitatively measured using confocal laser scanning microscopy and atomic force microscopy. We determined that sucrose was required for both bacterial attachment and exopolysaccharide (EPS) production in S. mutans. These results suggest that the in vivo condition between the teeth was successfully mimi...
BACKGROUND: We conducted a prospective, observational study in Barcelona (Spain) to determine changes in the spectrum of adult patients with bacterial meningitis (BM) over a 29-year period. METHODS: The observation was divided into two periods: 1982-1995 (I) and 1996-2010 (II). All patients underwent clinical examination on admission and at discharge following a predefined protocol. RESULTS: We evaluated 635 episodes of BM. The most frequent etiologic agents were Neisseria meningitidis and Streptococcus pneumoniae in periods I and II, respectively. Patients in period II were older (Median: 47.5 [95%CI: 23.0-64.5] vs. 58.0 [39.0-73.0] years, P conditions (39.1% vs. 62%, P terms of population affected, aetiology, and management, but not in terms of its overall mortality rate and appearance of post-meningitic sequelae. PMID:23168216
Pneumococcal meningitis post cochlear implantation: Development of an animal model in the guinea pig
In 2002 an increased number of cochlear implant related meningitis cases was reported by the U. S. Food and Drug Administration (FDA). The most commonly identified causative agent was Streptococcus pneumoniae. Although most cases of meningitis were related to a special electrode design, the risk for post-operative pneumococcal meningitis might nonetheless be enhanced by opening of the cochlea during implantation. In the present study, a threshold model for middle ear inoculation of S. pneumoniae was established in the guinea pig after cochlear implantation to assess the post-operative risk of meningitis. Guinea pigs were implanted unilaterally with a silicone cochlear implant electrode dummy. Five weeks after implantation, animals were challenged via the middle ear with a clinically releva...
Staphylococcus aureus: is it a pathogen of acute bacterial sinusitis in children and adults?
Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are the etiologic agents of acute bacterial sinusitis (ABS). Staphylococcus aureus has been an uncommon cause of ABS despite its frequent occupancy within the anterior nares. A quantitative culture of a maxillary sinus aspirate is the gold standard for determining etiology of ABS. Cultures of the middle meatus cannot be used as a surrogate for a maxillary sinus aspirate in children with ABS, although they may be used in adults if interpretation is confined to usual sinus pathogens. Recent studies highlighting S. aureus as a major pathogen in ABS should be interpreted cautiously. Most isolates in recent pediatric studies were derived from cultures of the middle meatus. The range of reported results for the incidence of S. aureus as a cause of ABS in adults is similar to the results reported for staphylococcal colonization of the middle meatus in healthy adults. PMID:22198792
Novel DNA gyrase inhibitors: Microbiological characterisation of pyrrolamides.
Pyrrolamides are a novel class of antibacterial agents that target DNA gyrase, resulting in inhibition of DNA synthesis and bacterial cell death. In these studies, advanced compounds were shown to have potent in vitro activity against selected Gram-positive and Gram-negative pathogens, including meticillin-resistant Staphylococcus aureus, meticillin- and quinolone-resistant S. aureus, vancomycin-resistant enterococci, penicillin-resistant Streptococcus pneumoniae and ?-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis. Representatives of the class were demonstrated to be bactericidal, with frequencies of spontaneous resistance ?1×10(-7) when plated at concentrations equivalent to their minimum inhibitory concentration. Mode of action studies suggested that the activity of these compounds is due to inhibition of the GyrB subunit of DNA gyrase in key pathogens. The antibacterial activity, spectrum and mode of action of these compounds underscore the promise of the pyrrolamide series as attractive candidates for the treatment of several clinical indications, including respiratory and soft tissue infections. PMID:23142086
Objectives. Solithromycin (formerly CEM-101) is a novel fluoroketolide with potent activity against bacterial pathogens that are susceptible or resistant to other MLSB-ketolide agents. The objective of this study was to assess the activity of solithromycin and comparator antimicrobials against a large number and variety of contemporary clinical bacterial pathogens collected in the United States (USA) and Europe during 2009.Method. During 2009, a total of 10,670 non-duplicated clinical isolates were collected from 52 medical centers located in the USA (27 centers; 6228 isolates) and Europe (25 centers; 4442 isolates). Susceptibility testing and interpretation were performed using CLSI reference methods.Results. Among 1363 Streptococcus pneumoniae isolates, 99.9% of the strains displayed sol...
Antibiotic therapy for pneumonia in the pediatric population
Approximately 4% of children aged less than 5 years and 2% of 5-10 year olds suffer from pneumonia every year in Western countries. Half of the under 5 year olds but less than 10% of the over 5-year-old children need hospital care. The available knowledge regarding the etiology of pneumonia comes from serological studies. Respiratory viruses are predominant in under 5 years olds and Mycoplasma pneumoniae in children over 5 years of age. Mixed infections with two or more causative agents are common. Streptococcus pneumoniae is common at all ages, and complications are usually associated with pneumococcal infections or co-infections. Pneumococcal resistance to penicillins and macrolides is a globally expanding problem. The microbe-specific diagnosis of pneumonia is difficult and, therefore, ...
The LEADER program monitors the in vitro activity of linezolid and comparator agents across the United States using reference broth microdilution and supportive molecular susceptibility-based investigations. This report summarizes the data from the 2010 program, the seventh consecutive year. A total of 61 medical centers from the USA including 7 medical centers specializing in children's healthcare provided a total of 6801 Gram-positive pathogens. The medical centers represented all 9 US Bureau of Census geographic regions. The organisms tested by reference broth microdilution were 3105 Staphylococcus aureus, 944 coagulase-negative staphylococci (CoNS), 934 Enterococci, 803 Streptococcus pneumoniae, 604 b-haemolytic streptococci, and 411 viridans group and other streptococci. The MIC90 val...
Investigation of 1789 field-collected adult ticks in Egypt for the presence of microorganisms revealed the following: the protozoan, Babesia bigemina, B. canis; Theileria annulata, and the rickettesia Aegyptianella pullorum (Carpano) were found in the saliva and the mid-guts smears of eight ixodid and two argasid tick species. The infected percent was higher in cattle and dog ticks than it was in fowl ticks; it was also higher in salivary glands (S) than in the midguts (M). Identification of protozoa using microscopic image analysis, showed that: Hyalomma spp. (Koch) were infected with T. annulata; the genera Boophilus (Curtice) and Rhipicephalus Koch were infected with B. bigemina, and B. canis respectively; Argas spp. (Latreille) were infected with A. pullorum. The bacterial disease agents: Staphylococcus, Streptococcus and Yersinia were detected in (S) and (M) of eight ixodids and one argasid tick species; Bacillus was only found in H. anatolicum excavatum, (Koch). Escherichia coli was isolated only from A. persicus (Oken) midguts. PMID:17985586
Influence of sweetening agents in solution on dental caries in desalivated rats.
Sucralose (trichlorogalactosucrose), sorbitol and aspartame in drinking water induced little or no caries in desalivated rats infected with Streptococcus sobrinus and Actinomyces viscosus and receiving their essential nutrition by gastric gavage. In contrast, sucrose and fructose induced extensive decay. Only sucrose could sustain implantation of Strep. sobrinus in these animals. The populations of A. viscosus were sparse (0.3-0.5%) in the animals given fructose and sucrose. Large populations of A. viscosus occurred in the controls and in those given sucralose, sorbitol and aspartame. In a second experiment, where animals were also desalivated and receive diet 2000 ad libitum, sucrose in solution promoted caries whereas sucralose, aspartame and saccharin were without effect. Addition of 10 parts/10(6) F overcame the caries-promoting effect of sucrose in solution. There was no interaction between fluoride and other sweetening agents that affected the incidence of caries. PMID:2124801
Infecção fulminante pós-esplenectomia/ Overwhelming postsplenectomy infection
Abstract in portuguese RACIONAL: A esplenectomia, em qualquer faixa etária e por qualquer indicação, aumenta o risco de morte por infecção fulminante. OBJETIVO: Avaliar a definição, a etiologia, a incidência, os fatores de risco e a profilaxia da infeção fulminante pós-esplenectomia, bem como os métodos existentes para preservação de tecido esplênico quando a esplenectomia total faz-se necessária. MÉTODO: Revisão bibliográfica. RESULTADOS: Os agentes etiológicos mais freqüe (more) ntemente encontrados nesse quadro séptico são Streptococcus pneumoniae, Haemophilus influenza e tipo B, e Neisseria meningitidis. Outras bactérias, como Escherichia coli, Streptococcus b-hemolítico, Staphylococcus aureus e Pseudomonas sp, também representam risco significativo. Similarmente, grande variedade de agentes, incluindo outros microrganismos entéricos Gram-negativos e patógenos não-bacterianos, também é relatada esporadicamente. A profilaxia situa-se em três categorias principais: educação dos pacientes, imunoprofilaxia e quimioprofilaxia. Contudo, essas medidas não são suficientes para debelar o grande risco de desenvolvimento dessa enfermidade. Quando a esplenectomia total for necessária, o auto-implante esplênico heterotópico parece constituir a única alternativa para preservação de tecido esplênico. Estudos clínicos e experimentais têm mostrado que, após um período de regeneração, desenvolve-se tecido esplênico viável, com características estruturais similares a um baço normal e com preservação da função imune esplênica. CONCLUSÕES: Com a caracterização mais detalhada da infecção fulminante pós-esplenectomia, a indicação para esplenectomia total, tanto no trauma, como em diversas enfermidades, vem nitidamente decrescendo. Métodos profiláticos foram desenvolvidos visando à minimização dos efeitos dessa grave enfermidade. Muitas pesquisas vêm tentando determinar o grau de imunocompetência que o enxerto esplênico autógeno pode prover ao hospedeiro, em resposta à invasão bacteriana. Abstract in english BACKGROUND: Splenectomy performed at any age and for any reason increases the risk for death due to overwhelming infection. AIM: To evaluate definition, etiology, incidence, risk factors and prophylaxis of overwhelming postsplenectomy infection, as well as the methods related to splenic tissue preservation when total splenectomy is necessary. METHOD: Bibliographic review. RESULTS: The etiological agents more frequently found are Streptococcus pneumoniae, Haemophilus influ (more) enza and type B, and Neisseria meningitidis. Other bacteria like Escherichia coli, Streptococcus b-hemolytic, Staphylococcus aureus and Pseudomonas sp represent a significant risk as well. In addition, a great variety of agents including other enteric Gram-negative microorganisms and non-bacteria pathogens can also be sporadically identified. The prophylaxis is based on three main aspects: patient's education, immune prophylaxis and chemical prophylaxis. However these are not enough to prevent the higher risk of developing sepsis. When total splenectomy is unavoidable, heterotopic splenic autotransplantation seems to be the only alternative for splenic tissue preservation. According to clinical and experimental studies, the splenic autotransplanted tissue present a similar structure to a normal spleen and preserve the splenic immune function. CONCLUSIONS: The high risk of overwhelming postsplenectomy infection, reduced the indication for total splenectomy, in trauma and several diseases. Prophylactic methods have been developed to minimize the effects of the sepsis. Several researches have been done to determine the immunocompetence of autogenous splenic grafts in response to bacteria invasion.
Ethanolic extracts of eight medicinal plants commonly used in folk medicine were tested for their antibacterial activity against four Gram positive strains (Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis and, Streptococcus pneumoniae) and six Gram negative strains (Escherichia coli, Proteus vulgaris, Proteus mirabilis. Salmonella typhi para A, Salmonella typhi para B and Shigella dysenteriae) that were obtained from different pathological laboratories located in Karachi, Pakistan. Disc diffusion method was used to analyze antibacterial activity. Out of eight, five medicinal plants showed antibacterial activity against two or more than two microbial species. The most effective antimicrobial plant found to be Punica granatum followed by Curcuma zedoaria Rosc, Grewia asiatica L and Carissa carandas L, Curcuma caesia Roxb respectively. From these results, it is evident that medicinal plants could be used as a potential source of new antibacterial agents. PMID:22713958
Summary Gingivitis and dental caries are two of the most predominant diseases in humans. Both conditions are easily treated with the removal of the plaque biofilm by brushing or the use of oral hygiene products. In both cases, pathogenic taxa found within the plaque biofilm are the causal agents of the disease. Actinomyces naeslundii, Fusobacterium nucleatum and Prevotalla intermedia have all been implicated in the development of gingivitis, while Streptococcus mutans is the main organism associated with dental caries. Many studies have so far focused on the use of culture methods to detect and enumerate the pathogenic taxa within plaque samples. However, these methods are both labour intensive and biased towards culturable taxa. In the present study, a novel high-throughput multi-triplex ...
Abstract Berberine the main antibacterial substance in the rhizome of Coptis chinensis Franch, is used as an antimicrobial agent for a long time. This study was carried out to investigate the potential of berberine alone or in combination with enrofloxacin against six common fish pathogens for use in fish disease management in aquaculture. The minimum inhibitory concentrations (MICs) of berberine hydrochloride against Aeromonas hydrophila, Pseudomonas fluorescens, Vibrio vulnificus, Edwardsiella ictaluri, Escherichia coli and Streptococcus agalactiae were determined and to be >500, >500, >500, 300, 400 and 100 mg mL-1 respectively. The minimal bactericidal concentrations (MBCs) of berberine hydrochloride to E. coli, E. ictaluri and S. agalactiae were 300-500 mg mL-1. In combination with en...
D-alanylation of lipoteichoic acid contributes to the virulence of Streptococcus suis.
We generated by allelic replacement a DeltadltA mutant of a virulent Streptococcus suis serotype 2 field strain and evaluated the contribution of lipoteichoic acid (LTA) d-alanylation to the virulence traits of this swine pathogen and zoonotic agent. The absence of LTA D-alanylation resulted in increased susceptibility to the action of cationic antimicrobial peptides. In addition, and in contrast to the wild-type strain, the DeltadltA mutant was efficiently killed by porcine neutrophils and showed diminished adherence to and invasion of porcine brain microvascular endothelial cells. Finally, the DeltadltA mutant was attenuated in both the CD1 mouse and porcine models of infection, probably reflecting a decreased ability to escape immune clearance mechanisms and an impaired capacity to move across host barriers. The results of this study suggest that LTA D-alanylation is an important factor in S. suis virulence. PMID:18474639
Streptococcus suis, a major pathogen of swine, is an emerging zoonotic agent which causes meningitis and septic shock. In this study, we investigated the ability of S. suis mutant strain (SRTDeltaA) lacking the sortase A gene (srtA) to interact with host cells and extracellular matrix (ECM) proteins, as well as its virulence in a mouse infection model. We demonstrated that mutant SRTDeltaA had reduced capacity to adhere to and invade porcine brain microvascular endothelial cells compared to the wild-type strain. In addition, mutant SRTDeltaA also showed significantly less adherence to plasma fibronectin, cellular fibronectin and collagen type I. However, disruption of srtA had little effect on the virulence of S. suis in a mouse intraperitoneal model of infection. These results indicate that surface proteins anchored by sortase A are required for a normal level of bacterial binding. However, other factors may also be important for S. suis virulence and interaction with host tissues. PMID:17954016
Streptococcus suis, a major pathogen of swine, is an emerging zoonotic agent which causes meningitis and septic shock. In this study, we investigated the ability of S. suis mutant strain (SRTDA) lacking the sortase A gene (srtA) to interact with host cells and extracellular matrix (ECM) proteins, as well as its virulence in a mouse infection model. We demonstrated that mutant SRTDA had reduced capacity to adhere to and invade porcine brain microvascular endothelial cells compared to the wild-type strain. In addition, mutant SRTDA also showed significantly less adherence to plasma fibronectin, cellular fibronectin and collagen type I. However, disruption of srtA had little effect on the virulence of S. suis in a mouse intraperitoneal model of infection. These results indicate that surface p...
Streptococcus suis is a major pathogen of swine, causing mainly meningitis, and it also represents an emerging zoonotic agent. We investigated its ability to induce the release of pro-inflammatory cytokines and chemokines by porcine brain microvascular endothelial cells (PBMEC). We demonstrated that live S. suis induced a strong release of interleukin (IL)-6 and IL-8 by PBMEC. We showed that the suilysin (hemolysin) was largely responsible for such stimulation, although cell wall components also contribute to cell stimulation but to a considerably lower extent. Interestingly, IL-8 production by PBMEC became undetectable by increasing either the incubation time or bacterial concentration of certain live S. suis strains. We further demonstrated that this decrease of IL-8 levels was probably ...
Short communication: Characterization of microflora in Mexican Chihuahua cheese
This work was performed to identify the bacterial species present in 10 Chihuahua cheeses obtained from commercial producers in Mexico using 16S rRNA gene analysis. As expected, some of the agar media initially used for isolation were not very selective, supporting the growth of several unrelated bacterial species. Sequence analysis identified potential pathogens, including Escherichia coli and Staphylococcus aureus, in all raw milk samples and 2 pasteurized milk samples. Streptococcus thermophilus and Lactococcus lactis ssp. lactis were identified in 9 and 6 samples, respectively, and would serve as acidifying agents during cheese production. Lactobacilli were identified in all cheeses, with the most prevalent being Lactobacillus plantarum identified in 7 raw milk and 1 pasteurized milk c...
Structural insights into catalysis by C-S lyase from Streptococcus anginosus
Abstract Hydrogen sulfide (H2S) is a causative agent of oral malodor and may play an important role in the pathogenicity of oral bacteria such as Streptococcus anginosus. In this microorganism, H2S production is associated with C-S lyase (Lcd) encoded by lcd gene, which is a pyridoxal 5--phosphate (PLP)-dependent enzyme that catalyzes the ,-elimination of sulfur-containing amino acids. When Lcd acts on L-cysteine, H2S is produced along with pyruvate and ammonia. To understand the H2S-producing mechanism of Lcd in detail, we determined the crystal structures of substrate-free Lcd (internal aldimine form) and two reaction intermediate complexes (external aldimine and -aminoacrylate forms). The formation of intermediates induced little changes in the overall structure of the enzyme and in the...
Summary Antimicrobial peptides (AMPs) are among the repertoire of host innate immune defenses. In the oral cavity, several AMPs are present in saliva and have antimicrobial activities against oral bacteria, including Streptococcus mutans, a primary etiological agent of dental caries. In this study, we hypothesized that unique S.mutans strains, as determined by DNA fingerprinting from sixty 13-year-old subjects with or without experience of caries, would have different susceptibilities to -defensins-1-3 (HNP-1-3), -defensins-2-3 (HBD-2-3) and LL-37. The salivary levels of these peptides in subjects were also measured by enzyme-linked immunosorbent assays. We found that S.mutans strains from children with active caries showed greater resistance to salivary HNP-1-2, HBD-2-3 and LL-37 at varyi...
In this study, four essential oils?cinnamon oil, leech lime oil, lemongrass oil, and turmeric oil?were examined for their antimicrobial activities against Streptococcus iniae, a bacterium that is pathogenic in fish, in which it causes streptococcosis. Cinnamon oil was the most potent antimicrobial agent among these oils, with a minimal inhibitory concentration (MIC) of 40 ?g/ml. By using gas chromatography?mass spectrometry (GC?MS), it was found that the major components of cinnamon oil were cinnamaldehyde (90.24), limonene (2.42%), cinnamyl acetate (2.03%), linalool (1.16%), and ?-terpineol (0.87%). Of these compounds, only cinnamaldehyde exhibited antimicrobial activity against S. iniae, with an MIC of 20 ?g/ml. In an in vivo trial, no mortality was apparent in fish fed on fish diets sup...
Evaluation of a selective medium for isolation of Haemophilus pleuropneumoniae.
Crystal violet, lincomycin, spectinomycin and bacitracin were evaluated as selective agents in media for isolation of Haemophilus pleuropneumoniae. No single antimicrobial agent or combination of two or more inhibited all non-Haemophilus strains (Escherichia coli, Pasteurella haemolytica, Pasteurella multocida, Streptococcus faecalis, Streptococcus equisimilis and Staphylococcus aureus) without marked suppression of 16 H. pleuropneumoniae strains. A medium containing 1 micrograms/mL of crystal violet, 1 microgram/mL of lincomycin, 8 micrograms/mL of spectinomycin and 128 micrograms/mL of bacitracin inhibited one E. coli strain and the Gram-positive strains while H. pleuropneumoniae strains were suppressed to a minor degree only. Haemophilus pleuropneumoniae was isolated on the selective medium on three occasions from the nose or pharynx of two out of eight experimentally inoculated pigs. Haemophilus pleuropneumoniae was recovered from the nose of only two pigs at necropsy and from tonsil of one, whereas the lower airways in most pigs and the lung lesions in all pigs were positive. There was no advantage to using the selective medium for the recovery of H. pleuropneumoniae at necropsy from these eight experimentally infected pigs, probably because other bacteria were absent or present in very low numbers in the tissues with H. pleuropneumoniae. The isolation rate on selective medium was higher than the rate on non-selective medium (p less than or equal to 0.1; chi 2 test) when the airways of slaughtered pigs were cultured. This was likely due to a high degree of contamination. Dry swabs placed in tryptone yeast extract with nicotinamide-adenine-dinucleotide gave a significantly higher recovery rate than commercial Culturette swabs in modified Stuart's transport medium.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6230143
Abstract in spanish Se describe un caso de meningitis por Streptococcus suis en un paciente inmunocompetente. Presentaba astenia, debilidad generalizada, fiebre (39 °C), vómitos, deterioro del sensorio y desorientación témporo-espacial. Los cultivos de sangre (2/2) y de líquido cefalorraquídeo fueron positivos. La identificación preliminar se realizó utilizando las pruebas bioquímicas convencionales y fue completada en el Servicio Bacteriología Especial del INEI-ANLIS "Dr. Carlos G (more) . Malbrán". Se comenzó el tratamiento con ampicilina y ceftriaxona. El microorganismo aislado demostró sensibilidad a ampicilina, cefotaxima y vancomicina. El paciente evolucionó favorablemente, pero se comprobó leve hipoacusia. Reingresó a los 4 meses con marcha atáxica, anacusia en oído izquierdo e hipoacusia en oído derecho. Continúa con seguimiento neurológico y audiométrico. Retrospectivamente se constató el contacto del paciente con cerdos. Se destaca la importancia de la anamnesis para alertar la sospecha de este agente etiológico en meningitis y bacteriemias. Abstract in english A case of Streptococcus suis meningitis is described in an immunocompetent patient presenting asthenia, general weakness, fever, vomiting, sensory deterioration and temporospatial disorder. The cerebrospinal fluid and two blood cultures (2/2 bottles) were positive. The isolate was preliminary identified by conventional biochemical tests, and the identification was completed at the Special Bacteriology Service of INEI-ANLIS "Dr. Carlos G. Malbrán". Ampicillin and ceftriax (more) one treatment was initiated. The isolate was susceptible to ampicillin, cefotaxime and vancomycin. The patient experienced a good outcome but suffered hearing loss. However, after four months he returned with walking ataxia, deafness in his left ear, and hearing loss in the right ear. The patient’s retrospective exposure to pigs had been verified. It is important to evaluate predisposing and epidemiologic factors in order to alert about the possible presence of this etiological agent in cases of meningitis or bacteremia.
Abstract in portuguese Foram estudadas 271 crianças com idade inferior a 15 anos, com diagnóstico de meningencefalite bacteriana aguda (MBA), no período 1980 -- 1990. Os pacientes foram divididos em dois grupos, conforme não tivessem recebido tratamento prévio (STP), 153 casos, e os que receberam tratamento prévio (CTP), 118 casos. Ocorreram diferenças significativas em relação a identificação do agente etiológico, que foi maior no grupo STP, e em relação a ocorrência de ventricu (more) lite, maior no grupo CTP. Ocorreu óbito em 19,5% dos 271 casos, com predomínio em crianças de idade abaixo de 12 meses (29,7%) e nos pacientes com MBA por Streptococcus pneumoniae. As manifestações epilépticas e as paresias na fase aguda da MBA predominaram em crianças de idade abaixo de 1 ano. Foram identificados e tratados do ponto de vista neurocirúrgico as ventriculites, higroma subdural, hidrocefalia, empiema subdural e abscesso cerebral. Abstract in english We studied 271 children under age of 15 with diagnosis of acute bacterial meningencephalitis treated at Medical School in Ribeirão Preto, University of São Paulo, between 1980 and 1990. The patients were divided in two groups: 1) those who had not received previous antibiotics treatment (NTP), with 153 cases; and 2), those who had received previous antibiotics treatment (PT), with 118 cases. The etiological agent was more frequently identified in NPT group, while ventri (more) culitis was more frequent in PT group. Mortality rate accounted for 19,5% of all cases, and 29.7% of children under 12 months of age. Acute meningitis caused by Streptococcus pneumoniae was frequently followed by increased mortality. Convulsive disorders and hemiparesis predominante among children under 12 months of age. On the neurosurgical point of view, ventriculitis, subdural hygroma, hydrocephalus, subdural empyema and brain abscess were identified and treated
Abstract in spanish Streptococcus suis es un coco anaerobio facultativo, considerado un importante agente asociado a meningitis, artritis, endocarditis y neumonía en cerdos. En este trabajo se realizó el aislamiento de S.suis a partir de diferentes condiciones clínicas como neumonía, abscesos en articulaciones y tonsilas de animales asintomáticos. Se identificaron 14 cepas de S. suis: 11 a partir de pulmones, 2 de abscesos y 1 de tonsila. Las cepas mostraron diferentes patrones de prueb (more) as bioquímicas. El gen que codifica para la hemolisina denominados suilisina (syl) se detectó por PCR solamente en 5 cepas de las cuales 4 proceden de pulmón y una de tonsila. Sin embargo, en los aislamientos procedentes de abscesos y asociados a artritis no se detectó la presencia de este gen, lo cual muestra un comportamiento similar a las cepas presentes en Norte América syl -, asociadas a enfermedad invasiva. Abstract in english Streptococcus suis is a facultative anaerobic coccus considered an important agent associated to meningitis, arthritis, endocarditis and pneumonia. In this work, the isolation of S. suis from different clinical conditions such as pneumonia, joint and tonsil in asymptomatic animals was carried out. Fourteen strains of S. suis were identified: 11 from lungs, 2 from abscess and 1 from tonsils. The strains showed different pattern of biochemistry test. The syl gene codifying (more) for suylisin was detected by PCR only in 5 strains, four coming from lung and one from tonsil. However, in the isolations from abscess and associated to arthritis, the presence of this gene was not detected showing a similar behaviour to the strains from North America (syl -) associated to invasive disease.
Context: Dental caries are an infectious oral bacterial disease caused by cariogenic streptococci. These streptococci inhabit dental biofilms which comprise insoluble glucans. Objective: To prevent dental caries, nisin, a suitable agent active against Gram-positive bacteria, was examined in vitro for its ability to suppress insoluble glucan-biofilm synthesis by cariogenic streptococci. Materials and methods: To investigate glucan-biofilm synthesis by a typical cariogenic streptococcus, Streptococcus mutans 10449, the naked form of nisin was loaded onto a 96-well microplate in vitro model. To prolong the efficacy of nisin as a preventive agent, liposome-encapsulated nisin (nisin-liposome) was examined for its ability to inhibit the synthesis of glucan-biofilms on microplates. Results: Naked nisin (100 pmol) completely suppressed insoluble glucan-biofilm synthesis by S. mutans 10449 following 1?h cultivation in 96-well microplates. The concentration of nisin-liposome required for the efficacious inhibition of glucan-biofilm synthesis was four times lower than that of naked nisin following 2?h cultivation. In particular, nisin-liposome (30 pmol nisin equivalent) prolonged the inhibitory activity of nisin against glucan-biofilm synthesis by S. mutans 10449 for up to 6?h, while naked nisin (30 pmol) gradually lost this inhibitory activity over the same period. In vitro release assay of nisin from the liposome showed that 76% nisin was released within 6?h. Discussion and conclusion: The findings indicate the usefulness of nisin-liposome for the sustained release of nisin. Thus, nisin-liposome could play a potential role in preventive medicine as an inhibitor of the glucan-biofilm synthesis. PMID:23116173
Etiología bacteriana de las infecciones respiratorias agudas en pacientes VIH/SIDA
Abstract in spanish Se estudió un total de 63 pacientes VIH/SIDA con infecciones respiratorias agudas (IRA) ingresados en el Hospital del Instituto de Medicina Tropical "Pedro Kourí" en el período comprendido de enero a agosto de 1997. Se procesó un total de 545 muestras: 153 esputos, 158 hemocultivos, 110 exudados faríngeos, 61 exudados nasales y 63 exudados óticos. Se estudió la correlación de los resultados obtenidos por la técnica de naranja de acridina, la coloración de Gram y (more) cultivo. Los agentes bacterianos más frecuentes causantes de IRA del total de cepas aisladas fueron: Pseudomonas aeruginosa (29.65 %), Staphylococcus aureus (27,14 %) y Streptococcus pneumoniae (9,04 %). Los microorganismos más frecuentemente asociados con bacteriemias fueron: Staphylococcus epidermidis (38,70 %), Staphylococcus aureus (16,13 %), Pseudomonas aeruginosa (12,90 %), y Salmonella tipo b (12,90 %). La técnica de naranja de acridina resultó ser la más adecuada en el diagnóstico presuntivo de bacteriemia con 95 % de certeza, pues tiene un rango de positividad entre 40, 56 y 50, 56 con una p Abstract in english A total of 63 HIV/AIDS patients with acute respiratory infections admitted to "Pedro Kourí" Tropical Medicine Institute´s hospital from January to August 1997 were studied. 545 samples in all were processed: 153 sputa, 150 hemocultures, 110 pharyngeal exudates, 61 nasal exudates and 63 otic exudates. The correlation of the results from the acridine orange technique, Gram staining and culture was studied. The most frequent bacterial agents causing acute respiratory infec (more) tions in the group of isolated strains were: Pseudomonas aeruginosa (29.65 %), Staphylococcus aureus (27.14 %) and Streptococcus penumoniae (9.04 %). The microorganisms more frequently associated with bacteriemias were: Staphylococcus aureus (16.13 %), Pseudomonas aeruginosa (12.90 %) and Type b Salmonella (12.90 %). The acridine orange technique was the most effective in presumptive diagnosis of bacteriemia with 95 % certainty since it showed a positivity range from 40, 56 to 50, 56, with a p
Treatment of bacterial meningitis: an update.
INTRODUCTION: The introduction of protein conjugate vaccines for Haemophilus influenzae type b (Hib), Streptococcus pneumoniae (S. pneumoniae) and Neisseria meningitidis (N. menigitidis) has changed the epidemiology of bacterial meningitis. Bacterial meningitis continues to be an important cause of mortality and morbidity, and our incomplete knowledge of its pathogenesis and emergence of antimicrobial resistant bacteria contribute to such mortality and morbidity. An early empiric antibiotic treatment is critical for the management of patients with bacterial meningitis. AREAS COVERED: This article gives an overview on optimal treatment strategies of bacterial meningitis, along with considerations of new insights on epidemiology, clinical and laboratory findings supportive of bacterial meningitis, chemoprophylaxis, selection of initial antimicrobial agents for suspected bacterial meningitis, antimicrobial resistance and utility of new antibiotics, status on anti-inflammatory agents and adjunctive therapy, and pathogenesis of bacterial meningitis. EXPERT OPINION: Prompt treatment of bacterial meningitis with an appropriate antibiotic is essential. Optimal antimicrobial treatment of bacterial meningitis requires bactericidal agents able to penetrate the blood-brain barrier (BBB), with efficacy in cerebrospinal fluid (CSF). Several new antibiotics have been introduced for the treatment of meningitis caused by resistant bacteria, but their use in human studies has been limited. More complete understanding of the microbial and host interactions that are involved in the pathogenesis of bacterial meningitis and associated neurologic sequelae is likely to help in developing new strategies for the prevention and therapy of bacterial meningitis. PMID:22984938
Análisis de la eficacia de agentes químicos de desinfección en materiales elastoméricos
Abstract in portuguese O objetivo deste estudo in vitro foi avaliar a eficácia de agentes de desinfecção indicados para polissulfetos, poliéteres e siliconas de condensação e adição. Foram confeccionadas noventa amostras de cada material, sendo cada trinta contaminadas com Streptococcus mutans, Staphylococcus aureus ou Candida albicans. De cada solução microbiana foram retiradas dez amostras do polissulfeto e de ambas as siliconas, que foram imersas por dez minutos no glutaraldeído a (more) 2% e outras dez imersas em água destilada estéril (controle negativo). Após nova lavagem em água destilada, as amostras foram transferidas para meios de cultura estéreis. As dez amostras restantes não foram submetidas ao agente de desinfecção e foram transferidas para meios associados a agentes antimicrobianos específicos (controle positivo). A turbidez dos meios de cultura foi avaliada como indicativo de crescimento microbiano após incubação por 24 h a 37O C e realizou-se a diluição e semeadura nas placas de Petri para contagem de colônias. Para o poliéter foi executado o mesmo procedimento, porém o agente de desinfecção empregado foi o hipoclorito de sódio a 1%. Não houve turvação comprobatória de crescimento bacteriano em nenhum dos meios da cultura que continham corpos de prova submetidos aos agentes de desinfecção. Concluiu-se que o glutaraldeído a 2% é um agente de desinfecção eficaz para o polissulfeto e para as siliconas por adição e por condensação, assim como o hipoclorito a 1% é eficaz para o poliéter, para os microorganismos testados. Abstract in spanish El objetivo de este estudio fue evaluar la eficacia de agentes de desinfección indicados para polisulfuros (mercaptanos), poliéteres y siliconas por condensación y por adición. Fueron confeccionadas noventa muestras de cada material, siendo treinta de ellas contaminadas con Streptococcus mutans o Staphylococcus aureus o Candida albicans. De cada solución microbiana fueron retiradas diez muestras del polisulfeto y de ambas las siliconas, que fueron inmersas por diez m (more) inutos en glutaraldehído al 2% y otras diez inmersas en agua destilada estéril (controle negativo). Después de un nuevo lavado en agua destilada, las muestras fueron transferidas a medios de cultivo estériles. Las diez muestras restantes no fueron sometidas al agente de desinfección y fueron transferidas a medios asociados a agentes antimicrobianos específicos (control positivo). La turbidez de los medios de cultivo fue evaluada como indicativo del crecimiento microbiano siguiéndose a la incubación por 24 h a 37O C y se realizó la dilución y sembrado en placas de Petri para contar las colonias. Para el poliéter fue ejecutado el mismo procedimiento, pero el agente de desinfección usado fue el hipoclorito de sodio a 1%. No hubo turbidez comprobatoria del crecimiento microbiano en ninguno de los medios de cultivo que contenían los especimenes sometidos a los agentes de desinfección. Se concluyó que el glutaraldehído al 2% es un agente de desinfección eficaz para el polisulfuro y para las siliconas por adición y por condensación, así como el hipoclorito a 1% es eficaz para el poliéter, para los microorganismos evaluados. Abstract in english The aim of this in vitro study was to evaluate the disinfection efficacy of elastomeric impression materials such as polysulfides, polyethers, condensation and addition silicones. Ninety samples of each material were made and every thirty samples contaminated with Streptococcus mutans or Staphylococcus aureus or Candida albicans. From each microbial solution there were taken ten samples of polysulfide and of both silicones which were immersed for ten minutes in a 2% gluta (more) raldehyde solution and other ten immersed in sterile distilled water (negative control). After being washed again in distilled water, the samples were transferred to sterile culture medium. The last ten samples were not submitted to any disinfection agent and were transferred to mediums associated with specific anti-microbial agents (positive control). The turbidity of the culture mediums was evaluated as an indication of the microbial growth after a period of 24-hour incubation at 37oC and the dilution and seeding in Petri dishes were done to count the colonies. The same procedure was done for the polyether, but the disinfection agent used was 1% sodium hypoclorite. There was no proved turbidity of the microbial growth in any of the culture mediums which had samples submitted to the disinfection agents tested. It was concluded that the 2% glutaraldehyde is an effective disinfection agent to polysulfides and to both condensation and addition silicones, as well as 1% sodium hypoclorite is effective to polyether, for the tested microorganisms.
We present here three cases in which morphological changes and/or a decreased number of Streptococcus pneumoniae or Moraxella catarrhalis could be observed in gram-stained sputum obtained just after the first administration of an antimicrobial agent. Case 1 was a 53-year-old man with pneumonia caused by gram-positive diplococcus, identified as S. pneumoniae, who was administered 2 g of ampicillin over a period of 1 h. Gram-stained sputum showed smaller or gram-negative pneumococci at the completion of administration of the agent, a decreased number of cocci at 1 h after administration, and almost no cocci at 12 h after the completion of administration. Case 2 was a 72-year-old woman with pneumonia caused by diplococcus, identified as S. pneumoniae, who was administered 2 g of ampicillin over a period of 1 h. Gram-stained sputum showed weakly stained, small cocci at the completion of administration of the agent and few cocci at 1 h after the completion of administration. Case 3 was a 58-year-old woman with pneumonia caused by a gram-negative diplococcus, identified as Moraxella catarrhalis, who was administered 1 g of cefotaxime over a period of 30 min. Gram-stained sputum showed few extracellular cocci and some intracellular cocci inside neutrophils 1 h after administration and no cocci 2 h after the completion of administration. These three cases showed that gram-stained sputum obtained just after and/or 1 h after administration of the first antimicrobial agent were suitable as the quickest therapeutic indicator of the effectiveness of empiric therapy, with the effectiveness of the agent being shown much earlier than with markers such as the white blood cell count and C-reactive protein level. PMID:23073648
Abstract in portuguese Objetivou-se com este trabalho estudar a etiologia da mastite em ovelhas na região nordeste do Pará, além de estabelecer o perfil de sensibilidade das bactérias isoladas frente a antimicrobianos. Foram examinadas 176 ovelhas da raça Santa Inês, em lactação, mantidas em sistema semi-intensivo, pertencentes a sete propriedades especializadas na criação de ovinos. Foi realizado o exame clínico da glândula mamária, o exame macroscópico da secreção láctea por (more) meio do Teste da Caneca Telada, o California Mastitis Test (CMT), o exame microbiológico do leite e o antibiograma. Das 352 metades mamárias estudadas (176 ovelhas), 21 (5,97%) apresentaram mastite clínica, 26 (7,39%) apresentaram mastite subclínica e 305 (86,64%) metades mamárias foram negativas. A maioria dos animais acometidos pela mastite estava no terço médio da lactação, com menor número de crias e maior número de lactações. Na mastite clínica (MC) as bactérias isoladas foram Staphylococcus spp. coagulase negativo (42,9%); Staphylococcus aureus (9,52%); Streptococcus spp. (4,76%) e Escherichia coli (4,76%). As associações observadas foram Staphylococcus aureus e Streptococcus spp. (4,76%); Staphylococcus spp. coagulase negativo não hemolítica, Staphylococcus spp. coagulase negativo hemolítica e Staphylococcus spp. coagulase negativo pigmento não hemolítica (4,76%). Já na mastite subclínica (MSC), as bactérias isoladas foram Staphylococcus spp. coagulase negativo (26,9%); Staphylococcus aureus (15,4%); Streptococcus spp. (7,69%); Escherichia coli (7,69%) e Citrobacter freundii (11,5%). A associação observada foi Staphylococcus spp. coagulase negativo não hemolítica e Staphylococcus spp. coagulase negativo hemolítica (3,85%). Os antimicrobianos com maior eficácia contra os agentes isolados Gram positivos foram penicilina/novobiocina (100%), cefalotina (100%) e florfenicol (100%) e contra o Citrobacter freundii foram a ampicilina (100%) e florfenicol (100%). Já em relação a Escherichia coli, 66,7% dos isolados mostraram-se resistentes à ampicilina, cefalotina, florfenicol e tetraciclina. A mastite está presente em ovelhas no estado do Pará, havendo a necessidade de estimar, em estudos futuros, as perdas econômicas causadas por essa enfermidade. O CMT apresentou resultados satisfatórios, podendo ser recomendado como teste de triagem para o diagnóstico de casos individuais de mastite subclínica em ovinos, uma vez que apresentou boa relação com o exame microbiológico. No antibiograma foi observado que a maioria dos agentes isolados apresenta-se sensível aos diferentes antimicrobianos testados, sendo os antibióticos com melhor eficiência o florfenicol e a cefoxitina. Abstract in english The objective of this paper was to study the etiology of mastitis in sheep at northeastern Pará, and to establish the sensitivity of isolated bacteria to antibiotics. A total of 176 Santa Inês nursing sheep kept in semi-intensive system from seven properties were examined. The mammary gland was clinically examined and the milk was submitted to the Caneca Telada Test, the California Mastitis Test (CMT), bacteriological examinations and antibiograms. Out of the 352 mammar (more) y halves (176 sheep), 5.9% (21/352) had clinical mastitis and by the CMT test, 7.39% (26/352) had subclinical mastitis and 86.64% (305/352) mammary halves did not have mastitis. Most of the animals with mastitis were in the second third of the lactation period, had less kids and more lactation periods. The following bacteria were isolated from the clinical mastitis Staphylococcus spp. coagulase negative (42,9%); Staphylococcus aureus (9.52%); Streptococcus spp. (4.76%) and Escherichia coli (4.76%). Were observed associations of Staphylococcus aureus and Streptococcus spp. (4,76%); Staphylococcus spp. coagulase negative nonhemolytic, Staphylococcus spp. coagulase negative hemolytic and Staphylococcus spp. coagulase negative non hemolytic pigment (4.76%). Already in subclinical mastitis the bacteria isolated were Staphylococcus spp. coagulase negative (26.9%); Staphylococcus aureus (15.,4%); Streptococcus spp. (7.69%); Escherichia coli (7.69%) and Citrobacter freundii (11.5%). Were observed associations of Staphylococcus spp. coagulase negative nonhemolytic and Staphylococcus spp. coagulase negative hemolytic (3.85%). The most efficient antibiotics for the Gram positive agents were penicile/novobiocine (100%), cefalotine (100%) and florfenicol (100%) and for the Citrobacter freundii were ampicilina (100%) and florfenicol (100%). In relation to Escherichia coli, 66.7% of isolates to ampicillin, cephalothin, florfenicol and tetracycline were resistant. Mastitis is present in sheep in the State of Pará, and it's necessary to estimate, in future studies, the economic losses caused by this disease. The CMT show satisfactory results and can be recommended as a screening test for diagnosing individual cases of subclinical mastitis in sheep, once had a good relationship with the microbiological examination. In the antibiogram where most of the isolated agents appear sensitive to different antibiotics tested, the antibiotics with the best efficiency were florfenicol and cefoxitin.
Abstract in spanish La neumonía adquirida en la comunidad (NAC) continúa siendo una condición de alta prevalencia y potencialmente letal. El Streptococcus pneumoniae, es el agente etiológico más frecuente de las NAC. El objetivo del presente estudio, es describir las características clínicas y demográficas, así como también la evolución, de los pacientes adultos ingresados por NAC al servicio de medicina del Hospital San Juan de Dios. Nosotros estudiamos en forma retrospectiva a 2 (more) 00 pacientes adultos ingresados con diagnóstico de NAC. Se confirmó el diagnóstico en 170 de ellos. El promedio de edad fue de 68 años. La vacunación antiinfluenza en mayores de 65 años fue de 51%. De la comorbilidad no respiratoria, la hipertensión arterial y la diabetes mellitus, fueron las más prevalentes (59% y 31% respectivamente), Neumonía en adultos. Campaña invierno 2003 - K. Dintrans A. et al. seguidas por la insuficiencia cardíaca (22%). La comorbilidad respiratoria más frecuente fue la enfermedad pulmonar obstructiva crónica (EPOC): 19%. El esquema antibiótico de elección fue una cefalosporina de tercera generación asociada a un macrólido. La terapia secuencial se realizó en 140 pacientes (82%), empleándose una fluoroquinolona antineumocócica en 90% de los casos. La mediana de los días de hospitalización fue de 6 días. Un 40% de los pacientes requirió traslado a una unidad de mayor complejidad. La letalidad asociada a los pacientes con diagnóstico confirmado de NAC, llegó al 11%. En solo un paciente se aisló un Streptococcus pneumoniae resistente a la penicilina en los hemocultivos. Conclusión: La NAC es una entidad prevalente especialmente en pacientes adultos mayores, con características clínicas y demográficas específicas, cuya mortalidad y curso clínico se pueden conocer y modificar Abstract in english Community acquired pneumonia (CAP) continues being a condition of high prevalence, and potentially lethal. Streptococcus pneumoniae is the most frequent etiological agent of CAP. The objective of the present study is to describe the clinical and demographic characteristics, as well as the evolution, of adult patients admitted with CAP to the service of medicine of a Santiago general hospital (Hospital San Juan de Dios). 200 adults admitted with CAP diagnosis during winter (more) 2003, were retrospectively studied. In 170 out of these 200 patients, diagnosis was confirmed. In average the patients were 68 years old. 51% of patients older than 65 y.o. had received influenza vaccination. High blood pressure, diabetes mellitus and heart failure were the most prevalent non respiratory comorbidities (59, 31 and 22% respectively). Chronic obstructive pulmonary disease was the most prevalent respiratory comorbidity (19%). The antibiotic therapy by election was a third generation cephalosporin, associated with a macrolide. The switch therapy was done in 140 patients (82%), using an antipneumococcal fluoroquinolone in 90% of the cases. The median period of hospitalization was 6 days. 40% of the patients required to be transferred to a clinical unit of higher complexity. In patients having a confirmed diagnosis of community acquired pneumonia lethality rose up to 11%. In only one of the patients, a Streptococcus pneumoniae resistant to Penicillin was isolated in the blood culture. Conclusion: CAP is a prevalent disease, especially in elderly patients, with specific clinical and demographic characteristics. CAP`s evolution and mortality rate can be known and modified
Abstract in portuguese Nos últimos anos tem sido descrita, no mundo ocidental, uma redução da incidência da pneumonia aguda da comunidade (PAC) nas crianças, parodoxalmente associada a maior gravidade dos casos internados. O presente estudo pretendeu caracterizar os casos de PAC internados e compará-los com um estudo anterior a 2001. Recolhemos dados referentes a 63 internamentos, durante seis meses. Houve predomínio do grupo dos 0-2 anos. Na radiografia torácica, em 58 casos (92,1%) de (more) tectou-se condensação/atelectasia e em 17 (27,0%) derrame pleural (DP). Onze dos DP corresponderam a empiema (17,4% dos internamentos). Isolou-se agente bacteriano em cinco casos: Streptococcus pyogenes (dois, líquido pleural), Streptococcus pneumoniae (dois, hemocultura) e Haemophilus influenzae (um, hemocultura). Foi prescrita antibioticoterapia em 61 (96,8%) crianças. A duração mediana de internamento foi de cinco dias. Constatou-se, nos casos de DP, idade superior, maior duração de febre, proteína C reactiva mais alta e maior duração de internamento e de antibioticoterapia endovenosa. Comparativamente com o estudo anterior, constatou-se haver maior gravidade dos casos internados, traduzida por maior incidência de DP e empiema; paradoxalmente, registou-se menor duração da febre em meio hospitalar e menor duração do internamento. No estudo actual houve menor prescrição antibiótica prévia à admissão e maior prescrição de ampicilina durante o internamento. Na literatura, a maior gravidade das pneumonias internadas nos últimos anos tem sido associada à emergência de serotipos mais agressivos de Stretococcus pneumoniae não integrados na vacina heptavalente, assumindo interesse crescente a introdução de vacinas que os incluam. As pneumonias complicadas devem ser orientadas para centros de referência com experiência no seu diagnóstico e tratamento. Abstract in english The past few years have seen a decline in community acquired pneumonia (CAP) in children in the western world, although this has gone hand-in-hand with more serious cases needing hospital admission. Our study characterises cases of CAP admitted to hospital and compares this data with a 2001 study. We collected data on 63 admissions over a six-month period. The majority were aged 0-2 years old. Chest X-ray showed consolidation/atelectasy in 58 (92.1%) and pleural effusion (more) (PE) in 17 (27.0%), of which 11 were empyema (17.4% of all admissions). The bacterial agent was isolated in five cases: Streptococcus pyogenes (two, pleural fluid), Streptococcus pneumoniae (two, blood culture) and Haemophilus influenzae (one, blood culture). Sixty-one children (96.8%) were prescribed antibiotherapy. The median length of hospital stay was five days. Patients with PE were older, had a longer course of fever, higher inflammatory parameters, longer hospital stay and longer course of iv antibiotics. Compared to the prior study we found greater severity of CAP, with higher prevalence of PE and empyema. Nevertheless there was a shorter course of fever during hospital stay and shorter hospital stay. We also noticed less antibiotic prescription prior to admission and greater prescription of ampicillin during hospital stay. In the literature, the higher severity of CAP has been partially attributed to the emergence of more aggressive serotypes of Stretococcus pneumoniae not included in the heptavalent vaccine. There is therefore a greater interest in new vaccines containing them. Complicated CAP should be referred to centres specialising in its diagnosis and management.
Abstract in portuguese Introdução: Os derrames pleurais podem complicar as pneumonias na população pediátrica. Assumem especial importância pelas implicações na duração do internamento, geralmente prolongado, e pela morbilidade associada. Objectivos: Caracterizar uma população de doentes com pneumonia complicada de derrame; determinar os possíveis factores de prognóstico a partir de dados clínicos, radiológicos e analíticos na admissão; e avaliar a influência das intervençõ (more) es terapêuticas na evolução da doença. Métodos: Revisão casuística dos doentes com idade inferior a 18 anos e derrame pleural parapneumónico, internados de Julho de 1997 a Junho de 2004 (7 anos). Resultados: Foram estudados 118 casos, 60% do sexo masculino, com idade média 7 anos. A incidência de derrame pleural aumentou ao longo do período do estudo. Verificou-se maior incidência de casos no Outono e no Inverno. Na admissão, 60% dos doentes apresentavam sinais de dificuldade respiratória e 39% dor torácica. Em 40% dos doentes foram detectados septos pleurais na admissão, o que se associou a maior duração de internamento e de antibioticoterapia e mais frequente necessidade de cirurgia. Em 72% dos doentes foi efectuada toracocentese (pH médio: 7,24). Em 17% foi possível isolar o agente: Streptococcus pneumoniae (cinco), Staphylococcus aureus (quatro) e Streptococcus pyogenes (quatro). Foram submetidos a drenagem pleural 52% e necessitaram de cirurgia 18%. A mediana da duração de internamento foi de 15 dias e a média de 16,4 dias (2 a 51). Discussão: Associam-se a pior prognóstico a presença de: sinais de dificuldade respiratória; septos; empiema; baixo valor no líquido pleural de pH, glicose ou proteínas; desidrogenase láctica elevada no líquido pleural e proteína C-reactiva sanguínea aumentada. A drenagem pleural e/ou cirurgia mais precoces provavelmente diminuem o tempo de doença e de internamento. Conclusão: Os derrames parapneumónicos complicados são tratados com êxito em centros de referência com experiência nos diferentes tipos de intervenção que poderão ser necessários. Abstract in english Introduction: Pleural effusions can complicate pneumonias in children and adolescents and are usually associated with a long hospital stay and increased morbidity. Aims: To characterise a population of patients with parapneumonic pleural effusion and to establish possible prognostic factors on admission based on clinical, imaging and analytical data. To correlate treatment options with the outcome. Methods: Case review of patients under 18 years old with parapneumonic ple (more) ural effusion, admitted between July 1997 - June 2004 (7 years). Results: 118 patients were included, 60% male, with mean age 7 years. The incidence of pleural effusion increased throughout the period of the study. The admissions occurred predominantly in autumn and winter. On admission 60% of patients had respiratory distress and 39% chest pain. In 40% loculations were found on admission and were associated with longer hospital stay, longer course of antibiotic therapy and more frequent need for surgery. Thoracentesis was performed in 72% of patients (mean pH pleural fluid 7.24). The aetiologic agent was identified in 17% of cases: Streptococcus pneumoniae (five), Staphylococcus aureus (four) and Streptococcus pyogenes (four). In our study, 52% of patients underwent pleural drainage and 18% surgery. Median length of hospital stay was 15 days with mean 16.4 days (2 - 51). Discussion: Factors associated with worse prognosis were respiratory distress, loculations, empyema, low pH in pleural fluid, glucose or proteins in pleural fluid, high lactic dehydrogenase level in pleural fluid and high serum C-reactive protein. Pleural drainage and/or surgery can shorten hospital stay and improve outcome. Conclusion: Complicated parapneumonic pleural effusions are managed successfully in centres with experience in the different types of procedure that might be necessary.
Assessment of an extraction protocol to detect the major mastitis-causing pathogens in bovine milk.
Despite all efforts to control its spread, mastitis remains the most costly disease for dairy farmers worldwide. One key component of better control of this disease is identification of the causative bacterial agent during udder infections in cows. Mastitis is complex, however, given the diversity of pathogens that must be identified. Development of a rapid and efficient bacterial species identification tool is thus necessary. This study was conducted to demonstrate the feasibility of bacterial DNA extraction for the automated molecular detection of major mastitis-causing pathogens directly in milk samples to complement traditional microbiological identification. Extraction and detection procedures were designed and optimized to achieve detection in a respectable time frame, at a reasonable cost, and with a high throughput capacity. The following species were identified: Staphylococcus aureus, Escherichia coli, Streptococcus uberis, Streptococcus agalactiae, Streptococcus dysgalactiae, and Klebsiella spp. (including Klebsiella oxytoca and Klebsiella pneumoniae). The detection procedure includes specific genomic DNA amplification by multiplex PCR for each species, separation by capillary electrophoresis, and laser-assisted automated detection. The specificity of the primers was assessed with a panel of bacteria representing mastitis-negative control species. The extraction protocol comprised multiple steps, starting with centrifugation for fat removal, followed by heating in the presence of a cation exchange resin to trap divalent ions. The analytical sensitivity was 100 cfu/mL for milk samples spiked with Staph. aureus, Strep. dysgalactiae, and E. coli, with a tendency for K. pneumoniae. The detection limit was 500 cfu/mL for Strep. uberis and Strep. agalactiae. The overall diagnostic sensitivity (95.4%) and specificity (97.3%) were determined in a double-blind randomized assay by processing 172 clinical milk samples with microbiological characterization as the gold standard. When the physical nature of the milk samples was too altered, DNA purification with a magnetic bead-based system was used. Of the apparent false-positive samples, 5 were identified by specific microbiological analysis as true-positive Staph. aureus co-infections, with further confirmation by ribosomal 16S sequencing. The proposed methodology could, therefore, become an interesting tool for automated PCR detection of major mastitis pathogens in dairy cattle. PMID:21524507
Abstract in portuguese O presente estudo investigou o uso da cito-(73,0%), Arcanobacterium pyogenes (6,0%), Streptococlogia aspirativa com agulha fina no diagnóstico da lin-cus spp. ? hemolítico (5,0%) e Escherichia coli (4,0%) fadenite em ovinos e a ocorrência de microrganismos foram os microrganismos mais frequentes nos animais nos linfonodos com lesões, com ênfase no isolamento de com linfadenite. Streptococcus spp. (21,0%) e Staphylo-Corynebacterium pseudotuberculosis. Foram utili (more) zados coccus spp. (7,0%) foram as bactérias isoladas com 100 linfonodos de ovinos com aumento de volume su-maior frequência nos linfonodos sem lesões colhidos em gestivos de linfadenite e 100 linfonodos de ovinos sem abatedouro. A punção aspirativa com agulha fina perlesões, colhidos em abatedouro. C. pseudotuberculosis mitiu identificar microrganismos "corineformes" em 79 (79,0%) animais com linfadenite e, destes, 73 (73,0%) foram identificados como C. pseudotuberculosis. Nenhuma linhagem de C. pseudotuberculosis foi isolada dos linfonodos dos animais sem lesões. Concluiu-se que C. pseudotuberculosis foi o microrganismo mais freqüente nos ovinos com linfadenite, e que a citologia aspirativa pode ser utilizada como método de triagem no diagnóstico da linfadenite caseosa ovina Abstract in english The fine needle aspiration in diagnosis of lymphadenitis in sheep, and occurrence of microorganisms in the lymph nodes, with emphasis to identification of Corynebacterium pseudotuberculosis were investigated. One hundred sheep with lymphadenitis and 100 lymph nodes without lesions collected from sheep in slaughterhouses were evaluated. C. pseudotuberculosis (73.0%), Arcanobacterium pyogenes (6.0%), Streptococcus spp. ? hemolytic (5.0) and Escherichia coli (4.0%) were (more) the more frequent causal agents in sheep with lymphadenitis. Streptococcus spp. (21.0%) and Staphylococcus spp. (7.0%) were the more common microorganisms identified in lymph nodes without lesions sampled in slaughterhouse. Fine needle aspiration enable identify 79 (79.0%) microorganisms with "corynebacteria" aspect in sheep with lymphadenitis. From these, 73 (73.0%) were identified as C. pseudotuberculosis. None strain of C. pseudotuberculosis was isolated from lymph nodes of animals without lesions. The results showed the high frequency of C. pseudotuberculosis in sheep with lymphadenitis, and possibility the use of fine needle aspiration in initial diagnosis of lymphadenitis in sheep
Abstract in spanish Objetivo Estimar el impacto de la enfermedad por Streptococcus pneumoniae en la población mayor de 60 años en Bogotá D.C. Colombia. Métodos Se realizó un estudio de impacto de enfermedad por neumococo combinando una búsqueda sistemática de literatura con el análisis de fuentes de datos rutinarios de mortalidad, consultas y hospitalizaciones debidas neumonías y meningitis en adultos mayores de 60 años. Resultados Se estimó para 2008 en la población bogotana may (more) or de 60 años la ocurrencia de 6 585 neumonías por todos los agentes, 689 debidas a Streptococcus pneumoniae, y 73 meningitis, 12 producidas por neumococo. El total de muertes por neumonías se estimó en 1 910, 82 atribuibles al neumococo, y de las 40 muertes por meningitis, 7 habrían ocurrido en casos de meningitis neumocócicas. Conclusiones El impacto de la enfermedad debida a neumococo en población mayor de 60 años en Bogotá justifica la consideración de estrategias específicas de prevención tales como la vacunación. Abstract in english Objective Estimating the impact of pneumococcal disease amongst adults living in Bogota, Colombia Methods The impact of pneumococcal disease was studied by combining a systematic literature search with analysing routine sources regarding mortality, consultation and hospitalisation dates due to pneumonia and meningitis. Results The occurrence of 6,585 cases of pneumonia by all germs was estimated for 2008 in the adult population aged over 60, 689 cases being due to Strepto (more) coccus pneumonia, and 73 cases of meningitis, plus 12 cases caused by pneumococcus. The total of deaths from pneumonia was estimated to be 1,910 cases (82 due to pneumonia) and 40 deaths occurred from meningitis (7 of these cases being due to pneumococcal meningitis). Conclusiones The impact of pneumococcal disease in adults aged over 60 in Bogota (only taking into account cases of meningitis and pneumonia with blood and CSF isolates) justifies considering specific prevention strategies such as vaccination.
Abstract in portuguese A presença de formigas (Hymenoptera: Formicidae) em ambientes hospitalares pode constituir um problema de saúde pública, especialmente por serem vetores mecânicos de organismos patogênicos. O trabalho teve como objetivo realizar o levantamento de formigas e analisar a presença de bactérias a elas associadas em dois hospitais regionais de médio porte da cidade de Divinópolis, MG. As coletas foram realizadas mensalmente, durante um período de seis meses. Foram col (more) etadas formigas Pheidole sp1 e sp2, Linepithema humile, Wasmannia auropunctata, Camponotus sp1 e sp2, Odontomachus sp, Solenopsis sp, Acromyrmex sp e Tapinoma melenocephalum. Observou-se que estas transportavam mecanicamente Pseudomonas aeruginosa, Enterococcus, Streptococcus, Staphylococcus patogênico e não patogênico e Escherichia coli. Tais resultados evidenciam a propensão à ocorrência de infecções hospitalares nesses locais pela transmissão mecânica de agentes patogênicos por formigas. Abstract in english The presence of ants (Hymenoptera: Formicidae) in hospital environments may constitute a public health problem, especially since they are mechanical vectors for pathogenic organisms. This study aimed to survey the ant populations and analyze the presence of bacteria associated with them in two medium-sized regional hospitals in the municipality of Divinópolis, Minas Gerais, Brazil. Specimens were collected every monthly over a six-month period. The following ant species (more) were found: Pheidole sp1 and sp2, Linepithema humile, Wasmannia auropunctata, Camponotus sp1 and sp2, Odontomachus sp, Solenopsis sp, Acromyrmex sp and Tapinoma melenocephalum. It was observed that these ants mechanically transported Pseudomonas aeruginosa, Enterococcus, Streptococcus, Escherichia coli and non-pathogenic and pathogenic Staphylococcus. These results show the propensity for occurrences of hospital infections at these sites caused by mechanical transmission of pathogens by ants.
Fermentation, fractionation and purification of streptokinase by chemical reduction method.
BACKGROUND AND OBJECTIVES : Streptokinase is used clinically as an intravenous thrombolytic agent for the treatment of acute myocardial infarction and is commonly prepared from cultures of Streptococcus equisimilis strain H46A. The objective of the present study was the production of streptokinase from strain H46A and purification by chemical reduction method. MATERIALS AND METHODS : The rate of streptokinase production evaluated under the effect of changes on some fermentation factors. Moreover, due to the specific structure of streptokinase, a chemical reduction method employed for the purification of streptokinase from the fermentation broth. The H46A strain of group C streptococcus, was grown in a fermentor. The proper pH adjusted with NaOH under glucose feeding in an optimum temperature. The supernatant of the fermentation product was sterilized by filtration and concentrated by ultrafiltration. The pH of the concentrate was adjusted, cooled, and precipitated by methanol. Protein solution was reduced with dithiothreitol (DTT). Impurities settled down by aldrithiol-2 and the biological activity of supernatant containing streptokinase was determined. RESULTS : In the fed -batch culture, the rate of streptokinase production increased over two times as compared with the batch culture and the impurities were effectively separated from streptokinase by reduction method. CONCLUSION : Improvements in SK production are due to a decrease in lag phase period and increase in the growth rate of logarithmic phase. The methods of purification often result in unacceptable losses of streptokinase, but the chemical reduction method give high yield of streptokinase and is easy to perform it. PMID:22347582
Abstract in spanish Los estreptococos de grupo milleri se caracterizan por su tendencia a provocar infecciones piógenas invasoras en diferentes localizaciones. Las meningitis estreptocócicas no neumocócicas son poco frecuentes en pacientes adultos y pueden asociarse a la presencia de un absceso cerebral. Los abscesos cerebrales son colecciones localizadas dentro del parénquima cerebral que se originan como complicación de una infección, siendo los estreptococos microaerófilos y las ba (more) cterias anaerobias los microorganismos más frecuentemente aislados. Aunque no es inusual la presencia de colecciones intracraneales de etiología infecciosa en pacientes con infección por VIH-1, los abscesos cerebrales producidos por las bacterias piógenas habituales son muy infrecuentes y es T. gondii el agente etiológico más frecuente. Aportamos un caso de meningitis y absceso cerebral por S. intermedius en un paciente con infección por VIH-1. Abstract in english Streptococcus milleri group have been recognized as an important pathogens for abscess formation in various organs. Streptococci other than Streptococcus pneumoniae are a rare cause of bacterial meningitis in adults and can be associated with the presence of an undiagnosed brain abscess. Brain abscess is a focal collection within the brain parenchyma wich can arise as a complication of a variety of infections. The most common etiologic organisms in clinical series have be (more) en microaerophilic streptococci and anaerobic bacterias. Although intracraneal mass lesions that occur as a result of infection have commonly been reported in patients infected with the human immunodeficiency virus, brain abscess due to the common bacterial pathogens are rarely described in HIV infected patients and Toxoplasma gondii is the organism most frecuently isolated from stereotactic brain biopsy in these patients. We report a patient with both HIV-1 infection and streptococcal meningitis secondary to brain abscess caused by S. intermedius
Transcription of clpP is enhanced by a unique tandem repeat sequence in Streptococcus mutans.
Streptococcus mutans, the primary causative agent of human dental caries, contains a single copy of the gene encoding ClpP, the chief intracellular protease responsible for tolerance to various environmental stresses. To better understand the role of ClpP in stress response, we investigated the regulation of clpP expression in S. mutans. Using semiquantitative reverse transcription-PCR analysis, we observed that, under nonstressed conditions, clpP expression is somewhat constant throughout the growth phases, although it gradually decreases as cells enter the late stationary phase. The half-life of the clpP transcript was found to be less than 1 minute. Sequence analysis of the clpP locus reveals the presence of a 50-bp tandem repeat sequence located immediately upstream of the clpP promoter (PclpP). PCR and DNA sequence analyses suggest that the number of tandem repeat units can vary from as few as two to as many as nine, depending on the particular S. mutans isolate. Further analysis, using a transcriptional reporter fusion consisting of PclpP fused to a promoterless gusA gene, indicates that the presence of the repeat sequence region within PclpP results in an approximately fivefold increase in expression from PclpP compared to the repeat-free transcriptional reporter fusion. CtsR, a transcriptional repressor that negatively regulates clpP expression, has no effect on this repeat-mediated induction of clpP transcription. Furthermore, the repeat sequence is not necessary for the induction of clpP under stress conditions. Database searches indicate that the region containing the tandem repeats is absent in the clpP loci in other bacteria, including other closely related Streptococcus spp., suggesting that the repeat sequences are specific for the induction of clpP expression in S. mutans. We speculate that a host-specific transcriptional activator might be involved in the upregulation of clpP expression in S. mutans. PMID:19047352
Regulation of gbpC expression in Streptococcus mutans.
Streptococcus mutans, the principal causative agent of dental caries, produces four glucan-binding proteins (Gbp) that play major roles in bacterial adherence and pathogenesis. One of these proteins, GbpC, is an important cell surface protein involved in biofilm formation. GbpC is also important for cariogenesis, bacteremia, and infective endocarditis. In this study, we examined the regulation of gbpC expression in S. mutans strain UA159. We found that gbpC expression attains the maximum level at mid-exponential growth phase, and the half-life of the transcript is less than 2 min. Expression from PgbpC was measured using a PgbpC-gusA transcriptional fusion reporter and was analyzed under various stress conditions, including thermal, osmotic, and acid stresses. Expression of gbpC is induced under conditions of thermal stress but is repressed during growth at low pH, whereas osmotic stress had no effect on expression from PgbpC. The results from the expression analyses were further confirmed using semiquantitative reverse transcription-PCR analysis. Our results also reveal that CovR, a global response regulator in many Streptococcus spp., represses gbpC expression at the transcriptional level. We demonstrated that purified CovR protein binds directly to the promoter region of PgbpC to repress gbpC expression. Using a DNase I protection assay, we showed that CovR binds to DNA sequences surrounding PgbpC from bases -68 to 28 (where base 1 is the start of transcription). In summary, our results indicate that various stress conditions modulate the expression of gbpC and that CovR negatively regulates the expression of the gbpC gene by directly binding to the promoter region. PMID:17616585
Vaccines against bovine mastitis in the New Zealand context: what is the best way forward?
Mastitis is an important animal health disease which constitutes a serious problem for the dairy industry in New Zealand. Mastitis reduces milk yield and quality, necessitates the use of antibiotic therapy, with associated risks of contaminating the raw milk supply, and imposes a serious economic burden, currently estimated at NZ$300 million per year. Mastitis is caused by a variety of infectious agents. In the New Zealand context, with cattle grazing on pasture, Streptococcus uberis is a major bacterial pathogen, responsible for a significant proportion of clinical cases, especially during early lactation and the dry period. Other pathogens of significance include Staphylococcus aureus, Streptococcus dysgalactiae and Escherichia coli, as well as so-called 'minor pathogens', namely coagulase-negative staphylococci(CNS). Current strategies aimed at reducing cases of mastitis include improved hygiene in the farm environment, particularly with regards to the health and cleanliness of teats. Once mastitis occurs, antibiotic therapy is a favoured option, and as a prophylactic tool, in the form of dry-cow therapy, has also shown value. Prevention of mastitis using immunological tools such as vaccines lags behind the major vaccine breakthroughs that have been achieved in preventing and/or reducing the severity of numerous infectious diseases in animals. In this review, the current state of research in the area of development of vaccines against mastitis is summarised, with particular emphasis on bacteria important to the dairy farming industry in New Zealand. Few, if any, effective vaccines have been designed to prevent or mitigate intramammary infections. It is argued that novel approaches must be considered to search for vaccine candidates, and vaccines need to be designed and constructed within the special framework of their uses, in the mammary gland which offers a unique immunological environment. In addition, effective vaccines against mastitis due to Strep. uberis may be more likely to emerge from strategies that target the cell-mediated arm of the immune response rather than strategies that target specific antibody responses. PMID:19521461
The LEADER program monitors the in vitro activity of linezolid and comparator agents across the United States using reference broth microdilution and supportive molecular susceptibility-based investigations. This report summarizes the data from the 2010 program, the seventh consecutive year. A total of 61 medical centers from the USA including 7 medical centers specializing in children's healthcare provided a total of 6801 Gram-positive pathogens. The medical centers represented all 9 US Bureau of Census geographic regions. The organisms tested by reference broth microdilution were 3105 Staphylococcus aureus, 944 coagulase-negative staphylococci (CoNS), 934 Enterococci, 803 Streptococcus pneumoniae, 604 ?-haemolytic streptococci, and 411 viridans group and other streptococci. The MIC(90) value for each of the above 6 targeted groups of organisms was 1 ?g/mL. The "all organism" linezolid-resistant and nonsusceptible rate was 0.38%, which has been constant at 0.34% (2009) to 0.45% (2006) for the last 4 years. For Staphylococcus aureus, only 0.06% of the isolates were linezolid-resistant (MIC, ?8 ?g/mL); however, 2 additional methicillin-resistant Staphylococcus aureus had a cfr and a MIC of only 4 ?g/mL. Resistance to linezolid was detected in 7 enterococci (0.75%) and 14 CoNS isolates (1.48%). This also represents a stable rate of resistance noted since the 2006 LEADER program report. Of note, for the first time in the 7 years of the Leader Program a linezolid-resistant Streptococcus pneumoniae was encountered. Overall, the results of the LEADER program demonstrate that linezolid maintains excellent in vitro activity against target Gram-positive pathogens across the USA. The LEADER program continues to provide valuable reference and molecular-level monitoring of linezolid activity. PMID:22704791
Abstract in portuguese Não existem dados definitivos e consistentes sobre a real distribuição dos microorganismos presentes em pacientes com Rinossinusite Crônica (RSC). A variabilidade dos resultados de estudos em RSC deve-se às diferentes técnicas utilizadas como método de coleta, variações nos métodos de cultura, uso prévio de antibiótico, dificuldade de se distinguir agentes colonizadores e patogênicos. FORMA DE ESTUDO: Clínico-prospectivo. OBJETIVO: Estudar a incidência dos (more) microrganismos presentes nos pacientes com RSC na nossa região, através da cultura da secreção do seio maxilar, coletada sob visão endoscópica. MATERIAIS E MÉTODOS: Estudo transversal em 62 pacientes com RSC, submetidos à coleta de secreção de seio maxilar por via endoscópica, com material enviado para cultura para diagnóstico microbiológico. RESULTADOS: Das 62 amostras estudadas, em 33 (53,2%) não houve crescimento de microrganismos; 29 (45,2%) apresentaram isolamento de aeróbios; um caso (1,6%) mostrou crescimento de fungo; não houve o isolamento de microrganismos anaeróbios. Pseudomonas aeruginosa foi isolada com maior frequência - em 8 amostras (27,6%), Staphylococcus aureus e Staphylococcus epidermidis em 4 amostras cada um (13,9%), Streptococcus pneumoniae em 3 amostras (10,4%), outros Gram-negativos em 17 amostras (31%). CONCLUSÃO: Pseudomonas aeruginosa, outras bactérias Gram-negativas e Staphylococcus spp constituíram a microbiota predominante nos seios paranasais de pacientes com RSC. Abstract in english There isn't definitive and consistent data concerning the distribution of bacterial species in patients with Chronic Sinusitis (CS). The variability of the results from studies in CS may be due to the different techniques used as collection method, variations in culture methods, previous antibiotic use, and difficulty in distinguishing bacterial flora from pathogenic agents. STUDY DESIGN: Clinical prospective. AIM: To identify the incidence of microorganisms in patients w (more) ith CRS by growing bacteria from the secretion of the maxillary sinus. PATIENTS AND METHODS: Cross-sectional study in 62 patients that had undergone FESS for treatment of chronic sinusitis; cultures from the maxillary sinus were obtained. RESULTS: 62 samples, 33 (53.2%) had no growth; 29 (45.2%) counts of aerobic bacteria; one case (1.6%) of fungus growth; we did not find anaerobic bacteria. Pseudomonas aeruginosa was the one more frequently found - 8 samples (27.6%), Staphylococcus aureus and Staphylococcus epidermidis in 4 samples each; Streptococcus pneumoniae in 3 samples (10.4%); other Gram negative agents in 17 samples (31%). CONCLUSION: In the present study we concluded that Pseudomonas aeruginosa, other Gram negatives bacteria and Staphylococcus spp were the representatives of the bacterial flora found in the paranasal sinuses of patients with CS.
Repertoire of intensive care unit pneumonia microbiota.
Despite the considerable number of studies reported to date, the causative agents of pneumonia are not completely identified. We comprehensively applied modern and traditional laboratory diagnostic techniques to identify microbiota in patients who were admitted to or developed pneumonia in intensive care units (ICUs). During a three-year period, we tested the bronchoalveolar lavage (BAL) of patients with ventilator-associated pneumonia, community-acquired pneumonia, non-ventilator ICU pneumonia and aspiration pneumonia, and compared the results with those from patients without pneumonia (controls). Samples were tested by amplification of 16S rDNA, 18S rDNA genes followed by cloning and sequencing and by PCR to target specific pathogens. We also included culture, amoeba co-culture, detection of antibodies to selected agents and urinary antigen tests. Based on molecular testing, we identified a wide repertoire of 160 bacterial species of which 73 have not been previously reported in pneumonia. Moreover, we found 37 putative new bacterial phylotypes with a 16S rDNA gene divergence ? 98% from known phylotypes. We also identified 24 fungal species of which 6 have not been previously reported in pneumonia and 7 viruses. Patients can present up to 16 different microorganisms in a single BAL (mean ± SD; 3.77 ± 2.93). Some pathogens considered to be typical for ICU pneumonia such as Pseudomonas aeruginosa and Streptococcus species can be detected as commonly in controls as in pneumonia patients which strikingly highlights the existence of a core pulmonary microbiota. Differences in the microbiota of different forms of pneumonia were documented. PMID:22389704
[Role of infectious agents in the emergence of malignant tumors].
According to the data of the International Agency for Research on Cancer (IARC), at least 6 virus species (HPV, EBV, HHV-8/KSHV, HTLV-1, HBV, HCV), 4 helminthes species (Schistosoma haematobium and japonicum, Opisthorchis viverrini, Clonorchis sinensis) and I bacterium species (Helicobacter pylori) have been proved to be capable of causing the development of cancer. The analysis of the data available shows that Merkel cell polyomavirus (MCV), herpes simplex virus (HSV), John Cunningham polyomavirus (JCV), monkey virus 40 (SV40), cytomegalovirus (CMV), xenotropic murine leukemia virus (XMRV), Helicobacter bilis and hepaticus, Campylobacter jejuni, Fusobacterium varium, enteropathogenic Escherichia coli, enterotoxigenic Bacteroides fragilis, Bacteroides vulgatus, Prevotella spp., Streptococcus bovis and anginosus, Treponema denticola, Salmonella typhi, paratyphi and typhimurium, Borrelia burgdorferi, Bartonella spp., Mycobacterium tuberculosis, Chlamydia pneumoniae, trachomatis and psittaci, Neisseria gonorrhoeae, Propionibacterium acnes, Tropheryma whippelii, Schistosoma mansoni, Opistorchis felineus, Strongyloides stercoralis, Taenia solium, Candida spp., Paracoccidioides brasiliensis, Histoplasma capsulatum and Trichomonas vaginalis can also be potential etiological agents of cancer. Apparently, detection of new associations between infectious agents and risk of the development of cancer will facilitate progress in elaboration of prophylaxis measures, early diagnostic methods and, probably, methods of treatment of malignant tumors. PMID:23163048
Abstract in spanish Leuconostoc es una cocácea grampositiva parecida a los Streptococcus, que se encuentra ampliamente distribuida en la naturaleza; es usada en la industria de vinos, productos lácteos y quesos para la producción de aromas y texturas. Leuconostoc causa ocasionalmente infecciones en humanos, puede producir bacteriemia, infección asociada a catéter, síndrome séptico, meningitis, neumonía, infección del tracto urinario, osteomielitis y compromiso hepático, entre otros (more) . Se describen como factores de riesgo para una infección por este agente: el síndrome de intestino corto, uso de catéter venoso central y la alimentación enteral por gastrostomía. Orientan a la presencia de este agente el aislamiento de una cocácea grampositiva, catalasa negativa, PYR y LAP negativas, resistente a vancomicina. El tratamiento de elección es penicilina o ampicilina Abstract in english Leuconostoc is a grampositive cocci, quite ubiquitous in nature. It is used in wine industry, and for aroma and texture of dairy products. Occasionally it has been isolated from humans in cases of bacteremia, catheter associated infections, sepsis, meningitis, pneumonia, UTI, osteomyelitis and hepatic dysfunction. Short bowel syndrome, patients with CVC and patients with gastrostomy undergoing enteral feeding, are described amongst the factors associated with this infecti (more) on. The isolation of a grampositive cocci, that does not hydrolyze arginine and that is resistant to vancomycin leads to this diagnostic possibility. Antibiotic treatment: penicillin or ampicillin
Abstract in english Background: Acute bacterial meningitis (ABM) is a serious disease that needs rapid diagnosis for an accurate treatment. The most important etiological agents are: Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b. Overall pathogen detection rate in patients with ABM in Chile is 83%. Aim: To evaluate a Polymerase Chain Reaction (PCR) protocol for simultaneous detection of several pathogens in patients with ABM. Material and methods: We desi (more) gned and evaluated a multiplex PCR protocol for simultaneous specific genes identifications of S pneumoniae (¡ytA and ply genes), N meningitidis (ctrA, crgA) and H influenzae (bexA) in cerebrospinal fluid (CSF) samples from pediatric patients with suspected diagnosis of ABM. Sensitivity, specificity and minimum detection levels of DNA were determined. Amplifications ofrDNA 16S gene was done to confirm extraction of bacterial DNA. Results: Ninety nine CSF samples were studied, 90 from children with fever and negative CSF culture, and 9 from ABM and positive culture patients. The PCR protocol had a sensitivity of 89%, specificity of 100%, positive predictive value 100% and negative predictive value 99%. Conclusions: We observed a high concordance (89%) between bacteriological cultures and the PCR protocol results. This diagnostic tool could increase identification of agents in specific settings such as patients previously treated with antibiotics
The pandemic of the swine-origin influenza A virus (S-OIV) in 2009 demonstrated severe viral pneumonia followed by acute respiratory distress syndrome (ARDS). Although ARDS would be caused by the influenza virus pneumonia itself, it has remained unclear whether other respiratory viral or bacterial infections coexist with S-OIV pneumonia. We report an immunocompetent patient with methicillin-resistant Staphylococcus aureus (MRSA) and Herpes simplex virus (HSV) pneumonia secondary to S-OIV infection. A 57-year-old man previously without major medical illness was admitted to our hospital with severe pneumonia accompanied by ARDS due to S-OIV. In his clinical course, anti-influenza treatment was not effective. Sputum culture revealed the presence of MRSA, and HSV was isolated in broncho-alveoler lavage (BAL) fluid. Administration of an antiviral agent (acyclovir), an antibacterial agent (linezolid), and a corticosteroid (methylprednisolone) successfully improved the pneumonia and ARDS. HSV pneumonia can scarcely be seen in healthy people. However recently it has been recognized as a ventilator-associated pneumonia. Although coexistence of Streptococcus pneumoniae and MRSA was reported in S-OIV pneumonia, secondary viral infection has not been reported. The present report is the first patient with HSV pneumonia secondary to S-OIV infection. We propose that a possibility of hidden HSV pneumonia should be taken into consideration in patients with prolonged severe pneumonia due to influenza infection.
Abstract in spanish La resistencia a los fármacos antibacterianos tiene particular importancia en América Latina. En este artículo se analiza la resistencia a los antimicrobianos de tres clases de bacterias de importancia clínica: bacterias grampositivas, enterobacterias y bacilos gramnegativos no fermentadores. Las bacterias grampositivas que producen infecciones humanas frecuentes son, en su mayoría, cocos: estafilococos, estreptococos (incluidos neumococos) y enterococos, tanto en el (more) medio comunitario como en el nosocomial. Esta situación no es diferente en la Región de las Américas. Entre las bacterias grampositivas, las que causan bacteriemia con mayor frecuencia corresponden a cepas de estafilococos coagulasa negativos, seguidas de las de enterococos. En este informe se analiza la resistencia de estas especies a distintos antimicrobianos, los mecanismos de resistencia para las cepas de origen hospitalario y comunitario y los nuevos medicamentos para tratar las infecciones por estas bacterias. La resistencia a los antimicrobianos de las cepas de Enterococcus en América Latina todavía es un problema menor en relación con la situación en los Estados Unidos de América. Las cepas del género Streptococcus aisladas de infecciones respiratorias aún son sensibles a penicilina. Por otra parte, la resistencia de las enterobacterias es de gran importancia en la Región, particularmente por la gran difusión de betalactamasas de espectro extendido (BLEE) de tipo CTX-M, algunas de las cuales se originaron en América Latina. En el presente artículo se analizan la situación de la resistencia de las cepas de Streptococcus pneumoniae, y de los estreptococos betahemolítico y del grupo viridans. Entre los bacilos gramnegativos no fermentadores, si bien las cepas de Pseudomonas aeruginosa siguen siendo la causa principal de bacteriemias, la proliferación de infecciones por cepas de Acinetobacter spp. tiene en algunas partes gran magnitud. En lo referente a los antibióticos, existen varias opciones para tratar infecciones por bacterias grampositivas. La situación terapéutica no es igual para las infecciones por enterobacterias y por bacilos gramnegativos no fermentadores, donde las opciones resultan aún insuficientes para el tratamiento adecuado de los pacientes. Abstract in english Antibacterial drug resistance is a particularly significant issue in Latin America. This article explores antimicrobial resistance in three classes of clinically important bacteria: gram-positive bacteria, enterobacteria, and nonfermenting gram-negative bacilli. The gram-positive bacteria frequently responsible for infections in humans are for the most part cocci: staphylococci, streptococci (including pneumococci), and enterococci, in both community and hospital settings (more) . This situation is no different in the Region of the Americas. Among the gram-positive bacteria, the causative agents of bacteremia are most commonly strains of coagulase-negative Staphylococcus, followed by enterococci. This report explores the resistance of these species to different antimicrobial drugs, resistance mechanisms in community and hospital strains, and new drugs for treating infections caused by these bacteria. In Latin America, antimicrobial resistance in Enterococcus strains is still a minor problem compared to the situation in the United States. The strains of the genus Streptococcus isolated from respiratory infections are still sensitive to penicillin. Furthermore, the resistance of enterobacteria is extremely important in the Region, particularly because of the broad dissemination of CTX-M extended-spectrum beta-lactamases (ESBL), some of which originated in Latin America. This article analyzes the resistance of Streptococcus pneumoniae, betahemolytic streptococci, and viridans group streptococci. Among the nonfermenting gram-negative bacilli, while Pseudomonas aeruginosa strains remain the leading cause of bacteremia, infections caused by strains of Acinetobacter spp. have proliferated extensively in some areas. With regard to antibiotics, several options are available for treating gram-positive bacterial infections. The same cannot be said for infections caused by enterobacteria and nonfermenting gram-negative bacilli, where options for the effective treatment of patients are still insufficient.
Abstract in portuguese Malassezia pachydermatis (Pityrosporum canis) faz parte da microbiota da pele e quando ocorrem alterações no microambiente local como aumento da umidade, da temperatura e do substrato, determinando uma elevação do número de células, ocorre a transição da forma comensal para o parasitismo. O objetivo deste trabalho foi determinar a prevalência da infeçâo por M. pachydermatis e outros agentes infecciosos nas otites externas e dermatites de cães. Foram analisadas (more) 78 amostras de cães com otite, 36 amostras de cães com o conduto auditivo normal e 24 com dermatite. Todas as amostras foram submetidas ao exame direto. cultivo em ágar sangue e em ágar Sabouraud dextrose, acrescido de cloranfenicol e cicloheximida. Ao exame direto, 50% das amostras de otite e 16,6% das amostras de dermatite apresentaram numerosas células semelhante a M. pachydermatis, enquanto 83,3% das amostras de ouvidos saudáveis apresentaram ausência de células com esta morfologia. M. pachydermatis foi isolada em 25% das amostras do conduto auditivo normal, em 80,7% das amostras de otite e em 37,5% das amostras de dermatite. Foram também isolados das amostras de otite Staphylococcus intermédias, S. aureus, S. epidermidis, Pseudomonas aeruginosa, Proteus sp, Actinomyces sp, Streptococcus sp e Otodectes cynotis e das de dermatite Staphylococcus intermédias, S. áureas, S. epidermidis Microsporum canis, M. gypseum,. Trychophyton sp e Demodex canis. M. pachydermatis foi o agente com maior prevalência nas otites externas e dermatites, sendo um agente oportunista que causa otite e dermatite quando há uma alteração do microambiente. Abstract in english The Malassezia pachydermatis ( Pityrosporum canis) is found in the whole skin microflora. It seems to occur as a consequence of changes in the local microenvironment, such as moist increase, temperature or substrate enhancement, generating a raising on cell quantity, which brings the transition from commensal form to parasitism. The purpose of this work was to evaluate the prevalence of M. pachydermatis infection and other infectious agents in external otitis and dog derm (more) atitis as well. We also examined 78 samples of dogs suffering from otitis, 36 samples of dogs having normal auditive tube and 24 having dermatitis. All samples were submitted to direct microscopic examination. They were cultured in blood agar, also in Sabouraud agar dextrose with cloranfenicol and cicloheximide. By direct examination showed that 50% of the samples on dogs with otitis and dermatitis 16.6% showed several cels resembling M. pachydermatis. However from healthy ear sample 83.3% did not present cells with this form. M. pachydermatis was isolated on 80.7% of otitis samples, on 25% of normal auditive tube samples and finally, 37.5% of dog dermatitis samples. It was isolated Staphylococcus intermedius, S. aureus, S. epidermidis, Pseudomonas aeruginosa, Proteus sp, Streptococcus sp and Otodectes cynotis from samples of animals with otitis. Cases of dermatites allowed also the isolation of Staphylococcus intermedius, S. aureus, S. epidermidis, Microsporum canis, M. gypseum, Trychophyton mentagophytes and Demodex canis. M. pachydermatis was the most prevalent agent in cases of external otitis and dermatitis, being an opportunistic agent, that cause otitis and dermatitis when thereis a change in the microenvironment
Aislamiento de bacterias gram positivas de leche cruda con residuos de antimicrobianos
Abstract in spanish Se recolectaron 200 muestras de leche cruda a nivel de cántaras en receptorías ubicadas en tres zonas de alta producción lechera del estado Zulia- Venezuela. Se aplicaron las pruebas del cloruro de trifenil tetrazolio (CTT) y el disco ensayo para detectar presencia de antimicrobianos. Las muestras positivas se sembraron en caldo soya tripticasa, agar sangre humana y agar manitol salado para realizar el aislamiento de bacterias Gram positivas. La identificación de espe (more) cies se realizó a través de pruebas bioquímicas. Se encontró que 45 muestras (22,5%) de leche analizadas contenían antimicrobianos, obteniéndose crecimiento bacteriano en 35 de ellas. Se aislaron 100 cepas, que se distribuyeron en los siguientes géneros: 44 Staphylococcus, 19 Streptococcus, 17 Enterococcus, 9 Bacillus, 4 Micrococcus, 4 Corynebacterium y 3 Lactococcus. La especie más frecuentemente aislada fue el S. aureus, principal agente productor de mastitis bovina en el estado Zulia, y microorganismo frecuentemente asociado en el país con intoxicaciones alimentarias vehiculizadas por queso elaborado con leche cruda. Se recomienda aplicar programas de control para el uso de antibióticos Abstract in english Isolation of Gram-positive bacteria from raw milk with antimicrobial residues. Two hundred samples of raw milk were collected at the receiving plants located in three areas of high milk production in Zulia state, Venezuela. The CTT test and trial disk were used in order to detect the presence of antimicrobials. The positive samples were inoculated in tripticase soy broth, human blood agar and manitol salt agar in order to isolate Gram-positive bacterias. The identificatio (more) n of species was performed through biochemical tests. It was found that 45 samples (22,5%) of analyzed milk contained antimicrobials, and bacterial growth was obtained in 35 of them. 100 strains were isolated namely: 44 Staphylococcus, 19 Streptococcus, 17 Enterococcus, 9 Bacillus, 4 Micrococcus, Corynebacterium and 3 Lactococcus. The most frecuently isolate specie was S. aureus, the main producing agent of bovine mastitis in Zulia state, a microorganism frequently associated in the country to food-borne intoxications, associated to cheese processed from raw milk. It is recommended to apply control programs for the of antibiotics
Abstract in portuguese A própolis é uma resina natural coletada e modificada por abelhas, que tem sido usada como agente quimioterápico desde a antigüidade. A ação antibacteriana desse composto foi avaliada através da inoculação de placas de ágar BHI, contendo 5% de extrato alcóolico de própolis a 50%, com um inóculo bacteriano de 1 x 10(6) células.mL-1. Foram testados 161 isolados bacterianos, tanto gram positivos (Staphylococcus sp., Streptococcus sp., Nocardia asteroides e Rhod (more) ococcus equi), como gram negativos (Escherichia coli, Salmonella sp., Proteus mirabilis e Pseudomonas aeruginosa). Os isolados foram considerados sensíveis ao extrato de própolis quando não ocorreu crescimento bacteriano na placa após 72 horas de incubação a 37ºC. Utilizaram-se, como controle, meios acrescidos de 5% de álcool etílico e 5% de solução salina. O extrato de própolis demonstrou atividade antibacteriana por inibir o crescimento de 67,7% das bactérias testadas; 92,6% dos isolados Gram positivos e 42,5% dos Gram negativos foram sensíveis ao extrato. O extrato alcóolico de própolis a 50% avaliado foi capaz de exercer ação antibacteriana efetiva contra a maioria dos isolados testados. Abstract in english Propolis is a natural resin collected and modified by honeybees. Since ancient times it has been used as a chemotherapeutic agent. The propolis antibacterial activity was evaluated through bacterial inoculation on BHI agar plates with 5% of alcoholic propolis extract (10(6) bacteria. mL-1). One hundred and sixty one bacterial strains were evaluated, as Gram positive bacteria (Staphylococcus sp., Streptococcus sp., Nocardia asteroides and Rhodococcus equi) as Gram negative (more) (Escherichia coli, Salmonella sp., Proteus mirabilis and Pseudomonas aeruginosa). The strain was considered sensible to the propolis extract when no bacterial growth was evident on the plate after 72 hours at 37ºC. The control test used agar plates with 5% of ethanol (M2) and 5% of saline solution. Propolis extract demonstrated antibacterial activity on 67.7% of the tested strains; 92.6% of Gram-positive and 42.5% of Gram-negative strains presented sensitivity. The propolis extract showed effective antibacterial activity against the majority of tested strains.
Abstract in portuguese Streptococcus mutans, principal microrganismo da cavidade oral, desempenha papel preponderante na formação de placas dentárias, sendo considerado o agente etiológico primário da cárie. Rheedia gardneriana, conhecida popularmente como bacupari, é uma planta utilizada com fins medicinais para o tratamento de diversas patologias, e por apresentar atividade antimicrobiana de compostos das folhas contra bactérias Gram-positivas e Gram-negativas. O objetivo do presente (more) trabalho foi avaliar o efeito de extrato de semente de R. gardneriana sobre a cepa S. mutans UA159. Os testes foram conduzidos com o extrato etanólico bruto e as frações obtidas com os solventes diclorometano, etanol-água, metanol e hexano, em ensaios de inibição in vitro. O extrato bruto (100%) apresentou halos de inibição com diâmetro similar ao obtido com solução de digluconato de clorexidina 0,12%, usada como controle. Os ensaios com a fração diclorometano exibiram atividade inibitória 35% menor comparado com o controle, enquanto nenhum efeito antimicrobiano foi observado com a fração etanol-água. Contrariamente, os resultados obtidos com as frações hexânica e metanólica demonstraram claramente a atividade antimicrobiana por inibição do crescimento bacteriano. Na fração metanólica a formação de halos de inibição foi similar ao do controle. Estes dados apresentam atividade antimicrobiana de R. gardneriana contra S. mutans. Abstract in english Streptococcus mutans, which is the main microorganism of the oral cavity, plays a preponderant role in dental plaque formation and is considered the primary etiologic agent regarding caries. Commonly known as "bacupari", Rheedia gardneriana is a plant used for medicinal purposes in the treatment of several pathologies; besides, its leaves have compounds that present antimicrobial activity against Gram-positive and Gram-negative bacteria. The aim of this work was to evalua (more) te the effect of R. gardneriana seed extract on S. mutans strain UA159. The tests were carried out with crude ethanol extract and the fractions obtained with the solvents dichloromethane, ethanol-water, methanol, and hexane in in vitro inhibition assays. The crude extract (100%) presented inhibition halos with diameter similar to that obtained by using 0.12% chlorhexidine digluconate solution as control. Assays with the fraction dichloromethane showed an inhibitory activity 35% lower than that of the control, whereas no antimicrobial effect was observed with the ethanol-water fraction. Conversely, the results obtained with the fractions hexane and methanol clearly demonstrated antimicrobial activity by inhibiting the bacterial growth. In the methanol fraction, the formation of inhibition halos was similar to that in the control. These data present antimicrobial activity of R. gardneriana against S. mutans.
Use of a bacteriophage lysin, PlyC, as an enzyme disinfectant against Streptococcus equi.
Streptococcus equi is the causative agent of the purulent infection equine strangles. This disease is transmitted through shedding of live bacteria from nasal secretions and abscess drainage or by contact with surfaces contaminated by the bacteria. Disinfectants are effective against S. equi, but inactivation by environmental factors, damage to equipment, and toxicity are of great concern. Bacteriophage-encoded lysins (cell wall hydrolases) have been investigated as therapeutic agents due to their ability to lyse susceptible gram-positive organisms. Here, we investigate the use of one lysin, PlyC, as a narrow-spectrum disinfectant against S. equi. This enzyme was active against >20 clinical isolates of S. equi, including both S. equi subsp. equi and S. equi subsp. zooepidemicus. Significantly, PlyC was 1,000 times more active on a per weight basis than Virkon-S, a common disinfecting agent, with 1 microg of enzyme able to sterilize a 10(8) CFU/ml culture of S. equi in 30 min. PlyC was subjected to a standard battery of tests including the Use Dilution Method for Testing Disinfectants and the Germicidal Spray Products Test. Results indicate that aerosolized PlyC can eradicate or significantly reduce the S. equi load on a variety of materials found on common stable and horse-related equipment. Additionally, PlyC was shown to retain full activity under conditions that mimic a horse stable, i.e., in the presence of nonionic detergents, hard water, or organic materials. We propose PlyC as the first protein-based, narrow-spectrum disinfectant against S. equi, which may augment or supplement the use of broad-spectrum disinfectants in barns and stables where equine strangles is prevalent. PMID:19139235
Use of a Bacteriophage Lysin, PlyC, as an Enzyme Disinfectant against Streptococcus equi?
Streptococcus equi is the causative agent of the purulent infection equine strangles. This disease is transmitted through shedding of live bacteria from nasal secretions and abscess drainage or by contact with surfaces contaminated by the bacteria. Disinfectants are effective against S. equi, but inactivation by environmental factors, damage to equipment, and toxicity are of great concern. Bacteriophage-encoded lysins (cell wall hydrolases) have been investigated as therapeutic agents due to their ability to lyse susceptible gram-positive organisms. Here, we investigate the use of one lysin, PlyC, as a narrow-spectrum disinfectant against S. equi. This enzyme was active against >20 clinical isolates of S. equi, including both S. equi subsp. equi and S. equi subsp. zooepidemicus. Significantly, PlyC was 1,000 times more active on a per weight basis than Virkon-S, a common disinfecting agent, with 1 ?g of enzyme able to sterilize a 108 CFU/ml culture of S. equi in 30 min. PlyC was subjected to a standard battery of tests including the Use Dilution Method for Testing Disinfectants and the Germicidal Spray Products Test. Results indicate that aerosolized PlyC can eradicate or significantly reduce the S. equi load on a variety of materials found on common stable and horse-related equipment. Additionally, PlyC was shown to retain full activity under conditions that mimic a horse stable, i.e., in the presence of nonionic detergents, hard water, or organic materials. We propose PlyC as the first protein-based, narrow-spectrum disinfectant against S. equi, which may augment or supplement the use of broad-spectrum disinfectants in barns and stables where equine strangles is prevalent.
Suprathel-antiseptic matrix: in vitro model for local antiseptic treatment?
Acetic acid is a traditional antiseptic agent that has been used for more than 6000 years. The main goal of this study was to demonstrate the suitability of Suprathel (PolyMedics Innovations GmbH, Denkendorf, Germany) in combination with various antiseptic agents to create an "antiseptic-matrix" especially designed for problematic microorganisms such as Proteus vulgaris, Acinetobacter baumannii, or Pseudomonas aeruginosa, which are frequently associated with burns. The study was designed to test the in vitro antimicrobial effect of a "Suprathel-antiseptic matrix" (Suprathel combined with acetic acid 3%, povidone-iodine 11% [Betaisodona], polyhexanide 0.04% [Lavasept], phenoxyethanol 2%/octenidine dihydrochloride 0.1% [Octenisept], mafenide acetate 5%, and chlorhexidine gluconate 1.5%/cetrimid 15% [Hibicet]). As a means to assess the typical bacterial spectrum of a burn unit, the following Gram-negative and Gram-positive bacteria strains were tested: Escherichia coli, P vulgaris, P aeruginosa, A baumannii, Enterococcus faecalis, Staphylococcus epidermidis, Staphylococcus aureus, methicillin-resistant S aureus, and ?-hemolytic streptococcus groups A and B. The tests showed a positive bactericidal effect of the Suprathel-antiseptic matrix, particularly with problematic Gram-negative bacteria such as P vulgaris, P aeruginosa, and A baumannii, except for the combination of Suprathel and mafenide acetate. It can be concluded that Suprathel-antiseptic matrix appears to be suitable as a local antiseptic agent, but clinical studies need to be performed to confirm these in vitro observations. The authors' previous studies have shown that acetic acid demonstrates a wide antiseptic spectrum for microorganisms typically found in burn patients. The combination of Suprathel and acetic acid worked well in this study and appears to be promising for future clinical application. PMID:21242734
The antimicrobial effect of acetic acid--an alternative to common local antiseptics?
Acetic acid has been commonly used in medicine for more than 6000 years for the disinfection of wounds and especially as an antiseptic agent in the treatment and prophylaxis of the plague. The main goal of this study was to prove the suitability of acetic acid, in low concentration of 3%, as a local antiseptic agent, especially for use in salvage procedures in problematic infections caused by organisms such as Proteus vulgaris, Acinetobacter baumannii or Pseudomonas aeruginosa. This study was designed to compare the in vitro antimicrobial effect of acetic acid with those of common local antiseptics such as povidone-iodine 11% (Betaisodona), polyhexanide 0.04% (Lavasept), mafenide 5% and chlohexidine gluconate 1.5% cetrimide 15% (Hibicet). Former studies suggest the bactericidal effect of acetic acid, but these data are very heterogeneous; therefore, a standardised in vitro study was conducted. To cover the typical bacterial spectrum of a burn unit, the following Gram-negative and Gram-positive bacterial strains were tested: Escherichia coli, P. vulgaris, P. aeruginosa, A. baumannii, Enterococcus faecalis, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA) and beta-haemolytic Streptococcus group A and B. The tests showed excellent bactericidal effect of acetic acid, particularly with problematic Gram-negative bacteria such as P. vulgaris, P. aeruginosa and A. baumannii. The microbiological spectrum of acetic acid is wide, even when tested at a low concentration of 3%. In comparison to our currently used antiseptic solutions, it showed similar - in some bacteria, even better - bactericidal properties. An evaluation of the clinical value of topical application of acetic acid is currently underway. It can be concluded that acetic acid in a concentration of 3% has excellent bactericidal effect and, therefore, seems to be suitable as a local antiseptic agent, but further clinical studies are necessary. PMID:19286325
Antimicrobial resistance in respiratory pathogens isolated in Brazil during 1999-2000
Abstract in english The in vitro antimicrobial susceptibility of the respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis to commonly tested and prescribed agents was investigated during 1999-2000 and compared with results obtained during a previous 1997-1998 study. Of 448 isolates of S. pneumoniae collected and tested in 1999-2000, 77.2% were susceptible, 19.9% were intermediate, and 2.9% were resistant to penicillin, demonstrating that there wer (more) e no major changes in susceptibility to penicillin from 1997-1998 (77.1% susceptible, 18.7% intermediate, 4.2% resistant). All S. pneumoniae isolates from 1999-2000 were susceptible to levofloxacin and vancomycin, and >90% were susceptible to the beta-lactams (amoxicillin-clavulanate, ceftriaxone, and cefuroxime) and macrolides (azithromycin and clarithromycin), showing that susceptibility to these agents also remained unchanged since 1997-1998. The most notable increase in resistance between the two studies was demonstrated by trimethoprim-sulfamethoxazole, which increased from 23.4% to 38.6%. Penicillin resistance correlated with resistance to beta-lactams, macrolides, and trimethoprim-sulfamethoxazole in both studies. In H. influenzae, the prevalence of beta-lactamase-producing isolates remained unchanged (10.6% in 1999-2000; 11.0% in 1997-1998). All H. influenzae isolates were susceptible to levofloxacin, ceftriaxone, cefuroxime, and azithromycin, and showed no change between the two studies. Trimethoprim-sulfamethoxazole resistance was present in 40.1% of isolates in 1999-2000, and in 45.2% in 1997-1998. In M. catarrhalis, the prevalence of beta-lactamase-producing isolates was unchanged (97.9% in 1999-2000; 98.0% in 1997-1998). The most active agents against M. catarrhalis were azithromycin (MIC90,
Clostridium perfringens: toxinotype and genotype
Background Evidence-based priority setting is increasingly important for rationally distributing scarce health resources and for guiding future health research. We sought to quantify the contribution of a wide range of infectious diseases to the overall infectious disease burden in a high-income setting. Methodology/Principal Findings We used health-adjusted life years (HALYs), a composite measure comprising premature mortality and reduced functioning due to disease, to estimate the burden of 51 infectious diseases and associated syndromes in Ontario using 2005–2007 data. Deaths were estimated from vital statistics data and disease incidence was estimated from reportable disease, healthcare utilization, and cancer registry data, supplemented by local modeling studies and national and international epidemiologic studies. The 51 infectious agents and associated syndromes accounted for 729 lost HALYs, 44.2 deaths, and 58,987 incident cases per 100,000 population annually. The most burdensome infectious agents were: hepatitis C virus, Streptococcus pneumoniae, Escherichia coli, human papillomavirus, hepatitis B virus, human immunodeficiency virus, Staphylococcus aureus, influenza virus, Clostridium difficile, and rhinovirus. The top five, ten, and 20 pathogens accounted for 46%, 67%, and 75% of the total infectious disease burden, respectively. Marked sex-specific differences in disease burden were observed for some pathogens. The main limitations of this study were the exclusion of certain infectious diseases due to data availability issues, not considering the impact of co-infections and co-morbidity, and the inability to assess the burden of milder infections that do not result in healthcare utilization. Conclusions/Significance Infectious diseases continue to cause a substantial health burden in high-income settings such as Ontario. Most of this burden is attributable to a relatively small number of infectious agents, for which many effective interventions have been previously identified. Therefore, these findings should be used to guide public health policy, planning, and research. PMID:10203838
Adenosine Triphosphate Pool During the Growth Cycle in Streptococcus faecalis
Forrest, W. W. (University of Adelaide, Adelaide, South Australia). Adenosine triphosphate pool during the growth cycle in Streptococcus faecalis. J. Bacteriol. 90:1013–1018. 1965.—The adenosine triphosphate (ATP) pool has been studied throughout the growth cycle of Streptococcus faecalis. Normally,...
GROWTH STIMULATION OF STREPTOCOCCUS FAECALIS VAR. LIQUEFACIENS BY CANAVANINE1
Hammel, Jay M. (The Pennsylvania State University, University Park) and L. N. Zimmerman. Growth stimulation of Streptococcus faecalis var. liquefaciens by canavanine. J. Bacteriol. 86:490–493. 1963.—l-Canavanine, a competitive inhibitor of arginine, was found to stimulate the growth of Streptococcus...
Effects of Lactic Acid Bacteria and Organic Acids on Growth and Germination of Bacillus cereus
Growth and germination of vegetative cells and endospores of Bacillus cereus were affected by Streptococcus lactis, Streptococcus thermophilus, Lactobacillus acidophilus, and Lactobacillus bulgaricus in nonfat milk medium and by salts of organic acids in broth medium. Growth of the lactic acid bacte...
The caramel odor associated with the "Streptococcus milleri" group was shown to be attributable to the formation of the metabolite diacetyl. Levels of diacetyl in the 22- to 200-mg/liter range were produced by 68 strains of the "S. milleri" group; apart from one strain of Streptococcus mutans, all 9...
We report the first case of infection due to Streptococcus oligofermentans, which is a recently described oral Streptococcus species. It was responsible for the endocarditis and left forearm abscess of a 43-year-old woman. Identification was made using molecular techniques performed directly from va...
Streptococcus agalactiae (group B streptococcus [GBS]) is a pathogen that causes meningoencephalitis in Nile tilapia (Oreochromis niloticus). Here, we reported the complete genome sequence of S. agalactiae strain ZQ0910, which was isolated from the GIFT strain of Nile tilapia in Guangdong, China. PMID:22933761
Recently, strains of Streptococcus bovis were reclassified as Streptococcus gallolyticus. In the present study we describe for the first time an outbreak of S. gallolyticus in a broiler flock. Mortality during the first week was normal (tannase activity, identified for the first time avian isolates belonging to S. gallolyticus subsp. gallolyticus. However, these investigations also demonstrated a clear heterogeneity with pigeon isolates.
Recently, strains of Streptococcus bovis were reclassified as Streptococcus gallolyticus. In the present study we describe for the first time an outbreak of S. gallolyticus in a broiler flock. Mortality during the first week was normal (tannase activity, identified for the first time avian isolates belonging to S. gallolyticus subsp. gallolyticus. However, these investigations also demonstrated a clear heterogeneity with pigeon isolates. PMID:17166965
Regions of the Streptococcus sobrinus spaA gene encoding major determinants of antigen I.
Surface protein antigen A (SpaA), also called antigen B, antigen I/II, or antigen P1, is an abundant cell envelope protein that is the major antigenic determinant of Streptococcus sobrinus and other members of the Streptococcus mutans group of cariogenic bacteria. This laboratory has previously repo...
Most members of the Streptococcus mutans group of microorganisms specify a major cell surface-associated protein, SpaA, that is defined by its antigenic properties. The region of the spaA gene from Streptococcus sobrinus 6715 encoding the immunodominant determinant of the major antigenic component (...
The global burden of group A streptococcal diseases.
Genomic analysis of type emm59 group A Streptococcus invasive strains isolated in the United States discovered higher than anticipated genetic heterogeneity among strains and identified a heretofore unrecognized monoclonal cluster of invasive infections in the San Francisco Bay area. Heightened monitoring for a potential shift in the epidemic behavior of emm59 group A Streptococcus is warranted. PMID:16253886
Genomic analysis of emm59 group A Streptococcus invasive strains, United States.
Genomic analysis of type emm59 group A Streptococcus invasive strains isolated in the United States discovered higher than anticipated genetic heterogeneity among strains and identified a heretofore unrecognized monoclonal cluster of invasive infections in the San Francisco Bay area. Heightened monitoring for a potential shift in the epidemic behavior of emm59 group A Streptococcus is warranted. PMID:22469010
The antibiotic resistance group B streptococcal plasmids, pIP501 and pVA797, were conjugally transferred from Streptococcus faecalis to Lactobacillus plantarum. The Escherichia coli-Streptococcus shuttle plasmids, pVA838 and pSA3, were mobilized from S. sanguis to L. plantarum by pVA797 via cointegr...
THE VIABILITY OF HEMOLYTIC STREPTOCOCCUS IN CERTAIN SOLUTIONS CONTAINING GELATIN
1. The findings of Robertson, Sia, and Woo with regard to the preservative action of 0.1 per cent gelatin in suspending fluids for the pneumococcus have been confirmed for the streptococcus. 2. In gelatin-citrate, gelatin-Locke's, and gelatin-"20:1" solutions, the streptococcus will live for 3 days...
pH activity profiles and inhibitor sensitivities were compared for membrane ATPases isolated from three oral lactic acid bacteria, Lactobacillus casei ATCC 4646, Streptococcus mutans GS-5, and Streptococcus sanguis NCTC 10904, with, respectively, high, moderate, and low levels of acid tolerance. Mem...
The effects of immunization with antigens of the Streptococcus mutans glucosyltransferase (GTF) complex on oral challenge with two Streptococcus sanguis strains (H7PR3 and 34) in hamsters were studied. Antisera to S. mutans GTF complex were able to inhibit one-third (strain H7PR3) to one-half (strai...
The complete nucleotide sequence was determined for the Streptococcus downei (previously Streptococcus sobrinus) MFe28 gtfS gene which specifies a glucosyltransferase (GTF-S) producing water-soluble glucan. A single open reading frame which encodes a mature protein with a molecular weight of 147,408...
STARCH HYDROLYSIS BY STREPTOCOCCUS EQUINUS
Dunican, Lawrence K. (Cornell University, Ithaca, N. Y.) and Harry W. Seeley. Starch hydrolysis by Streptococcus equinus. J. Bacteriol. 82:264–269. 1962.—In a study of starch hydrolysis by strains of Streptococcus equinus, 52 isolates were obtained and their amylolytic abilities determined. It was f...
Oral immunization of humans with Streptococcus sobrinus glucosyltransferase.
The effect of oral administration of glucosyltransferase (GTF) from Streptococcus sobrinus 6715 on levels of immunoglobulin A (IgA) antibody to GTF in parotid saliva and on the number of indigenous Streptococcus mutans in the whole saliva was studied in young adult males. GTF combined with aluminum ...
A 0.8-kb HindIII-BamHI internal fragment of the Streptococcus mutans wall-associated protein A gene (wapA) was ligated to the 5.1-kb HindIII-BamHI fragment of the chimeric Streptococcus-Escherichia coli plasmid pVA891 (Emr Cmr). The resulting construct was used to transform S. mutans GS-5, and eryth...
Glucose uptake was examined by using whole-cell suspensions of Streptococcus mutans (strains BHT, Ingbritt, and GS-5), Streptococcus mitis (strains 9811 and 72×41), and Actinomyces viscosus (strains T6 and WVU626) incubated for up to 90 min in 0 to 82% (vol/vol) human whole salivary supernatant. Glu...
Growth of several cariogenic strains of oral streptococci in a chemically defined medium.
A chemically defined medium in which Streptococcus mutans strains AHT, BHT, GS-5, JC-2, Ingbritt, At6T, At9T, 6715, and OMZ-176 and Streptococcus salivarius strain HHT grew rapidly to high turbidities was formulated. Maximal turbidities of each strain were observed after 8 to 12 h of aerobic growth....
Streptococcus agalactiae (group B streptococcus [GBS]) is a leading cause of neonatal pneumonia, sepsis, and meningitis. Early-onset GBS pneumonia is characterized by marked pulmonary epithelial and endothelial cell injury. Innate proinflammatory responses to GBS infection that may contribute to the...
EXTRACELLULAR PROTEINASE OF STREPTOCOCCUS LACTIS1
Williamson, W. T. (North Carolina State of the University of North Carolina, Raleigh), S. B. Tove, and M. L. Speck. Extracellular proteinase of Streptococcus lactis. J. Bacteriol. 87:49–53. 1964.—Streptococcus lactis was shown to produce an extracellular proteolytic enzyme(s). A 120-fold purificatio...
Effect of Plasmid Incompatibility on DNA Transfer to Streptococcus cremoris
Several Streptococcus cremoris strains were used in protoplast transformation and interspecific protoplast fusion experiments with Streptococcus lactis and Bacillus subtilis, with pGKV110, pGKV21, and ?pAM?1 as the marker plasmids. ?pAM?1 is a 15.9-kilobase nonconjugative, deletion derivative of pAM...
PcsB is a protein of unknown function that plays a critical role in cell division in Streptococcus pneumoniae and other ovococcus species of Streptococcus. We constructed isogenic sets of mutants expressing different amounts of PcsB in laboratory strain R6 and virulent serotype 2 strain D39 to evalu...
A pyrosequencing method for detection and quantification of macrolide resistance mutations at positions 2058 and 2059 (Escherichia coli numbering) of the 23S rRNA gene is described. The method was developed and tested for Streptococcus pneumoniae, Streptococcus pyogenes, Mycobacterium avium, Campylo...
In 2002, we reported the discovery of a novel species of viridans streptococcus, Streptococcus sinensis. Recently, we reported the isolation of two more strains of S. sinensis. Clinically, S. sinensis is a definite cause of infective endocarditis, a characteristic mainly pertaining to the mitis grou...
The complexes of tailor made ligands with life essential metal ions may be an emerging area to answer the problems of multi drug resistance. The coordination complexes of VO(II), Co(II), Ni(II) and Cu(II) with the Schiff bases derived from isatin with 3-chloro-4-floroaniline and 2-pyridinecarboxaldehyde with 4-aminoantipyrine have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, molar conductance, electronic spectra, FT-IR, FAB mass and magnetic susceptibility measurements. FAB mass data show degradation of complexes. Both the ligands behave as bidentate and tridentate coordinating through O and N donor. The complexes exhibit coordination number 4, 5 or 6. The Schiff base and metal complexes show a good activity against the bacteria; Staphylococcus aureus, Escherichia coli and Streptococcus fecalis and fungi Aspergillus niger, Trichoderma polysporum, Candida albicans and Aspergillus flavus. The antimicrobial results also indicate that the metal complexes are better antimicrobial agents as compared to the Schiff bases. The minimum inhibitory concentrations of the metal complexes were found in the range 10~40 µg/mL. PMID:22783130
We evaluated the influence of molecular mass and degree of deacetylation of chitosan on the adsorption of Streptococcus sobrinus 6715 to saliva-treated hydroxyapatite (S-HA) by measuring the optical density of the bacterial cell suspensions released from saliva-treated hydroxyapatite. Twenty-five chitosan samples with different molecular masses (0.8-6kDa) and degrees of deacetylation (10-95%) were prepared for the study. We found that the inhibition of adsorption of S. sobrinus 6715 to S-HA correlated positively with the molecular mass of chitosan (R=0.876) and that the optimal degree of deacetylation was 50-60% for maximum inhibition of bacterial binding to S-HA. We also examined the effect of chitosan on zeta potentials of the oral bacteria and their surface hydrophobicities. It was observed that chitosan reduced the magnitude of the zeta potential and surface hydrophobicities of the oral bacteria. Thus, the results demonstrated that chitosan with a molecular mass of 5-6kDa and a degree of deacetylation of 50-60% might have the potential to act as an effective anti-plaque agent because of its polycationic properties.
Bacteriostatic effect of copaiba oil (Copaifera officinalis) against Streptococcus mutans.
This study evaluated the inhibitory activity of copaiba oil (Copaifera officinalis against the cariogenic microorganism, Streptococcus mutans. For such purpose, a minimum inhibition concentration test of copaiba oil against S. mutans was performed, using the serial dilution in broth technique, with a negative control, a positive control (0.12% chlorhexidine) and a 10% copaíba oil solution as a test. A minimum bactericidal concentration test with tubes presenting microbial inhibition was also conduced. In the minimum inhibitory concentration test, copaiba oil showed inhibition of bacterial growth at all concentrations tested up to 0.78 µL/mL of the 10% copaiba oil solution in the broth. In addition, the negative control had no inhibition, and the 0.12% chlorhexidine solution was effective up to 6.25 µL/mL in the broth. Copaiba oil showed a bacteriostatic activity against S. mutans at low concentrations, and could be a an option of phytotherapic agent to be used against cariogenic bacteria in the prevention of caries disease. PMID:22460312
Much antibiotic prescribing is based upon irrational practice rather than scientific principles. The advent and the better understanding of the pharmacokinetics and pharmacodynamics of antimicrobials are slowly leading to a change whereby antibiotics are prescribed with a better rationale. The fundamental understanding of the pharmacokinetics of the antimicrobial, for example how well it is absorbed, metabolized, distributed and eliminated from the body, should lead to an appreciation of the correct dosing interval. Pharmacodynamic factors, in particular, appreciation of the MIC of an antimicrobial for an infecting pathogen and whether time-independent or -dependent killing occurs, will also have a profound influence upon how an antimicrobial is used. This review attempts to consider these features as they apply to nasopharyngeal carriage of Streptococcus pneumoniae. The reason for the dosing and dosing frequency of a number of agents is discussed and an attempt is made to point the way to more judicious antibiotic prescribing so as to maximize clinical efficacy yet minimize the possibility of resistance emerging during therapy. PMID:12556433
Tobramycin for the treatment of bacterial pneumonia in children.
INTRODUCTION: Common etiological agents for community-acquired lower respiratory tract infection (LRTI) include Streptococcus pneumoniae, Hemophilus influenzae and Mycoplasma pneumoniae and can be easily managed with oral or intravenous antibiotics. However, LRTI in patients with underlying illnesses, such as cystic fibrosis (CF) and immune deficiency, or on ventilator support is difficult to manage because these are caused by Gram-negative bacilli. Tobramycin has been shown to be effective in the management of these patients. AREAS COVERED: Information about the antimicrobial activity, pharmacological aspects (including pharmacokinetics and pharmacodynamics), clinical efficacy, safety and side effects of tobramycin have been covered in this review. EXPERT OPINION: A major advance for the use of tobramycin has occurred with its use by the inhalational route, in children with CF. The inhalation route provides the advantage of ease of administration for prolonged periods at home and allows use of very high doses. Systematic reviews suggest that tobramycin inhalation improves outcome, decreases the need for hospitalization and decreases the need for use of frequent systemic antibiotics in CF patients colonized with pseudomonas. Data on the efficacy of inhaled tobramycin in non-CF bronchiectasis are scarce, as are data on the prevention and treatment of ventilator-associated pneumonia, and on the role of combining inhaled tobramycin with systemic tobramycin. Despite limitations, this drug has the potential to be used in various conditions other than CF. PMID:22292783
Rapid evolution of RNA genomes
Streptococcus suis is an important swine pathogen and an emerging zoonotic agent of septicemia and meningitis. Knowledge on host immune responses towards S. suis, and strategies used by this pathogen for subversion of these responses is scarce. The objective of this study was to identify the immune receptors involved in S. suis recognition by dendritic cells (DCs). Production of cytokines and expression of co-stimulatory molecules by DCs were shown to strongly rely on MyD88-dependent signaling pathways, suggesting that DCs recognize S. suis and become activated mostly through Toll-like receptor (TLR) signaling. Supporting this fact, TLR2?/? DCs were severely impaired in the release of several cytokines and the surface expression of CD86 and MHC-II. The release of IL-12p70 and CXC10, and the expression of CD40 were found to depend on signaling by both TLR2 and TLR9. The release of IL-23 and CXCL1 were partially dependent on NOD2. Finally, despite the fact that MyD88 signaling was crucial for DC activation and maturation, MyD88-dependent pathways were not implicated in S. suis internalization by DCs. This first study on receptors involved in DC activation by S. suis suggests a major involvement of MyD88 signaling pathways, mainly (but not exclusively) through TLR2. A multimodal recognition involving a combination of different receptors seems essential for DC effective response to S. suis. PMID:7041255
INTRODUCTION: Bacterial resistance is increasing on a global basis, making treatment options more limited. The development of new agents to meet this threat is a matter of urgency. Ceftaroline fosamil , a member of an advanced cephalosporin class of antimicrobials, is currently approved by the US Food and Drug Administration for use in for acute bacterial skin and skin structure infection (ABSSSI) and community-acquired bacterial pneumonia. Ceftaroline displays activity against Gram-positive and Gram-negative bacteria, including both methicillin-susceptible and resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae (including penicillin- and ceftriaxone-resistant strains), respiratory pathogens (such as Moraxella catarrhalis and Haemophilus influenzae, including beta-lactamase-producing strains) and limited coverage against Enterobacteriaceae. AREAS COVERED: Chemistry, mechanism of action, spectrum of activity, resistance, pharmacokinetics/pharmacodynamics, indications for use, safety and special populations are covered in this review. EXPERT OPINION: Ceftaroline's unique activity against MRSA and penicillin- and ceftriaxone-resistant S. pneumoniae strains is due to its high affinity for penicillin binding protein (PBP)-2a and PBP-2x, respectively. In randomized, double-blinded, clinical trials, ceftaroline fosamil was found to be non-inferior to ceftriaxone for the treatment CABP and to vancomycin plus aztreonam for ABSSSI. Substantial differences between the cephalosporins exist. Ceftaroline has unique characteristics that may make it useful in specific clinical circumstances, especially against multi-drug-resistant Gram-positive organisms. PMID:22594846
Levofloxacin for the treatment of respiratory tract infections.
INTRODUCTION: Fluoroquinolone use has dramatically increased since the introduction of the first respiratory fluoroquinolone in the late 1990s. Levofloxacin , like other fluoquinolones, is a potent antibiotic, due to high levels of susceptibility among Gram-negative, Gram-positive (including penicillin-resistant strains of Streptococcus pneumonia) and atypical pathogens. Levofloxacin is recommended for the treatment of community-acquired pneumonia (CAP), hospital-acquired pneumonia (HAP) and in the management of acute exacerbations of chronic bronchitis (AECB). Levofloxacin demonstrates good safety, bioavailability and tissue penetration, thus maintaining adequate concentrations at the site of infection. High-dose (750 mg), short-course (5 days) therapy regimens may offer improved treatment, especially in HAP, due to higher drug concentrations, increased adherence and the potential to reduce the development of resistance. AREAS COVERED: This article covers medical literature published in any language since 1990 until November 2011, on 'levofloxacin', identified using PubMed and MEDLINE. The search terms used were 'levofloxacin' and 'community acquired pneumonia', 'hospital pneumonia' or 'AECB'. EXPERT OPINION: Levofloxacin is a valuable antimicrobial agent and an optimal treatment option for AECB, CAP (as a monotherapy) and HAP (as combination therapy at a high-dose regimen). Its improved bioavailability and safety profile makes the possibility of shorter hospital stays a reality. PMID:22594848
Bacterial skin and soft tissues infections (SSTI) often determine acute disease and frequent emergency recovering, and they are one of the most common causes of infection among groups of different ages. Given the variable presentation of SSTI, a thorough assessment of their incidence and prevalence is difficult. The presence of patient-related (local or systemic) or environmental risk factors, along with the emergence of multi-drug resistant pathogens, can promote SSTI. These infections may present with a wide spectrum of clinical features and different severity, and can be classified according to various criteria. Many bacterial species can cause SSTI, but Gram-positive bacteria are the most frequently isolated, with a predominance of Staphylococcus aureus and Streptococcus pyogenes. The diagnosis of SSTI requires an extended clinical history, a thorough physical examination and a high index of suspicion. Early diagnosis is particularly important in complicated infections, which often require laboratory studies, diagnostic imaging and surgical exploration. SSTI management should conform to the epidemiology, the aetiology, the severity and the depth of the infection. Topical, oral or systemic antimicrobial therapy and drainage or debridement could be necessary, along with treatment of a significant underlying disease. This review discusses the epidemiology, the pathogenesis and the classification of bacterial SSTI, describes their associated risk factors and their clinical presentations. The authors provide a rational diagnostic and therapeutic approach to SSTI in respect of antibiotic resistance and currently available antimicrobial agents. PMID:22214317
The present study reports for the first time, the in vivo wound healing potential of Punica granatum L. peels. A 5% (w/w) methanolic extract based-ointment was formulated and evaluated for its wound healing in guinea pigs. The ointment was applied in vivo on the paravertebral area of twelve excised wounded models once a day for 10 consecutive days. The ointment significantly enhanced the wound contraction and the period of epithelialization as assessed by the mechanical (contraction rate, tensile strength), the biochemical (increasing of collagen, DNA and proteins synthesis) and the histopathological characteristics. Such investigation was encouraged by the efficiency of the methanolic extract as antimicrobial and antioxidant. Indeed, the extract showed antioxidant activity as strong as natural and synthetic compounds (Trolox, BHA, Quercetin). Furthermore, the extract exhibited significant antibacterial and antifungal activity against almost all tested bacteria: Pseudomonas aeruginosa ATCC 9027, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Klebsiella pneumoniae, Salmonella anatum, Salmonella typhimurium, Streptococcus pneumoniae, and fungi Candida albicans, Candida glabrata, Trichopyton rubrum and Aspergillus niger. The formulated ointment might well find use as skin repair agent without hazard to human health based on these results and on the fact that it has been well established that the extracts of pomegranate used in conditions similar to those applied by traditional medicine, showed no toxic effects. PMID:21466954
Ceftaroline, the bio-active form of parenterally administered ceftaroline fosamil, is a unique broad-spectrum cephalosporin with in vitro and in vivo activity against methicillin-resistant Staphylococcus aureus and was approved for clinical use by the United States Food and Drug Administration in October 2010. In over a year since ceftaroline fosamil approval, no widely used commercial susceptibility test system has added this new compound to its product, therefore requiring use of alternative agar diffusion methods for clinical microbiology laboratories that want to test clinical isolates for ceftaroline susceptibility. An alternative strategy of applying a surrogate ?-lactam class marker agent was assessed here, using results from 14,902 organisms (2008-2010) sampled in the USA. Very high and acceptable accuracy (?99.75%) was observed for predicting ceftaroline susceptibility as follows: 1) use of imipenem or meropenem minimum inhibitory concentrations (MICs) at ?8 ?g/mL (susceptible and intermediate categories) when testing S. aureus; 2) use of ceftriaxone MIC at ?2 ?g/mL (susceptible and intermediate categories) when testing Streptococcus pneumoniae as well as other streptococci (S. pyogenes and S. agalactiae); and 3) use of ceftriaxone, or cefepime, or ceftazidime at ?2 ?g/mL (susceptible category) when testing Haemophilus influenzae. Only when testing indicated Enterobacteriaceae species using ceftriaxone susceptibility results did the ceftaroline-nonsusceptible errors increase (4.11%). These presented analyses offer a validated surrogate marker strategy for ceftaroline susceptibility testing, pending development and validation by the commonly used automated systems and agar diffusion commercial methods. PMID:23023107
Abstract in portuguese Foram analisados dados do prontuário de 176 pacientes com idade igual ou superior a 15 anos, internados no Hospital Couto Maia, no período de janeiro de 1990 a dezembro de 1992, em Salvador-BA, com o diagnóstico de meningite piogênica. Observamos, em ordem decrescente, maior percentagem de pacientes com N. meningitidis (56,7%), S. pneumoniae (37,5%) e E.coli. (3,3%). A letalidade foi maior no grupo com meningite pneumocócica. No grupo de indivíduos com meningite por (more) pneumococo verificamos que a média etária e de leucócitos no sangue periférico foram superiores quando comparadas com o grupo de portadores de meningite meningocócica. Por outro lado, neste último grupo a média de glicorraquia foi maior. A presença de lesões cutâneas hemorrágicas mostrou-se preditora da etiologia meningocócica. Abstract in english We reviewed the charts of 176 adult patients, admitted with a diagnosis of acute bacterial meningitis, in the Hospital Couto Maia, from January 1990 to December 1992. All the patients had community-acquired meningitis. In 120 patients we could identify the causative agent on Gram's staining and culture. The most common pathogens were N. meningitidis (56.7%) S. pneumoniae (37.5%) and E. coli (3.3%). The overall lethality rate was 19.8% and the lethality was greater in the (more) group with streptococcus meningitis (31.8%). The mean age and the leukocyte in the peripheral blood were greater in the group with S. pneumoniae meningitis than in the meningococal group. Cutaneous hemorrhagic lesions was an excellent predictor meningococcal meningitis.
This study aimed to conduct a pilot evaluation of broad-based multiprobe polymerase chain reaction (PCR) in clinical cerebrospinal fluid (CSF) samples compared to local conventional PCR/culture methods used for bacterial meningitis surveillance. A previously described PCR consisting of initial broad-based detection of Eubacteriales by a universal probe, followed by Gram typing, and pathogen-specific probes was designed targeting variable regions of the 16S rRNA gene. The diagnostic performance of the 16S rRNA assay in "127 CSF samples was evaluated in samples from patients from Togo, Africa, by comparison to conventional PCR/culture methods. Our probes detected Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. Uniprobe sensitivity and specificity versus conventional PCR were 100% and 54.6%, respectively. Sensitivity and specificity of uniprobe versus culture methods were 96.5% and 52.5%, respectively. Gram-typing probes correctly typed 98.8% (82/83) and pathogen-specific probes identified 96.4% (80/83) of the positives. This broad-based PCR algorithm successfully detected and provided species level information for multiple bacterial meningitis agents in clinical samples. PMID:22809694
Abstract in english Most patients with acute suppurative meningitis are otherwise healthy individuals with regard to immune mechanisms against invasive bacterial disease. This medical emergency is among the most dramatic and potentially ravaging diseases that affect humans, particularly young children. The illness often strikes suddenly, and can either result in death or leave the survivors with significant neurological dysfunctions. The demonstration of a bacterial aetiology is necessary fo (more) r decisions regarding treatment and prophylaxis. Conventional bacteriological methods frequently fail to identify an agent, as a result of administration of antibiotics or delayed lumbar punctures. We investigated the major aetiologic sources of unspecified bacterial meningitis cases (G00.9, ISCD-10) by polymerase chain reaction (PCR)-based identification of Neisseria meningitidis (crgA), Streptococcus pneumoniae (ply) and Haemophilus influenzae (bexA) in cerebrospinal fluid samples. The multiplex PCR detected N. meningitidis in 92%, S. pneumoniae in 4% and H. influenzae in 1% of the 192 clinical samples assayed; 3% were negative for all three DNA targets. Bacterial DNA detection was found to be a valuable adjunct to enhance bacterial meningitis surveillance when the yield of specimens by culture is reduced. The implementation of PCR assays as a diagnostic procedure in Public Health Laboratories is perceived to be a significant advance in the investigation of bacterial meningitis.
Abstract in english Diagnosis of bacterial meningitis has long been based on classical methods of Gram stain, serological tests, and culture of cerebrospinal fluid (CSF). The performance of these methods, especially culture and direct smear, is thwarted by failure to detect bacteria following administration of antimicrobial agents and reluctance to performance lumbar punctures at admission. Indeed, patients with meningitis frequently receive antibiotics orally or by injection before the diag (more) nosis is suspected or established. Thus an alternative method has become necessary to help clinicians and epidemiologists to management and control of bacterial meningitis. We evaluate the application of a polymerase chain reaction-based (PCR) assay for amplification of pneumolysin gene (ply) to diagnosis of Streptococcus pneumoniae meningitis. The PCR assay sensitivity for CSF was 96% (95% confidence interval, CI, 90-99%) compared to a sensitivity of 59% for culture (95% CI 49-69%), 66% for Gram stain (95% CI 56-74%), and 78% for latex agglutination test (95% CI 69-86%); PCR specificity was 100% (95% CI 83-100%). PCR results were available within 4 h of the start of the assay. This molecular approach proved to be reliable and useful to identify this bacterium compared with other classical laboratory methods for identification of bacterial meningitis pathogens.
Group B Streptococcus (GBS) capsular type III is an important agent of life-threatening invasive infections. It has been previously shown that encapsulated GBS is easily internalized by dendritic cells (DCs) and can persist inside these immune cells. The mechanisms underlying these processes are unknown. Here, colocalization studies and the use of endocytosis inhibitors and caveolin(-/-) mice, demonstrated that GBS uses multiple endocytosis mechanisms to enter mouse DCs. The capsular polysaccharide (CPS) selectively drives GBS internalization via caveolae-independent but lipid raft-dependent pathways. Non-encapsulated bacteria failed to engage lipid rafts. GBS internalization by DCs also occurs via clathrin-mediated endocytosis in a process independent of bacterial CPS. Albeit caveolae are not required for GBS internalization, signalling events through caveolin-1 are involved in production of the inflammatory chemokine CCL2 by DCs infected with encapsulated GBS only. This study addresses for the first time endocytosis pathways implicated in DC internalization of encapsulated GBS and suggests a complex interplay between GBS and DCs, which was selectively modulated by the presence of CPS. PMID:22735044
Prulifloxacin, the prodrug of ulifloxacin, is a broad-spectrum oral fluoroquinolone antibacterial agent. After absorption, prulifloxacin is metabolised by esterases to ulifloxacin. The drug has a long elimination half-life, allowing once-daily administration. Ulifloxacin is generally more active in vitro than other fluoroquinolones against a variety of clinical isolates of Gram-negative bacteria, including community and nosocomial isolates of Escherichia coli, Klebsiella spp., Proteus, Providencia and Morganella spp., Moraxella catarrhalis and Haemophilus spp. The activity of ulifloxacin against Pseudomonas aeruginosa varies between countries. Gram-positive organisms, including meticillin- or oxacillin-susceptible Staphylococcus aureus, Enterococcus spp. and Italian community isolates of Streptococcus pneumoniae are susceptible to ulifloxacin. Activity against Spanish strains of S. pneumoniae is moderate. In well designed clinical trials, good clinical and bacteriological efficacy (similar to that of ciprofloxacin, amoxicillin/clavulanic acid or pefloxacin) was seen with prulifloxacin 600 mg once daily for 10 days in patients with acute exacerbations of chronic bronchitis or complicated lower urinary tract infections (UTIs), and with single-dose prulifloxacin 600 mg in acute, uncomplicated lower UTIs. Prulifloxacin was generally well tolerated in clinical trials, with a similar tolerability profile to that of ciprofloxacin. PMID:15456336
Regulation of transcription by SMU.1349, a TetR family regulator, in Streptococcus mutans.
The TetR family of transcriptional regulators is ubiquitous in bacteria, where it plays an important role in bacterial gene expression. Streptococcus mutans, a gram-positive pathogen considered to be the primary etiological agent in the formation of dental caries, encodes at least 18 TetR regulators. Here we characterized one such TetR regulator, SMU.1349, encoded by the TnSmu2 operon, which appeared to be acquired by the organism via horizontal gene transfer. SMU.1349 is transcribed divergently from the rest of the genes encoded by the operon. By the use of a transcriptional reporter system and semiquantitative reverse transcription-PCR (RT-PCR), we demonstrated that SMU.1349 activates the transcription of several genes that are encoded within the TnSmu2 operon. Gel mobility shift and DNase I footprinting assays with purified SMU.1349 protein demonstrated binding to the intergenic region between SMU.1349 and the TnSmu2 operon; therefore, SMU.1349 is directly involved in gene transcription. Using purified S. mutans RpoD and Escherichia coli RNA polymerase, we also demonstrated in an in vitro transcription assay that SMU.1349 could activate transcription from the TnSmu2 operon promoter. Furthermore, we showed that SMU.1349 could also repress transcription from its own promoter by binding to the intergenic region, suggesting that SMU.1349 acts as both an activator and a repressor. Thus, unlike most of the TetR family proteins, which generally function as transcriptional repressors, SMU.1349 is unique in that it can function as both. PMID:21965566
Isolation of a variant of Streptococcus faecalis with enhanced barotolerance.
Streptococcus faecalis ATCC 9790 was adapted to grow at pressures as high as 1000 atm (1 atm = 101.325 kPa) at 37 degrees C by gradually increasing the growth pressure for agar stab subcultures in steps of 50 atm from 750 atm, the maximum growth pressure for unadapted cultures. A stable variant with enhanced barotolerance designated APR-11 was characterized. Similar variants could be obtained repeatedly from S. faecalis cultures by following the indicated procedure, APR-11 was able to grow in liquid media at pressures some 200 atm greater than the maximum for the parent. It appeared to have a regulatory defect in the arginine dihydrolase system and produced ammonia during glycolysis even in the presence of high concentrations of glucose. The ammonia acted to neutralize metabolic acids and to confer a type of acid tolerance. This acid tolerance may be involved in barotolerance since pressure is known to render S. faecalis hypersensitive to acid conditions. In all, it appeared that pressure can be used as a selection agent for isolation of rare barotolerant variants in normal bacterial populations. PMID:6773652
Trial Watch: Experimental Toll-like receptor agonists for cancer therapy.
Toll-like receptors (TLRs) are prototypic pattern recognition receptors (PRRs) best known for their ability to activate the innate immune system in response to conserved microbial components such as lipopolysaccharide and double-stranded RNA. Accumulating evidence indicates that the function of TLRs is not restricted to the elicitation of innate immune responses against invading pathogens. TLRs have indeed been shown to participate in tissue repair and injury-induced regeneration as well as in adaptive immune responses against cancer. In particular, TLR4 signaling appears to be required for the efficient processing and cross-presentation of cell-associated tumor antigens by dendritic cells, which de facto underlie optimal therapeutic responses to some anticancer drugs. Thus, TLRs constitute prominent therapeutic targets for the activation/intensification of anticancer immune responses. In line with this notion, long-used preparations such as the Coley toxin (a mixture of killed Streptococcus pyogenes and Serratia marcescens bacteria) and the bacillus Calmette-Guérin (BCG, an attenuated strain of Mycobacterium bovis originally developed as a vaccine against tuberculosis), both of which have been associated with consistent anticancer responses, potently activate TLR2 and TLR4 signaling. Today, besides BCG, only one TLR agonist is FDA-approved for therapeutic use in cancer patients: imiquimod. In this Trial Watch, we will briefly present the role of TLRs in innate and cognate immunity and discuss the progress of clinical studies evaluating the safety and efficacy of experimental TLR agonists as immunostimulatory agents for oncological indications. PMID:22934262
Development of a collection of bacteria causing meningitis in Rio de Janeiro from 1990 to 1991
Abstract in english From March 1990 to December 1992, the National Institute for Quality Control of Health-INCQS Research Collection received 1476 bacterial samples isolated from human cerebrospinal fluid of patients suspect of meningitis in Rio de Janeiro, from the São Sebastião State Institute of Infectious Diseases (IEISS). Neisseria meningitidis was found in most of these materials, followed in smaller number by Haemophilus sp. and Streptococcus pneumoniae. The great majority of N. men (more) ingitidis strains was serogroup B, followed by serogroup C and a few strains of serogroup W135. More than 50 of the isolated bacterial agents came from the predominant 0-4 years age group. The majority of the strains were from patients in the region known as "Baixada Fluminense" (Low Lands). The aim of the work presented here is to obtain samples of meningitis cases in at least 70 of the State of Rio de Janeiro and develop a collaborative research between INCQS-FIOCRUZ and the IEISS, in order to set up a collection of strains for future studies. However, despite work being carried out in a rather satisfactory way, difficulties still arise and have to be overcome, to survey data.
Combat pneumococcal infections: adhesins as candidates for protein- based vaccine development.
Streptococcus pneumoniae (pneumococcus) is an asymptomatic colonizer of the upper respiratory tract in humans. However, these apparently harmless bacteria have also a high virulence potential and are known as the etiologic agent of respiratory and life-threatening invasive diseases. Dissemination of pneumococci from the nasopharynx into the lungs or bloodstream leads to community-acquired pneumonia, septicaemia and meningitis. Traditionally, pneumococcal diseases are treated with antibiotics and prevented with polysaccharide-based vaccines. However, due to the dramatic increase in antibiotic resistance and limitations of the current available vaccines, the burden of diseases remains high. Thus, combating pneumococcal transmission and infections has emphasized the need for a new generation of protein-based vaccines. Interactions of pneumococci with soluble host proteins or cellular receptors are crucial for adherence, colonization, transmigration of host barriers and immune evasion. Therefore, surface-exposed proteins involved in these pathogenic processes and virtually expressed by all pneumococcal strains and serotypes are the prime potential targets for an immunogenic and highly protective pneumococcal-derived carrier protein of a vaccine. In this review, we will address the state of the art in deciphering, i). the conservation, distribution and pathogenic role of recently discovered pneumococcal adhesins in colonization and invasive diseases, ii). the interactions of these virulence factors with host-proteins and receptors, iii). the subversion of the host immune and cellular responses, and iv). the potential of pneumococcal adhesins as vaccine candidates. PMID:22206255
In a prospective study of rhinosinusitis treatment efficacy in 163 subjects at 30 medical facilities between 2008 and 2009, we studied isolation of three major pathogenic bacteria-Streptococcus pneumoniae, Haemophillus influenzae, and Moraxella catarrhalis. We also examined clinical garenoxacin (GRNX) efficacy in 106 acute rhinosinusitis cases and 57 acute chronic rhinosinusitis exacerbation cases using Japan Acute Rhinosinusitis Clinical Guideline 2010 clinical scoring. Isolation of S. pneumoniae was 50.0% (22/44), H. influenzae 43.2% (19/44), and M. catarrhalis 6.8% (3/44) in 106 acute rhinosinusitis subjects. Drug-resistant strains accounted for over 50% in S. pneumoniae and H. influenzae. Isolation of the three bacterial pathogens in 57 acute chronic rhinosinusitis exacerbation subjects was 50.0% (9/18) in S. pneumoniae, 27.8% (5/18) in H. influenzae, and 22.2% (4/18) in M. catarrhalis. Drug resistance exceeded 40% in S. pneumoniae and H. influenzae. In efficacy studies of 97 subjects, GRNX at 400 mg/day in 54 with acute rhinosinusitis was 100%—marked improvement in 51.9% (28/54) and moderate in 48.1% (26/54). Efficacy in 43 acute chronic rhinosinusitis exacerbation subjects was 95.3%—marked improvement in 79.1% (34/43) and moderate in 16.3% (7/43). These results show the usefulness of clinical scoring in diagnosing diseases severity and in studying the efficacy of antimicrobial agents. Data clearly indicated the high clinical and bacterial efficacy of garenoxacin in treating adult rhinosinusitis.
[Cancer, febrile neutropenia and pulmonary images: Findings in bronchoalveolar lavage in children].
Introduction: Lung infections are a serious complication in children with cancer. Bronchoalveolar lavage (BAL) has been demonstrated to be an effective procedure for achieving etiologic diagnosis. Method: We did a retrospective analysis of BAL data performed between November 2005 and October 2008 in children with cancer, severe neutropenia and lung infiltrates for assessing its performance, clinical utility and safety. Thirty-seven BAL were evaluated in 35 patients. Results: Focal infiltrates were demonstrated in imaging studies associated with 19/37 BAL; in 8 an infectious agent was found. Interstitial pattern was observed in 15/37, in which there were 4 positive studies, proving a higher microbiological performance in BAL associated with focal lesions. BAL yielded significant microbiological findings in 32.4% (12/37). Sixteen microorganisms were identified in the study: bacteria in 8 cases, Mycobacterium tuberculosis (n: 2), Pseudomonas aeruginosa (n: 2), Acinetobacter baumannii (n: 1), A. Iwoffii (n: 1), group viridans Streptococcus (n: 1), Mycoplasma pneumoniae (n: 1); viruses in 3 cases, metapneumovirus (n: 2) cytomegalovirus (n: 1) and fungal infection in 5 cases, Pneumocystis jiroveci (n: 2) Aspergillus fumigatus (n: 1), Aspergillus niger (n: 1), Candida albicans (n: 1). Therapeutic adjustments were done in 6/37 episodes (16.2%). Conclusion: BAL has a significant role in the evaluation of pulmonary infiltrates in pediatric oncological patients, requiring a prompt and safe diagnosis, which is crucial for the survival with minimal morbidity. Our results suggest that BAL by fiberbronchoscopy should be considered as an initial diagnostic tool in these patients. PMID:23096474
In vitro antifungal activities of longan (Dimocarpus longan Lour.) seed extract.
Longan, Dimocarpus longan Lour., contains polyphenolic compounds which exhibit several pharmacological properties. This study aims to evaluate antifungal activities of longan fruit extract in comparison to its active compounds. The results showed that longan seed exhibited antifungal activity against the opportunistic yeasts (Candida species and Cryptococcus neoformans). In contrast, longan pulp and whole fruit did not demonstrate any inhibitory effects. Ellagic acid showed the most potent antifungal activity followed by corilagin and gallic acid, respectively. Ellagic acid inhibited Candida parapsilosis and C. neoformans more effectively than Candida krusei and also some Candida albicans clinical strains. Baidam cultivar possessed higher antifungal activity (MIC=500-4000 ?g/ml) as it contained higher contents of ellagic acid and gallic acid than Edor (MIC=1000-8000 ?g/ml). For antibacterial activity, only corilagin and gallic acid possessed weak to moderate inhibitory effects against Staphylococcus aureus and Streptococcus mutans, respectively. Longan seed was then applied in the oral care products. Longan effervescent granule (5% extract) significantly reduced adhesion of C. albicans to acrylic strips. Mouthwash containing 0.5% extract exhibited good antifungal activity compared to a commercial product. These findings indicated that longan seed extract and its polyphenolic compounds can be used as an antifungal agent in oral care products for the treatment of opportunistic yeast infection. PMID:22245574
Sixty-seven crude ethanol extracts from 50 plants (31 families), which are used in North Côte-d'Ivoire as traditional remedies for bacterial diseases, were screened for in vitro activity against Gram negative (Escherichia coli and Pseudomonas aeruginosa) and Gram positive (Staphylococcus aureus, Enterococcus faecalis, Streptococcus pyogenes and Bacillus subtilis) bacteria. Thirty-one extracts showed antibacterial activity only on Gram positive bacteria. Of these, 10 extracts from 10 plant species had a promising level of activity against bacteria including strains resistant to antibiotics such as aminosides, penicillin M, macrolides, lincosamide and streptrogramin B. The most active was Erythrina senegalensis DC (Fabaceae) followed by Bobgunnia madagascariensis (Desv.) J.H. Kirkbr. & Wiersema (Caesalpinaceae), Waltheria lanceolata R. Br. ex Mast. (Sterculiaceae), Uapaca togoensis Pax. (Euphorbiaceae), Ximenia americana L. (Olacaceae), Khaya senegalensis (Ders.) A. Juss. (Meliaceae), Lannea acida A. Rich. (Anacardiaceae), Cissus populnea Guill. & Perr. (Vitaceae), Keetia hispida (Benth.) Bridson (Rubiaceae) and Ficus thonningii (Miq.) A. Rich. (Moraceae). This is the first report of the antibacterial potency of these 10 plant species on a range of bacteria. The results provided evidence that some of the studied plants might indeed be potential sources of new antibacterial agents, also against some antibiotic-resistant strains. PMID:15182903
Abstract in english Background: Streptococcus pneumoniae is a common etiologic agent of invasive respiratory infections among children under 5 years of age and older adults. Isolation rates of S. pneumoniae by traditional culture techniques are low. Aim: To study the sensitivity and specificity of two different DNA extraction methods to amplify the ply gene, applied to three different types of blood culture broths, experimentally inoculated with S. pneumoniae. Material and methods: DNA was e (more) xtracted from the cultures using an organic method or a technique that consists in dilution, washing with NaOH and concentration of the sample. This was followed by PCR amplification of a 355 pb fragment of the pneumolysin gene (ply). Results: The organic DNA extraction method inhibited the PCR reaction at all concetrations studied (0.6 to 10(6) colony forming units/mL). Using the NaOH extraction, ply gene amplification was positive in all three blood culture broths, but only at concentrations of 10³ colony forming units/mL or higher. Using the same DNA extraction method, PCR was negative when the broths were inoculated with seven other related bacterial species, which results in a 100% specificity. Conclusions: Detection of S. pneumoniae by amplification of ply gene from blood cultures using the protocol of NaOH for DNA extraction is specific and provides results in a short lapse. However, the diagnostic sensitivity is not optimal, wich limits its clinical use (Rev Méd Chile 2004; 132: 533-8).
Ultraviolet radiation for the sterilization of contact lenses
Two sources of ultraviolet (UV) radiation with peak wavelengths in the UV-C or UV-B ranges were compared for their ability to sterilize contact lenses infected with Pseudomonas aeruginosa, Streptococcus pneumoniae, Acanthamoeba castellani, Candida albicans, and Aspergillus niger. Also examined was the effect of prolonged UV light exposure on soft and rigid gas permeable (RGP) contact lenses. The UV-C lamp (253.7 nm, 250 mW/cm2 at 1 cm) was germicidal for all organisms within 20 minutes but caused destruction of the soft lens polymers within 6 hours of cumulative exposure. UV-C caused damage to RGP lenses in less than 100 hours. The UV-B lamp (290-310 nm, 500 mW/cm2 at 1 cm) was germicidal for all organisms tested (except Aspergillus) with a 180-minute exposure and caused less severe changes in the soft lens polymers than did the UV-C lamp, although cumulative exposure of 300 hours did substantially weaken the soft lens material. RGP materials were minimally affected by exposure to 300 hours of UV-B. Ultraviolet light is an effective germicidal agent but is injurious to soft lens polymers; its possible utility in the sterilization of RGP lenses and lens cases deserves further study.
Current progress with Moraxella catarrhalis antigens as vaccine candidates.
The success of the immunization programs against Haemophilus influenzae type b and, more recently, Streptococcus pneumoniae in developed and some developing countries has demonstrated that invasive disease caused by these bacteria can be very effectively controlled by vaccination. There is also evidence that pneumococcal vaccines can reduce the incidence of acute otitis media in children. More complete control of this disease would be achieved if infections caused by Moraxella catarrhalis and nontypeable H. influenzae, the other common agents of otitis media in children and of a number of respiratory-associated infections in both children and adults, could also be controlled. Since these bacteria do not possess capsules and are not known to secrete exotoxins, the search for vaccine candidates has focused on the conserved epitopes exposed on the bacterial outer membrane. In this article, we review the contribution of M. catarrhalis to disease and recent advances in the development and testing of various vaccine candidates against this bacterium, including those still in the development stage and those approaching clinical trials. Recommendations are proposed for approaches needed for the standardization of assays and use of appropriate animal models for quality-control testing of these vaccine candidates. Regulatory issues surrounding vaccines of this type are also discussed. PMID:19093775
High burden of antimicrobial resistance in Asia.
Antimicrobial resistance is associated with high mortality rates and high medical costs. Marked variations in the resistance profiles of bacterial and fungal pathogens as well as the quality of public hygiene have had a considerable impact on the effectiveness of antimicrobial agents in Asian countries. In Asia, one of the epicentres of antimicrobial drug resistance, there is an alarming number of antibiotic-resistant species, including penicillin- and erythromycin-resistant Streptococcus pneumoniae, ampicillin-resistant Haemophilus influenzae, multidrug-resistant (MDR) Acinetobacter baumannii, extended-spectrum ?-lactamase (ESBL)-producing Klebsiella pneumoniae (particularly mediated by CTX-M-9, CTX-M-14 and CTX-M-15), New Delhi metallo-?-lactamase 1 (NDM-1)-producing Enterobacteriaceae, MDR Salmonella enterica serotypes Choleraesuis and Typhi, carbapenem-resistant A. baumannii (OXA-58 and OXA-23 carbapenemases) and azole-resistant Candida glabrata. A few clones of MDR A. baumannii and hospital-acquired meticillin-resistant Staphylococcus aureus (MRSA) have been widely disseminated in hospital settings in Asia, and K. pneumoniae carbapenemase (KPC)-producing K. pneumoniae strains have been widely distributed in China. In addition, the emergence of extensively drug-resistant Mycobacterium tuberculosis (XDR-TB) has illustrated the need for regular monitoring of resistance profiles of clinical isolates as well as the deliberative use of fluoroquinolones. Continuous surveillance of resistance data from clinical isolates as well as implementation of strict infection control policies in healthcare settings are required to mitigate the progression of antimicrobial resistance. PMID:21382699
Streptococcus suis is a major pathogen of swine, causing mainly meningitis, and it also represents an emerging zoonotic agent. We investigated its ability to induce the release of pro-inflammatory cytokines and chemokines by porcine brain microvascular endothelial cells (PBMEC). We demonstrated that live S. suis induced a strong release of interleukin (IL)-6 and IL-8 by PBMEC. We showed that the suilysin (hemolysin) was largely responsible for such stimulation, although cell wall components also contribute to cell stimulation but to a considerably lower extent. Interestingly, IL-8 production by PBMEC became undetectable by increasing either the incubation time or bacterial concentration of certain live S. suis strains. We further demonstrated that this decrease of IL-8 levels was probably linked to the production of a serine protease by S. suis. Our results suggest that S. suis can induce an exacerbated release of inflammatory mediators by swine endothelial cells that could cause a massive recruitment of leukocytes and subsequent blood-brain barrier breakdown facilitating the pathogenesis of S. suis-induced meningitis. In addition, S. suis could modulate this response by degrading IL-8 which might delay recruitment of S. suis killer-neutrophils to the site of inflammation, allowing this pathogen to survive upon its arrival to central nervous system. PMID:19100324
Progress towards meningitis prevention in the conjugate vaccines era
Abstract in english Acute bacterial meningitis is an important cause of morbidity and mortality among children less than five years old. Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis are the most important agents of bacterial meningitis in developing countries. The development of the conjugate vaccines in the beginning of the 90's, especially type b H. influenzae (Hib), and more recently the heptavalent pneumococcal and the serogroup C meningococcal vaccines, ha (more) ve contributed directly to changes in the epidemiological profile of these invasive diseases (direct effect) and of their carriage status (indirect effect). We review the impact of the Hib conjugate vaccine in Latin American countries, where this vaccine has been implemented, and the potential of pneumococcal and meningococcal conjugate vaccines for the reduction of meningitis worldwide. We also address constraints for the development and delivery of these vaccines and review new candidate state-of-the-art vaccines. The greatest challenge, undoubtedly, is to implement these vaccines worldwide, especially in the developing regions.
OBJECTIVES: Modifications of titanium (Ti) implant surfaces have a significant effect on early biofilm formation and the outcome of implant procedures. The aim of this study was to examine the role of plasma proteins and electrostatic forces in the adhesion mechanism of oral bacteria to modified Ti surfaces. MATERIALS AND METHODS: Ti discs with three different types of surface modifications, machined, acid-etched, and acid-etched and blasted, were examined for adhesion of oral bacteria: Streptococcus mutans, Porphyromonas gingivalis, and Fusobacterium nucleatum. Following pretreatment of the Ti with ion rich solutions or coating by human serum albumin or fibronectin, bacterial adhesion was examined by scanning electron microscopy and assessed quantitatively by DNA analysis. Ti coating by proteins as well as bacterial adhesion and their interrelationships were further investigated through confocal scanning laser microscopy. RESULTS: Acid-etched and blasted Ti surfaces exhibited significantly higher amounts of bacteria adhesion than the other two surfaces. Calcium was found to serve as a bridging agent in the adhesion process of S. mutans and F. nucleatum to Ti surfaces. Although albumin coating of the Ti reduced the adhesion of S. mutans to all surfaces, it had no influence on the adhesion of P. gingivalis or F. nucleatum. Coating the Ti with fibronectin enhanced P. gingivalis and F. nucleatum adhesion. CONCLUSIONS: Bacterial adhesion to Ti surfaces is roughness-dependent, and the adhesion mechanism is influenced by ions and proteins of the initial coating derived from the blood. PMID:22150723
AIM: To assess inter-observer variation in the interpretation of chest radiographs of individuals with pneumonia versus those without pneumonia. MATERIALS AND METHODS: Chest radiographs of out-patients with a lower respiratory tract infection (LRTI) were assessed for the presence of infiltrates by radiologists from three local hospitals and were reassessed by one university hospital radiologist. Various measures of inter-observer agreement were calculated. RESULTS: The observed proportional agreement was 218 in 243 patients (89.7%). Kappa was 0.53 (moderate agreement) with a 95% confidence interval of 0.37 to 0.69. The observed positive agreement (59%) was much lower than for negative agreement (94%). Kappa was considerably lower, if chronic obstructive pulmonary disease was present ({kappa}=0.20) or Streptococcus pneumoniae ({kappa}=-0.29) was the infective agent. CONCLUSION: The overall inter-observer agreement adjusted for chance was moderate. Inter-observer agreement in cases with pneumonia was much worse than the agreement in negative (i.e. non-pneumonia) cases. A general practitioner's selection of patients with a higher chance of having pneumonia for chest radiography would thus not improve the observer agreement.
The aim of this study was to test the antibacterial effects of three experimental quaternary ammonium salt monomers in order to evaluate their potential applications as dental materials. In vitro susceptibility testing of the monomers was performed by the broth dilution method on bacteria associated with oral infections: Streptococcus mutans ATCC 25175, Actinomyces viscosus ATCC 15987, Staphylococcus aureus ATCC 29213 and Lactobacillus casei ATCC 393. The time-kill kinetics of the monomer with relatively higher antibacterial activity against S. mutans were also investigated. It was found that all the tested bacteria strains were susceptible to the three monomers, among which methacryloxylethyl cetyl ammonium chloride (DMAE-CB) exhibited the lowest minimal inhibitory concentrations, ranging from 1.2 to 4.8 ?g/ml. The time-kill curve showed that DMAE-CB achieved 99.44% killing at 19.2 ?g/ml (4 times the minimal bactericidal concentration) against S. mutans after 1 min and 100% killing within 10 min of contact. This result indicates that the quaternary ammonium salt monomer DMAE-CB may be a candidate antibacterial agent for incorporation into dental restorative materials. (J. Oral Sci. 50, 323-327, 2008)
Pneumolysin (PLY) is a key virulence factor contributes to the pathogenesis of Streptococcus pneumoniae. In this study we investigated the effect of allicin and aqueous garlic extracts on hemolytic activity of PLY both in prelysed and intact cells. Additionally the antimicrobial activity of allicin was tested against the bacteria. All tested materials potently inhibited the PLY hemolytic activity. Allicin neutralizes PLY in a concentration- and time-dependent manner. Twenty five minute incubation of PLY (2 HU/mL) with 0.61 ?M/mL concentration of allicin, totally inhibited hemolytic activity of PLY (IC50 = 0.28 ?M/mL). The inhibitory activity of old extract of garlic was similar to pure allicin (IC50 = 50.46 ?L/mL; 0.31 ?M/mL; P allicin). Exposure of intact cells to allicin (1.8 ?M) completely inhibited hemolytic activity of PLY inside bacterial cells. The inhibitory effect of the allicin was restored by addition of reducing agent DTT at 5 mM, proposing that allicin likely inhibits the PLY by binding to cysteinyl residue in the binding site. The MIC value of allicin was determined to be 512 ?g/mL (3.15 ?M/mL). These results indicate that PLY is a novel target for allicin and may provide a new line of investigation on pneumococcal diseases in the future. PMID:21184771
Evaluation of genotypic diversity of Streptococcus mutans using distinct arbitrary primers.
Streptococcus mutans has been considered one of the main etiological agents of dental caries and the genotypic diversity rather than its salivary counts may be considered as a virulence factor of this bacterium. For genotyping with polymerase chain reaction (PCR) with arbitrary primers, several primers have been used in order to improve complexity and specificity of amplicon patterns. Thus, the aim of this study was to evaluate the degree of agreement of genotypic identification among AP-PCR reactions performed with 5 distinct arbitrary primers of S. mutans isolated from saliva. Stimulated saliva was collected from 11 adult volunteers for isolation of S. mutans, and a total of 88 isolates were genotyped with arbitrary primers OPA 02, 03, 05, 13 and 18. Fourteen distinct genotypes were identified in the saliva samples. Most volunteers (9 out of 11) presented only one genotype. The results of the present study suggest that primers OPA 02, 03, 05 and 13 were suitable for genotypic identification of S. mutans isolates of saliva from adult volunteers. PMID:19082399
Three new flavonoid glycosides, named chalcone-6'-hydroxy-2',3,4-trimethoxy-4'-O-beta-D-glucopyranoside (1), isoflavone-3',4',5,6-tetrahydroxy-7-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranoside] (2), and isoflavone-3',4',5,6-tetrahydroxy-7-O-[beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranoside] (3), were isolated from the leaves of Boehmeria rugulosa, together with five known compounds, beta-sitosterol, quercetin, 3,4-dimethoxy-omega-(2'-piperidyl)-acetophenone (4), boehmeriasin A (5), and quercetin-7-O-beta-D-glucopyranoside. The structures of the isolated compounds were determined by means of chemical and spectral data including 2D NMR experiments. The ethanolic extract of leaves showed significant hypoglycemic activity on alloxan-induced diabetic mice. Glibenclamide, an oral hypoglycemic agent (5 mg/kg, p.o.), was used as a positive control. The ethanolic extract of the plant as well as the isolated compounds 1-3 (25 microg/ml) showed potent antimicrobial activity against two bacterial species (Staphylococcus aureus and Streptococcus mutans) and three fungus pathogens (Microsporum gypseum, Microsporum canis, and Trichophyton rubrum). The activities of the isolated compounds 1-3 have been compared with positive controls, novobiocin, and erythromycin (15 microg/ml). PMID:20183275
Abstract in portuguese No período de abril de 1979 a julho de 1980 foram estudadas 45 crianças, de ambos os sexos, na faixa etária de 2 meses a 5 anos de idade, selecionadas entre as atendidas no Instituto da Criança "Pedro Alcântara" do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, e acometidas de pneumopatias agudas. Dos 45 pacientes estudados, a maioria (46,7%) encontrava se na faixa de 2-12 meses de idade e, quanto ao estado nutricional, 42,2% eutrófic (more) os e 57,8% desnutridos, variando essa desnutrição do grau I ao grau III. Empregando amostras obtidas por aspiração pulmonar e examinando-as pelo método de coloração de Gram e cultura, foi possível identificar o agente etiológico de 26 (57,7%) pneumonias bacterianas nos 45 casos estudados. A identificação direta pelo método de Gram mostrou-se útil como orientação inicial para antibioticoterapia em 44,4% dos casos. Houve nítida predominância do Streptococcus pneumoniae como agente etiológico bacteriano nas pneumopatias agudas da criança nas várias faixas etárias estudadas seguido do Haemophilus influenzae e o Staphylococcus aureus. O estudo comparativo da cultura do aspirado pulmonar e da hemocultura permitiu maior precisão diagnostica (56,7%), revelando-se a hemocultura positiva em apenas 30,0% dos casos. Não foi constatada nenhuma participação de germes anaeróbios nas pneumopatias da amostragem estudada. Abstract in english Study of acute infant lung infections through transthoracic pulmonary aspiration. In the period of April 1979 to July 1980 were studied 45 children of both sexes aged from 2 months to 5 years, selected from patients at the "INSTITUTO DA CRIANÇA DO HOSPITAL DAS CLÍNICAS" of the, "FACULDADE DE MEDICINA DA UNIVERSIDADE DE SÃO PAULO", and suffering from a acute lung infection. Of the 45 patients studied, the majority (46.7%) were in the age group of 2 to 12 months and, in (more) terms of nutritional conditions, 42.2% were in eutrophic condition and 57.8% were undernourished, with this malnutrition varying from first to third degree. By using samples obtained through pulmonary aspiration and examining them through Gram staining and culture, it was possible to identify the etiological agent in 26 (57.8%) bacillary pneumonias of the 45 cases studied. Direct identification by the Gram staining method proved useful for initial orientation of antibiotic therapy in 44 4% of the cases. There was a distinct predominance of Streptococcus pneumoniae as the bacillary etiological agent in the acute infant lung infections of the various age groups studied, followed by Haemophilus influenzae and Staphylococcus aureus. The comparative study of cultures of pulmonary aspirate and hemocultures permitted greater diagnostic precision (56.7%), demonstrating a positive hemoculture in only 30.0% of the cases. There was no evidence of participation by anaerobic germs in the lung infections of the samples estudied.
Abstract in portuguese Neste trabalho, foi estudada a ocorrência e a bacteriologia das otites purulentas em suínos apresentando três condições clínico-patológicas distintas: síndrome multissistêmica do definhamento dos suínos (SMDS), crescimento retardado (porém sem apresentação de sinais clínicos da SMDS) e crescimento normal. No total, foram examinados 385 animais com idade de 60-130 dias, sendo a confirmação do diagnóstico da SMDS obtida pelos sinais clínicos e achados pato (more) lógicos e pela detecção de antígenos virais por imunoistoquímica. De 242 animais com a SMDS, 57 (23,5%) apresentaram lesões purulentas no ouvido médio. Entre os 119 animais de baixo desenvolvimento, apenas 1 (0,7%) apresentou a lesão. Não foram detectadas lesões macroscópicas no ouvido médio dos 24 animais com crescimento normal. Os agentes isolados com maior freqüência foram Arcanobacterium pyogenes (43%), Streptococcus ?-hemolíticos (37,2%) e Pasteurella multocida (27,9%) dos 86 ouvidos submetidos à bacteriologia. A alta ocorrência de lesões purulentas no ouvido médio de animais com a SMDS sugere que a infecção pelo PCV2 pode tornar o suíno mais suscetível às otites bacterianas. A ocorrência reduzida dessas lesões em suínos de baixo desenvolvimento, sem a manifestação clínica da SMDS, sugere que a otite média não representa uma causa importante de mau desempenho em leitões nas fases de crescimento e terminação. O envolvimento de A. pyogenes, Streptococcus ?-hemolíticos e P. multocida na maioria das lesões apontam a importância desses organismos como agentes causais de otite média em suínos. Abstract in english The occurrence and bacteriology of purulent otitis in groups of pigs affected by three different clinical conditions are described: postweaning multisystemic wasting syndrome (PMWS), depressed growth (attrition) and normal growth (control). A total of 385 animals, 60-130 days of age, were examined. Diagnosis of PMWS was confirmed by the presence of clinical signs and pathological findings compatible with the disease, and through detection of viral antigens in tissues by i (more) mmunohistochemistry. From 242 pigs with PMWS, 57 (23.5%) showed purulent lesions in the middle ear. Among 119 pigs with attrition, only 1 (0.7%) presented the lesion. In 24 control pigs, middle ear lesions were not detected. The most frequently isolated agents from the lesions were Arcanobacterium pyogenes (43%), á-hemolytic Streptococci (37.2%) and Pasteurella multocida (27.9 %) out of 86 materials. The frequent occurrence of purulent lesions in the middle ear of PMWS affected pigs suggests that PCV2 infection may increase the susceptibility to bacterial otitis. The low occurrence of this disease in piglets with attrition suggests that otitis does not represent a significant cause for depressed growth in pigs from growing and finishing age. The isolation of A. pyogenes, á-hemolytic Streptococci and P. multocida from most of the lesions emphasizes the importance of these organisms as causal agents of otitis media in swine.
Espondilodiscitis: Análisis de una serie de 25 casos/ Spondylodiscitis, analysis of 25 cases
Abstract in english Background: Spondylodiscitis is a rare but prolonged inflammation of two adjacent vertebral bodies and the disk in between. Aim: To report the clinical features of a series of patients with spondylodiscitis. Material and methods: A retrospective analysis of medical records of patients with spondylitis, identified between 1989 and 2002. Results: A total of 25 cases were identified, 15 female, aged 49.8 years as a mean. Their mean evolution before admission was 4.3 months. (more) Main complaints were back or radicular pain. Mild anemia was present in most patients. Mean erythrocyte sedimentation rate and C reactive protein values were 66 mm/h and 60 mg/L, respectively. Forty four percent of patients had neurological complications. Vertebral computed tomography and scintigraphic studies were done in 72% of patients, but magnetic resonance imaging was done only in 4 (16%). In 18 patients, a tissue sample for pathological and microbiological analysis, was obtained by imaging guiding or surgically. Tuberculosis, diagnosed on pathology, was the leading cause of spondylitis in nine cases (36%), followed by Staphylococcus aureus infection in five (20%). Other agents found were E coli and group D Streptococcus (one each). Age, symptoms, evolution time and different laboratory parameters did not differ between patients with tuberculosis and patients with other causes. A microbiological cause was not established in 36% of cases. Most patients evolved satisfactorily and recovered from neurological complications (88%). One patient with tuberculosis did not improve after prolonged treatment and 2 patients infected with S aureus died (8%). Conclusions: Spondylodiscitis is associated to a diversity of microbial agents and in most cases has a favorable prognosis (Rev Méd Chile 2003; 131: 473-82).
The antibacterial effects of tumescent liposuction fluid.
Tumescent liposuction is currently one of the most commonly performed aesthetic procedures. Despite the variable use of preoperative antibiotics, infection is uncommon. Prior works suggest that the low incidence of infection may be due to lidocaine's antibacterial properties. However, these properties have only been demonstrated using concentrations of lidocaine above 0.8%, significantly higher than those used in tumescent liposuction. The purpose of this study was to determine if the commonly used tumescent fluid containing 0.1% lidocaine, 1:1000,000 epinephrine, and 0.012 mEq sodium bicarbonate possesses antibacterial activity. Using the broth microdilution method, the minimum inhibitory concentrations of Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, and Group A beta-hemolytic Streptococcus were determined after exposure to either lidocaine, epinephrine, bicarbonate, or the combination of all three agents. To determine if there were significant growth differences not detectable by the broth microdilution method, bacterial concentrations were obtained through the use of a spectrophotometer, and significant differences from the controls were calculated by one-way analysis of variance. To determine if prolonged exposure to the tumescent mix would alter bacterial growth, a Killing Time study was also undertaken. The results indicated that the minimum inhibitory concentration of lidocaine was not less than 0.5% for any of the bacteria, whereas the lowest minimum inhibitory concentration of the combined solution was 0.25%. The lowest inhibitory concentration as determined by spectrophotometric analysis for the combined solution was 0.13% (p lidocaine, epinephrine, and bicarbonate do exhibit antibacterial properties at high concentrations. However, the commonly used tumescent mixture containing dilute concentrations of these agents does not significantly inhibit the growth of commonly encountered bacteria. PMID:9950558
Summary of ceftaroline fosamil clinical trial studies and clinical safety.
In October 2010, the new cephalosporin, ceftaroline fosamil, was approved by the US Food and Drug Administration for therapy of community-acquired bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSIs). The active metabolite, ceftaroline, demonstrates in vitro activity against typical bacterial pathogens most often associated with CABP or ABSSSIs, including resistant Gram-positive pathogens such as multidrug-resistant Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus. The efficacy and safety of ceftaroline fosamil was assessed in 2 large phase 3 programs of randomized, double-blind, clinical trials for CABP and ABSSSIs. For both indications, therapy with ceftaroline fosamil was observed to be noninferior to the comparator agents (ceftriaxone for CABP and vancomycin plus aztreonam for ABSSSIs) at both a standard test of cure assessment time (8-15 days after discontinuation of study drug) and an early assessment time point (day 3 or 4 of study). In the integrated analysis of the trials for CABP (FOCUS 1 and 2), clinical cure rates for the ceftaroline group were numerically higher than those for the ceftriaxone group (for the clinically evaluable population 84.3% vs 77.7%; difference: 6.6%; 95% confidence interval, 1.6%-11.8%). Among patients with CABP caused by S. pneumoniae, clinical cure rates were markedly higher in the ceftaroline treatment group than in the ceftriaxone treatment group (59 of 69 [85.5%] vs 48 of 70 [68.6%], respectively). For the ABSSSI studies (CANVAS 1 and 2), microbiologically evaluable (ME) success rates were similar between the treatment groups. Notably, the clinical cure rates in ME patients with methicillin-resistant S. aureus ABSSSIs were 142 of 152 (93.4%) and 115 of 122 (94.3%), for ceftaroline and vancomycin plus aztreonam, respectively, and did not differ from those achieved in infections due to methicillin-susceptible S. aureus (93.0%-94.5%). Ceftaroline fosamil was well tolerated, with a safety profile similar to the comparator agents used in these phase 3 trials. PMID:22903949
In vitro antibacterial activity of different adenosine analogues.
Nucleoside analogues may represent good candidates for the discovery of new antibacterial agents, therefore, a library of adenosine analogues was assessed for their antibacterial activity, and the relationship between the structure and activity of these molecules was outlined. Antibacterial activity was evaluated against that of reference strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Escherichia coli and Pseudomonas aeruginosa. We tested 54 adenosine analogues, modified both at ribose and base moieties, including adenine and 1/3-deazaadenine derivatives substituted in the 2- and/or N(6)-positions and bearing N-9 sugar moieties, such as ribose, 2'-deoxyribose, 3'-deoxyribose, 2',3'-dideoxyribose or cycloalkyl groups like cyclopentane. The data obtained, MIC and minimal bactericidal concentrations demonstrated that the presence of bulky substituents such as cycloheptyl and cyclooctyl rings on the N(6)-amino, together with a chlorine atom in the 2-position, conferred antibacterial activity against the Gram-positive group with MIC values ranging from 16 to 128 mg l(-1). The intact sugar moiety seemed to be not essential for antimicrobial activity and nucleosides bearing deoxyribose or cyclopentyl groups associated with bulky substituents in N(6)-position showed good antimicrobial properties. Furthermore, N-1 proved to be non-crucial and the 2-chloro-N(6)-cyclooctyl-1-deaza-3'-deoxyadenosine and 2',3'-dideoxyadenosine compounds were among the more active in the series with an MIC of 32 mg l(-1) against Staph. aureus and Strep. pneumoniae. None of the analogues was active against the two gram-negative species tested. Hence, adenosine derivatives bearing bulky substituents in the N(6)-position may represent good lead compounds for the future discovery of a novel series of antibacterial agents. PMID:22160314
Characteristics and crystal structure of bacterial inosine-5'-monophosphate dehydrogenase.
IMP dehydrogenase (IMPDH) is an essential enzyme that catalyzes the first step unique to GTP synthesis. To provide a basis for the evaluation of IMPDH inhibitors as antimicrobial agents, we have expressed and characterized IMPDH from the pathogenic bacterium Streptococcus pyogenes. Our results show that the biochemical and kinetic characteristics of S. pyogenes IMPDH are similar to other bacterial IMPDH enzymes. However, the lack of sensitivity to mycophenolic acid and the K{sub m} for NAD (1180 {mu}M) exemplify some of the differences between the bacterial and mammalian IMPDH enzymes, making it an attractive target for antimicrobial agents. To evaluate the basis for these differences, we determined the crystal structure of the bacterial enzyme at 1.9 {angstrom} with substrate bound in the catalytic site. The structure was determined using selenomethionine-substituted protein and multiwavelength anomalous (MAD) analysis of data obtained with synchrotron radiation from the undulator beamline (19ID) of the Structural Biology Center at Argonne's Advanced Photon Source. S. pyogenes IMPDH is a tetramer with its four subunits related by a crystallographic 4-fold axis. The protein is composed of two domains: a TIM barrel domain that embodies the catalytic framework and a cystathione {beta}-synthase (CBS) dimer domain of so far unknown function. Using information provided by sequence alignments and the crystal structure, we prepared several site-specific mutants to examine the role of various active site regions in catalysis. These variants implicate the active site flap as an essential catalytic element and indicate there are significant differences in the catalytic environment of bacterial and mammalian IMPDH enzymes. Comparison of the structure of bacterial IMPDH with the known partial structures from eukaryotic organisms will provide an explanation of their distinct properties and contribute to the design of specific bacterial IMPDH inhibitors.
The activity of antibacterial agents against aerobic Gram-positive cocci (25 genus or species, 1029 strains) and anaerobic bacteria (21 genus or species, 187 strains) isolated from clinical specimens in 2008 at 16 clinical facilities in Japan were studied using either broth microdilution or agar dilution method. The ratio of methicillin-resistant strains among Staphylococcus aureus and Staphylococcus epidermidis was 59.6% and 81.2%, suggesting that resistant strains were isolated at high frequency. Vancomycin (VCM), linezolid (LZD) and quinupristin/dalfopristin (QPR/DPR) had good antibacterial activity against methicillin-resistant S. aureus and methicillin-resistant S. epidermidis, with MIC90s of < or = 2 microg/mL. The ratio of penicillin (PC) intermediate and resistant strains classified by mutations of PC-binding proteins among Streptococcus pneumoniae was 92.0% that was highest among our previous reports. Cefpirome, carbapenems, VCM, teicoplanin (TEIC), LZD and QPR/DPR had MIC90s of < or = 1 microg/mL against PC-intermediate and resistant S. pneumoniae strains. Against all strains of Enterococcus faecalis and Enterococcus faecium, the MICs of VCM and TEIC were under 2 microg/mL, and no resistant strain was detected, suggesting that these agents had excellent activities against these species. 15.9% of E. faecalis strains and 1.2% of E. faecium strains showed intermediate to LZD. 17.1% of E. faecium strains showed intermediate or resistant to QPR/DPR. Against all strains of Clostridium difficile, the MIC of VCM was under 1 microg/mL, suggesting that VCM had excellent activity. Carbapenems showed good activity against Clostridiales, Bacteroides spp., and Prevotella spp., but one strain of Bacteroides fragilis showed resistant to carbapenems. And so, the susceptibility of this species should be well-focused in the future at detecting continuously. PMID:22808693
Streptococcus mutans plays an important role in biofilm formation on the tooth surface and is the primary causative agent of dental caries. The binding of S. mutans to the salivary pellicle is of considerable etiologic significance and is important in biofilm development. Recently, we produced NOD/SCID.e2f1(-/-) mice that show hyposalivation, lower salivary antibody, and an extended life span compared to the parent strain: NOD.e2f1(-/-). In this study we used NOD/SCID.e2f1(-/-) 4 or 6 mice to determine the roles of several salivary components in S. mutans colonization in vivo. S. mutans colonization in NOD/SCID.e2f1(-/-) mice was significantly increased when mice were pre-treated with human saliva or commercial salivary components. Interestingly, pre-treatment with secretory IgA (sIgA) at physiological concentrations promoted significant colonization of S. mutans compared with sIgA at higher concentrations, or with human saliva or other components. Our data suggest the principal effects of specific sIgA on S. mutans occur during S. mutans colonization, where the appropriate concentration of specific sIgA may serve as an anti-microbial agent, agglutinin, or an adherence receptor to surface antigens. Further, specific sIgA supported biofilm formation when the mice were supplied 1% sucrose water and a non-sucrose diet. The data suggests that there are multiple effects exerted by sIgA in S. mutans colonization, with synergistic effects evident under the condition of sIgA and limited nutrients on colonization in NOD/SCID.e2f1(-/-) mice. This is a new animal model that can be used to assess prevention methods for dental biofilm-dependent diseases such as dental caries. PMID:22363797
National Oral Heal Surveillance System
Streptococcus mutans plays an important role in biofilm formation on the tooth surface and is the primary causative agent of dental caries. The binding of S. mutans to the salivary pellicle is of considerable etiologic significance and is important in biofilm development. Recently, we produced NOD/SCID.e2f1?/? mice that show hyposalivation, lower salivary antibody, and an extended life span compared to the parent strain: NOD.e2f1?/?. In this study we used NOD/SCID.e2f1?/? 4 or 6 mice to determine the roles of several salivary components in S. mutans colonization in vivo. S. mutans colonization in NOD/SCID.e2f1?/? mice was significantly increased when mice were pre-treated with human saliva or commercial salivary components. Interestingly, pre-treatment with secretory IgA (sIgA) at physiological concentrations promoted significant colonization of S. mutans compared with sIgA at higher concentrations, or with human saliva or other components. Our data suggest the principal effects of specific sIgA on S. mutans occur during S. mutans colonization, where the appropriate concentration of specific sIgA may serve as an anti-microbial agent, agglutinin, or an adherence receptor to surface antigens. Further, specific sIgA supported biofilm formation when the mice were supplied 1% sucrose water and a non-sucrose diet. The data suggests that there are multiple effects exerted by sIgA in S. mutans colonization, with synergistic effects evident under the condition of sIgA and limited nutrients on colonization in NOD/SCID.e2f1?/? mice. This is a new animal model that can be used to assess prevention methods for dental biofilm-dependent diseases such as dental caries. PMID:17498505
Abstract in english Background: Community-acquired pneumonia (CAP) is a common and serious illness in Chile. Aim: To evaluate the etiology, severity, prognostic factors and blood culture yield of CAP requiring hospitalization in Puerto Montt in Southern, Chile. Patients and methods: All non immunocompromised adults with CAP admitted at Puerto Montt Hospital during one year, were prospectively studied. Clinical and radiological assessment was done in all patients. Blood and sputum cultures we (more) re obtained and serology for atypical agents was determined. Results: We studied 200 patients, aged 63±19 years (109 males). The prognostic factors associated with mortality were an age over 65 years, an altered mental status, shock and acute renal failure. Etiology was demonstrated in 29% of patients. The most frequent pathogens were Streptococcus pneumoniae (40.7%), Haemophilus influenzae (23.7%) and Chlamydia pneumoniae (16.9%). Mixed infections were found in 17%. Fifteen atypical pathogens were identified in 12 patients. Of these only two received a specific treatment but no one died and their length hospital stay was similar than in the rest of the patients. Overall, blood cultures were positive in 12.5% of patients, but among alcoholics, 58% were positive. In only one percent of cases, positive cultures motivated therapeutic changes among clinicians. Eight percent of S pneumoniae strains were penicillin resistant. Conclusions: Atypical agents were a common cause of CAP in this group of patients, but their pathogenic role and treatment requirements are debatable. Focusing blood cultures on specific groups could improve their yield. The rate of Penicillin resistance for S pneumoniae was
Rotavirus Surveillance Worldwide, 2001-2008.
Background There are limited data on the etiology and characteristics of bloodstream infections in children presenting in hospital outpatient settings in South Asia. Previous studies in Nepal have highlighted the importance of murine typhus as a cause of febrile illness in adults and enteric fever as a leading bacterial cause of fever among children admitted to hospital. Methods We prospectively studied a total of 1084 febrile children aged between 2 months and 14 years presenting to a general hospital outpatient department in Kathmandu Valley, Nepal, over two study periods (summer and winter). Blood from all patients was tested by conventional culture and by real-time PCR for Rickettsia typhi. Results Putative etiological agents for fever were identified in 164 (15%) patients. Salmonella enterica serovar Typhi (S. Typhi) was identified in 107 (10%), S. enterica serovar Paratyphi A (S. Paratyphi) in 30 (3%), Streptococcus pneumoniae in 6 (0.6%), S. enterica serovar Typhimurium in 2 (0.2%), Haemophilus influenzae type b in 1 (0.1%), and Escherichia coli in 1 (0.1%) patient. S. Typhi was the most common organism isolated from blood during both summer and winter. Twenty-two (2%) patients were PCR positive for R. typhi. No significant demographic, clinical and laboratory features distinguished culture positive enteric fever and murine typhus. Conclusions Salmonella infections are the leading cause of bloodstream infection among pediatric outpatients with fever in Kathmandu Valley. Extension of immunization programs against invasive bacterial disease to include the agents of enteric fever and pneumococcus could improve the health of children in Nepal. PMID:19023263
The Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) surveillance program is a sentinel resistance monitoring system designed to track the activity of ceftaroline and comparator agents. In the United States, a total of 8,434 isolates were collected during the 2010 surveillance program from 65 medical centers distributed across the nine census regions (5 to 10 medical centers per region). All organisms were isolated from documented infections, including 3,055 (36.2%) bloodstream infections, 2,282 (27.1%) respiratory tract infections, 1,965 (23.3%) acute bacterial skin and skin structure infections, 665 (7.9%) urinary tract infections, and 467 (5.5%) miscellaneous other infection sites. Ceftaroline was the most potent ?-lactam agent tested against staphylococci. The MIC(90) values were 1 ?g/ml for methicillin-resistant Staphylococcus aureus (MRSA; 98.4% susceptible) and 0.5 ?g/ml for methicillin-resistant coagulase-negative staphylococci (CoNS). Ceftaroline was 16- to 32-fold more potent than ceftriaxone against methicillin-susceptible staphylococcal strains. All staphylococcus isolates (S. aureus and CoNS) were inhibited at ceftaroline MIC values of ? 2 ?g/ml. Ceftaroline also displayed potent activity against streptococci (MIC(90), 0.015 ?g/ml for beta-hemolytic streptococci; MIC(90), 0.25 ?g/ml for penicillin-resistant Streptococcus pneumoniae). Potent activity was also shown against Gram-negative pathogens (Haemophilus influenzae, Haemophilus parainfluenzae, and Moraxella catarrhalis). Furthermore, wild-type strains of Enterobacteriaceae (non-extended-spectrum ?-lactamase [ESBL]-producing strains and non-AmpC-hyperproducing strains) were often susceptible to ceftaroline. Continued monitoring through surveillance networks will allow for the assessment of the evolution of resistance as this new cephalosporin is used more broadly to provide clinicians with up-to-date information to assist in antibiotic stewardship and therapeutic decision making. PMID:22470115
The Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) surveillance program is a sentinel resistance monitoring system designed to track the activity of ceftaroline and comparator agents. In the United States, a total of 8,434 isolates were collected during the 2010 surveillance program from 65 medical centers distributed across the nine census regions (5 to 10 medical centers per region). All organisms were isolated from documented infections, including 3,055 (36.2%) bloodstream infections, 2,282 (27.1%) respiratory tract infections, 1,965 (23.3%) acute bacterial skin and skin structure infections, 665 (7.9%) urinary tract infections, and 467 (5.5%) miscellaneous other infection sites. Ceftaroline was the most potent ?-lactam agent tested against staphylococci. The MIC90 values were 1 ?g/ml for methicillin-resistant Staphylococcus aureus (MRSA; 98.4% susceptible) and 0.5 ?g/ml for methicillin-resistant coagulase-negative staphylococci (CoNS). Ceftaroline was 16- to 32-fold more potent than ceftriaxone against methicillin-susceptible staphylococcal strains. All staphylococcus isolates (S. aureus and CoNS) were inhibited at ceftaroline MIC values of ?2 ?g/ml. Ceftaroline also displayed potent activity against streptococci (MIC90, 0.015 ?g/ml for beta-hemolytic streptococci; MIC90, 0.25 ?g/ml for penicillin-resistant Streptococcus pneumoniae). Potent activity was also shown against Gram-negative pathogens (Haemophilus influenzae, Haemophilus parainfluenzae, and Moraxella catarrhalis). Furthermore, wild-type strains of Enterobacteriaceae (non-extended-spectrum ?-lactamase [ESBL]-producing strains and non-AmpC-hyperproducing strains) were often susceptible to ceftaroline. Continued monitoring through surveillance networks will allow for the assessment of the evolution of resistance as this new cephalosporin is used more broadly to provide clinicians with up-to-date information to assist in antibiotic stewardship and therapeutic decision making. PMID:20853007
Adenite equina: sua etiologia, diagnóstico e controle/ Strangles: etiology, diagnosis and control
Abstract in portuguese A adenite equina, também conhecida como garrotilho, é uma enfermidade bacteriana contagiosa, causada por Streptococcus equi, subsp. equi, bactéria ? hemolítica do grupo C de Lancefield, que afeta o trato respiratório anterior de equinos de todas as idades, com maior prevalência entre um e cinco anos de idade. Caracteriza-se por produzir secreção mucopurulenta das vias aéreas anteriores e linfadenite dos gânglios retrofaríngeos e submandibulares com formaç (more) ão de abscessos. Fatores de virulência de S. equi, subsp. equi, incluem cápsula de ácido hialurônico, hialuronidase, estreptolisina O, estreptoquinase, receptores para Fc de IgG, peptidoglicano e proteína M. Dentre esses fatores, a proteína M tem especial importância por ser de membrana com propriedades antifagocitárias e de aderência. A doença tem baixa letalidade e alta morbidade e seus prejuízos econômicos devem-se à perda de performance e custo do tratamento. O diagnóstico clínico e o tratamento não apresentam dificuldades, mas a profilaxia é prejudicada pela baixa eficiência das vacinas disponíveis, com índices de proteção de 50%. O garrotilho pode ocorrer em todas as épocas do ano, mas o frio e a umidade facilitam a sobrevivência do agente e sua disseminação, portanto animais que vivem nos estados mais frios e úmidos do país são mais vulneráveis à infecção. Novas vacinas utilizando antígenos purificados ou de subunidades estão sendo desenvolvidas com a finalidade de incrementar sua potência e evitar efeitos indesejáveis. A comprovação de diferenças de antigenicidade, entre estirpes, alerta sobre a importância da seleção apropriada das cepas vacinais. Abstract in english Strangles is a contagious disease of the respiratory tract of horses produced by Streptococcus equi subsp. equi, a Lancefield's group C ? haemolytic bacterium. It produces a mucopurulent secretion of the anterior airways, as well as lymphadenitis and abscesses. The bacteria synthesizes several pathogenicity factors such a hyaluronic acid capsule, hyaluronidase, streptolisin O, streptokinase, IgG Fc receptors, peptidoglican and protein M. Among these factors, protein (more) M deserves special importance due to its antifagocitic and adherence properties. The disease has high morbidity and low lethality, and produces economic losses due to low performance and treatment. Clinical diagnosis and treatment are done easily, but prophylaxis is hampered by the low potency of vaccines, that protect around 50 % of vaccinated animals. Strangles may occur during all the year, but cold and humid weather favors the survival of streptococci, making animals that live in regions with those characteristics more prone to infection. New vaccines using purified or subunit antigens have been developed aiming to increase their potency and to avoid undesirable side effects. The demonstration that bacteria strains show differences in their antigenicity, called attention on the selection of appropriate strains to use as antigens.
For the purpose of nationwide surveillance of antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, the Japanese Society of Chemotherapy (JSC) started a survey in 2006. From 2009, JSC continued the survey in collaboration with the Japanese Association for Infectious Diseases and the Japanese Society for Clinical Microbiology. The fourth-year survey was conducted during the period from January and April 2009 by the three societies. A total of 684 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 635 strains (130 Staphylococcus aureus, 127 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 123 Haemophilus influenzae, 70 Moraxella catarrhalis, 78 Klebsiella pneumoniae, and 103 Pseudomonas aeruginosa). A maximum of 45 antibacterial agents including 26 ?-lactams (four penicillins, three penicillins in combination with ?-lactamase inhibitors, four oral cephems, eight parenteral cephems, one monobactam, five carbapenems, and one penem), four aminoglycosides, four macrolides (including ketolide), one lincosamide, one tetracycline, two glycopeptides, six fluoroquinolones, and one oxazolidinone were used for the study. Analysis was conducted at the central reference laboratory according to the method recommended by the Clinical and Laboratory Standard Institute (CLSI). Incidence of methicillin-resistant S. aureus (MRSA) was as high as 58.5 %, and that of penicillin-intermediate and penicillin-resistant S. pneumoniae (PISP and PRSP) was 6.3 % and 0.0 %, respectively. Among H. influenzae, 21.1 % of them were found to be ?-lactamase-non-producing ampicillin (ABPC)-intermediately resistant (BLNAI), 18.7 % to be ?-lactamase-non-producing ABPC-resistant (BLNAR), and 5.7 % to be ?-lactamase-producing ABPC-resistant (BLPAR) strains. A high frequency (76.5 %) of ?-lactamase-producing strains has been suspected in Moraxella catarrhalis isolates. Four (3.2 %) extended-spectrum ?-lactamase-producing K. pneumoniae were found among 126 strains. Four isolates (2.5 %) of P. aeruginosa were found to be metallo-?-lactamase-producing strains, including three (1.9 %) suspected multi-drug resistant strains showing resistance against imipenem, amikacin, and ciprofloxacin. Continuous national surveillance of the antimicrobial susceptibility of respiratory pathogens is crucial to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis. PMID:22766652
Abstract in english Gram-positive cocci are important causes of both nosocomial and community-acquired infections, and antimicrobial resistance among these pathogens has become an important problem worldwide. Since resistance among these organisms can vary substantially by geographic location, we conducted a multicenter surveillance study with isolates from five Latin American countries (15 medical centers). Quinupristin/dalfopristin (formerly RP-59500) is a novel streptogramin combination w (more) ith focused activity against Gram-positive cocci, many exhibiting emerging resistance. The in vitro activity of quinupristin/dalfopristin and 12 other antimicrobial agents were evaluated against 1,948 strains including Staphylococcus aureus (747 strains), coagulase-negative staphylococci (CoNS; 446 strains), enterococci (429 strains), and various Streptococcus spp. (326 strains). Oxacillin resistance was observed in 41% of S. aureus (MIC, or = 13 mm) and 40% of CoNS (MIC, or = 18 mm). Vancomycin, teicoplanin, and quinupristin/dalfopristin (MIC90, 0.25 - 1 mug/ml) remained effective against all strains, but cross-resistance was high among other tested drugs. The quinupristin/dalfopristin MIC50 for Streptococcus pneumoniae and other streptococci was only 0.5 mug/ml (13% to 28% were penicillin-resistant; 12% to 22% were macrolide-resistant). Enterococci demonstrated variable inhibition by quinupristin/dalfopristin depending upon identification and the susceptibility testing method used. The demonstrated quinupristin/dalfopristin activity against Enterococcus faecium was confirmed, but potential species identification errors with various commercial systems continue to confuse susceptibility statistics, even though some strains of E. faecium confirmed by PCR-based or other molecular identification techniques did have quinupristin/dalfopristin MICs of > or = 4 mug/mL. Most important, glycopeptide-resistant enterococci are rapidly emerging in Latin America, and quinupristin/dalfopristin appears active against many of these isolates as well as having potency against nearly all staphylococci and streptococci tested at or = 16 mm. Comparisons to GSMART results from other continents show nearly identical quinupristin/dalfopristin activity for each Gram-positive species tested. These results define the role of quinupristin/dalfopristin in Latin American medical centers and provide a benchmark for future in vitro comparisons.
Abstract in portuguese Objetivos: Estudar a microbiota aeróbica conjuntival em pacientes com quadro clínico de conjuntivite viral aguda. Método: Trinta pacientes entre 18 e 40 anos portadores de conjuntivite adenoviral e 30 pacientes sem a doença foram submetidos à colheita de material da conjuntiva para cultura. Os portadores de conjuntivite adenoviral foram submetidos ao exame até 3 dias após o início dos sintomas. As culturas foram realizadas utilizando-se os meios de ágar-sangue e (more) ágar-chocolate. Pacientes em uso de medicação tópica ou sistêmica, usuários de lentes de contato e aqueles com doença ocular prévia ou doença sistêmica foram excluídos. Resultados: Houve positividade significantemente maior das culturas de conjuntiva nos pacientes com conjuntivite adenoviral (33,3%, sendo Haemophylus influenzae em 50% e Streptococcus pneumoniae em 50%) quando comparados ao grupo controle (6,6% - Staphylococcus coagulase negativo). O grupo de pacientes com conjuntivite e que apresentaram culturas positivas, não diferiu em nenhum dos critérios clínicos analisados do grupo com culturas negativas. Conclusão: Pacientes com conjuntivite adenoviral apresentaram maior freqüência de exames de cultura de amostra de conjuntiva positivas quando comparados aos controles normais. Os pacientes com conjuntivite adenoviral com cultura positiva apresentaram evolução clínica semelhante aos pacientes com cultura negativa. Os agentes isolados na microbiota conjuntival no grupo com conjuntivite foram diferentes do observado no grupo normal. Porém o resultado das culturas não apresentou correlação com a evolução clínica. Abstract in english Purpose: To study the aerobic bacterial conjunctival flora in patients with clinical diagnosis of acute viral conjunctivitis. Method: Thirty patients between 18 and 30 years with acute adenoviral conjunctivitis and 30 normal subjects underwent conjunctival culture examination. Material from the conjunc-tiva of patients with conjunctivitis was collected within the first 3 days of onset of the symptoms. Blood-agar and chocolate-agar plates were used for culture. Patients un (more) der any topical or systemic medication, contact lens wearers, patients with ocular or systemic disease were excluded. Results: Significant positivity in culture results of patients with adenoviral conjunctivitis was observed (33.3%, among which 50% were Haemophylus influenzae and 50% were Streptococcus pneumoniae), when compared to conjunctival culture of normal subjects (6.6% of coagulase-negative staphylococci). There was no clinical difference related to the isolation of bacteria in the conjunctival sample of all patients. Conclusion: Patients with clinically diagnosed viral conjunctivitis have a higher rate of positive cultures when compared to controls. Nevertheless, this finding does not correlate with clinical differences. Microorganisms isolated in the conjunctiva of patients with adenoviral conjunctivitis were different from those isolated in the conjunctiva of normal subjects.
Abstract in spanish Introducción. Haemophilus influenzae, Streptococcus pneumoniae y Neisseria meningitidis son los principales patógenos humanos causantes de meningitis. Objetivo. Se evaluaron los iniciadores omp2, lytA y crgA en el desarrollo de una reacción en cadena de la polimerasa múltiple, para la identificación simultánea de los tres principales microorganismos responsables de la meningitis bacteriana. Materiales y métodos. Se evaluaron en un formato de PCR múltiple los inici (more) adores para la proteína de membrana externa (omp2, 1.000 pb) de H. influenzae, la autolisina A (LytA, 395 pb) de S. pneumoniae y el gen regulador de contacto A (cgrA, 230 pb) de N. meningitidis y se determinó la sensibilidad y la especificidad de la técnica. Resultados. Se obtuvieron resultados reproducibles con una concentración de 50 nM de cada uno de los tres iniciadores y una temperatura de anillamiento de 57°C obteniendo una sensibilidad de 12,5 fg para H. influenzae y S. pnemoniae y de 3,12 fg para N. meningitidis. No se presentaron reacciones cruzadas con otros microorganismos causantes de meningitis o relacionados con los géneros. Conclusión. Los resultados de sensibilidad y especificidad sugieren que los iniciadores evaluados pueden ser utilizados para el desarrollo de una PCR en formato múltiple que permita la identificación de los tres principales patógenos causantes de meningitis. Abstract in english Introduction: Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis are the main human pathogens that cause meningitis. Objective: Primers omp2, lytA and crgA were evaluated with H. influenzae, S. pnumoniae and N. meningitidis DNA in a multiplex PCR, determining the sensitivity and the specificity of the technique. Materials and methods: Primers for H. influenzae outer membrane protein (omp2, 1000 pb), S. pneumoniae autolysin (lytA, 395 pb) and N. me (more) ningitidis, contact regulated gene (crgA, 230 pb) were evaluated in a multiplex PCR, determining the sensitivity and the specificity of the technique. Results: Reproducible results were obtained with 50 nM of each of the three primers and annealing temperature of 57°C in the multiplex PCR, obtaining a sensitivity of 12.5 fg for H. influenzae and S. pneumoniae and 3.12 fg for N. meningitidis. No cross reactions with other microorganisms agents of meningitis or related with the genera, appeared. Conclusions: The results for sensitivity and specificity suggest that the evaluated primers can be used for the development of a PCR in a multiplex format to the identification of the three main pathogens that cause meningitis.
Abstract in spanish La neumonía es la principal causa única de mortalidad entre los menores de cinco años. Se estima que la incidencia en ese grupo de edad es de 0,29 episodios por niño y año en los países en desarrollo y de 0,05 episodios por niño y año en los países desarrollados. Ello se traduce en unos 156 millones de episodios nuevos cada año en todo el mundo, de los cuales 151 millones se registran en el mundo en desarrollo. La mayoría de los casos se dan en la India (43 mil (more) lones), China (21 millones), el Pakistán (10 millones), y también presentan cifras altas Bangladesh, Indonesia y Nigeria (6 millones cada uno). De todos los casos comunitarios, un 7%-13% son lo bastante graves para poner en peligro la vida y requerir hospitalización. Numerosos datos demuestran que los principales factores de riesgo de la incidencia de neumonía son la falta de lactancia materna exclusiva, la desnutrición, la contaminación del aire en locales cerrados, el bajo peso al nacer, el hacinamiento y la falta de inmunización contra el sarampión. La neumonía provoca aproximadamente un 19% de todas las defunciones entre los niños menores de cinco años, y más del 70% de esas muertes se producen en el África subsahariana y en Asia sudoriental. Aunque la evidencia disponible es aún limitada, estudios recientes señalan a Streptococcus pneumoniae, Haemophilus influenzae y el virus sincitial respiratorio como los principales agentes patógenos asociados a la neumonía en la niñez. Abstract in english Childhood pneumonia is the leading single cause of mortality in children aged less than 5 years. The incidence in this age group is estimated to be 0.29 episodes per child-year in developing and 0.05 episodes per child-year in developed countries. This translates into about 156 million new episodes each year worldwide, of which 151 million episodes are in the developing world. Most cases occur in India (43 million), China (21 million) and Pakistan (10 million), with addit (more) ional high numbers in Bangladesh, Indonesia and Nigeria (6 million each). Of all community cases, 7-13% are severe enough to be life-threatening and require hospitalization. Substantial evidence revealed that the leading risk factors contributing to pneumonia incidence are lack of exclusive breastfeeding, undernutrition, indoor air pollution, low birth weight, crowding and lack of measles immunization. Pneumonia is responsible for about 19% of all deaths in children aged less than 5 years, of which more than 70% take place in sub-Saharan Africa and south-east Asia. Although based on limited available evidence, recent studies have identified Streptococcus pneumoniae, Haemophilus influenzae and respiratory syncytial virus as the main pathogens associated with childhood pneumonia.
Oral microbial biofilm stimulation of epithelial cell responses
Oral bacterial biofilms trigger chronic inflammatory responses in the host that can result in the tissue destructive events of periodontitis. However, the characteristics of the capacity of specific host cell types to respond to these biofilms remain ill-defined. This report describes the use of a novel model of bacterial biofilms to stimulate oral epithelial cells and profile select cytokines and chemokines that contribute to the local inflammatory environment in the periodontium. Monoinfection biofilms were developed with Streptococcus sanguinis, Streptococcus oralis, Streptococcus gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis on rigid gas-permeable contact lenses. Biofilms, as well as planktonic cultures of these same bacterial species, were inc...
Major mastitis pathogens such as Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, Streptococcus dysgalactiae, and the coliforms are usually considered more virulent and damaging to the udder than minor mastitis pathogens such as Corynebacterium bovis and coagulase-negative staphylococci (CNS). The current literature contains several studies detailing analyses with conflicting results as to whether intramammary infection (IMI) with the minor pathogens decreases, increases, or has no effect on the risk of a quarter acquiring a new intramammary infection (NIMI) with a major pathogen. To investigate the available scientific evidence regarding the effect of IMI with minor pathogens on the acquisition of NIMI with major pathogens, a systematic review and meta-analysis were ...
Streptococcus sanguis Meningitis: Report of a Case and Review of the Literature
Viridans streptococcus, an indigenous bacterial species of the mouth and gastrointestinal tract, is thought to be a rare cause of bacterial meningitis. The type of streptococcus involved is important because each type causes a different kind of meningitis and is associated with a different outcome. A 39-year-old previously healthy man was admitted due to the onset of acute purulent meningitis. A cerebrospinal fluid culture grew Streptococcus sanguis (S. sanguis). Although the patient was asymptomatic for dental caries, odontogenic maxillary sinusitis was found to be the cause of the meningitis. Treatment with intravenous antibiotics was successful. Following a review of the pertinent literature, we discuss the characteristics of S. sanguis meningitis.
Future challenges in the elimination of bacterial meningitis
Despite the widespread implementation of several effective vaccines over the past few decades, bacterial meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis and Group B Streptococcus (GBS) still results in unacceptably high levels of human mortality and morbidity. A residual disease burden due to bacterial meningitis is also apparent due to a number of persistent or emerging pathogens, including Mycobacterium tuberculosis, Escherichia coli, Staphylococcus aureus, Salmonella spp. and Streptococcus suis. Here, we review the current status of bacterial meningitis caused by these pathogens, highlighting how past and present vaccination programs have attempted to counter these pathogens. We discuss how improved pathogen surveillance, implementation of c...
Abstract Aims:- To investigate the effect of seven wine phenolic compounds and six oenological phenolic extracts on the growth of pathogenic bacteria associated with respiratory diseases (Pseudomonas aeruginosa, Staphylococcus aureus, Moraxella catarrhalis, Enterococcus faecalis, Streptococcus sp Group F, Streptococcus agalactiae and Streptococcus pneumoniae). Methods and Results:- Antimicrobial activity was determined using a microdilution method and quantified as IC50. Mor.catarrhalis was the most susceptible specie to phenolic compounds and extracts. Gallic acid and ethyl gallate were the compounds that showed the greatest antimicrobial activity. Regarding phenolic extracts, GSE (grape seed extract) and GSE-O (oligomeric-rich fraction from GSE) were the ones that displayed the strongest...
The aim of this study was to evaluate the in vitro activity of cefditoren and comparators against Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis causing community-acquired respiratory tract infections (CARTIs). A total of 391 Streptococcus pneumoniae, 266 H. influenzae, and 76 M. catarrhalis were isolated from 10 centers located at 6 cities in China from January 2009 to May 2010. The microdilution method was used to determine minimum inhibitory concentrations (MICs). The pneumococci comprised 189 (48.3%) penicillin susceptible, 129 (33.0%) penicillin intermediate, and 73 (18.7%) penicillin resistant. Moxifloxacin and levofloxacin showed the highest activity (99.2% and 97.7%, respectively) against Streptococcus pneumoniae, followed by parenteral penicillin G (95...
Abstract in portuguese A mastite é a inflamação da glândula mamária que acomete raças de aptidão leiteira como também aquelas voltadas para produção de carne. Esta enfermidade ocasiona sérias alterações na produção de leite e na sua qualidade, redução no ganho de peso e mortalidade de cordeiros. O presente estudo teve por objetivo conhecer os principais agentes causadores de mastite em ovinos e caprinos, bem como a sua susceptibilidade aos agentes antimicrobianos, além de aval (more) iar o grau de concordância entre testes diagnósticos. Foram visitadas 25 propriedades durante a realização do experimento, sendo criatórios de caprinos, ovinos e rebanhos mistos, nos estados de Pernambuco e Bahia. Coletou-se leite de 439 caprinos e 76 ovinos. Foi realizada lactocultura, o California Mastitis Test (CMT) e o teste de sensibilidade aos antimicrobianos. Além disso, determinou-se o grau de concordância entre os testes diagnósticos empregados. Foi constatada uma maior freqüência de Staphylococcus spp. nos casos de mastite em caprinos e ovinos, sendo observado ainda, isolados de Streptococcus spp., Corynebacterium spp. e bacilos gram negativos (BGN). Os isolados apresentaram alta sensibilidade aos antimicrobianos testados, sendo o menor percentual de sensibilidade observado para o ácido nalidíxico. Em relação ao diagnóstico da mastite caprina, a análise comparativa entre o exame microbiológico e o CMT demonstrou um grau de concordância igual a K=0,17, enquanto que para a espécie ovina, este valor foi de K=0,22. A utilização do CMT para o diagnóstico da mastite subclínica em cabras e ovelhas deverá ser associado à técnica da lactocultura. Abstract in english Mastitis is an inflammation of mammary gland, that are important in milking breed as well in meat ones. It is associated with serious reduction in milk production and quality, lambs weight gain reduction and mortality The goal of this work was determine the major etiologic agents of goat and sheep mastitis, as well as antimicrobial drug-resistance patterns and the agreement between two different diagnostic tools. We visit 25 goat, sheep, and goat and sheep farms in Pernam (more) buco and Bahia State, and a total of 439 goats and 76 sheep milk samples were collected. To diagnose of small ruminant mastitis were compared two tests: Milk culture and California Mastitis Test (CMT). The bacterial drug-resistance pattern was determined by Kirby Bauer test. Staphylococcus spp. was the most frequent bacteria isolated from goat and sheep mastitis cases. Streptococcus spp., Corynebacterium spp. and gram-negative bacilli were isolated. It was possible to observe the high sensitivity to antimicrobial drugs in all tested bacteria, being the lower sensitivity percentage determined to nalidixic acid. Considering caprine mastitis diagnostic the comparative analysis between microbiologic culture and shown a concordance degree of K=0,17, although to ovine species these value was K=0,22. The use of CMT to subclinical mastitis diagnostic in goat and ewes must be associated to milk bacterial culture.
Abstract in portuguese Cepas de Streptococcus salivarius, isoladas de crianças com e sem dor de garganta, foram testadas quanto à produção de bacteriocina contra Streptococcus pyogenes. Os resultados mostraram que as crianças que não tinham dor de garganta possuiam, na boca, cepas de bactérias produtoras de substâncias inibidoras semelhantes à bacteriocina contra S. pyogenes. Abstract in english Streptococcus salivarius strains, isolated from children with and without sore throat, were tested for bacteriocin production against Streptococcus pyogenes. S. salivarius strains producing bacteriocin-like inhibitory substances (BLIS) against S. pyogenes were more frequently found in children without sore throat. These results suggest that these children may be protected against sore throat by the presence of BLIS-positive S. salivarius strains.
Systemic infection with Streptococcus pneumoniae produced atrophy, decreased twitch and tetanic tension, and altered intracellular electrolyte composition in rat skeletal muscle. Cathepsin B activity was selectively elevated early in the course of illness. Luepeptin, a cathepsin B inhibitor, and ind...
In Vivo Activity of HSR-903, a New Fluoroquinolone, against Respiratory Pathogens
The in vivo activity of HSR-903, a new fluoroquinolone, against major bacteria which cause respiratory tract infections was evaluated. HSR-903 was active against experimental respiratory tract infections in mice challenged with penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae...
In-vitro Comparison of Erythromycin, Lincomycin, and Clindamycin
The in-vitro antibacterial activities of erythromycin, lincomycin, and clindamycin, a new derivative of lincomycin, were compared. Clindamycin was always more active than lincomycin, and was either as active as erythromycin or more so against betahaemolytic streptococci, Streptococcus viridans, Str....
Opsonic requirements for phagocytosis of Streptococcus pneumoniae types VI, XVIII, XXIII, and XXV.
An assay system employing radiolabeled, heat-killed Streptococcus pneumoniae and human polymorphonuclear leukocytes was utilized to study serum pneumococcal opsonic requirements. Comparing the kinetics of phagocytosis in normal serum, heat-inactivated serum, immunoglobulin G (IgG)-deficient serum, C...
We measured the luminol- and lucigenin-enhanced chemiluminescent response of human polymorphonuclear leukocytes (PMN) stimulated by various strains of Streptococcus pneumoniae and Haemophilus influenzae. In the absence of opsonin, phagocytosis of either bacterial species elicited good PMN response w...
Nagashima S, Yoshida A, Ansai T, Watari H, Notomi T, Maki K, Takehara T. Rapid detection of the cariogenic pathogens Streptococcus mutans and Streptococcus sobrinus using loop-mediated isothermal amplification.Oral Microbiol Immunol 2007: 22: 361-368Copyright 2007 The Authors. Journal compilation Copyright 2007 Blackwell Munksgaard. Introduction: Streptococcus mutans and Streptococcus sobrinus are associated with the development of dental caries in humans. In this study, we developed a rapid, sensitive method for detecting these major cariogenic pathogens using loop-mediated isothermal amplification (LAMP). The assay procedure is quite simple: the amplification is carried out in a single tube under isothermal conditions at 63degreeC, and the result can be obtained in less than 1 h. Methods...
Streptococcus pneumoniae is a major pathogen causing community-acquired pneumonia and acute bronchitis. Macrolides, fluoroquinolones (FQs), and, recently, telithromycin (TEL) constitute primary therapeutic options, and rare cases of resistance have been reported. In this report, we describe the emer...
Lymphocyte responses to the mitogens phytohemagglutinin and concanavalin A and to Streptococcus pyogenes, Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa were evaluated in patients with cystic fibrosis and in normal individuals. Lymphocyte proliferation in vitro was stimula...
Enzymatic removal and disinfection of bacterial biofilms.
Model biofilms of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas fluorescens, and Pseudomonas aeruginosa were made on steel and polypropylene substrata. Plaque-resembling biofilms of Streptococcus mutans, Actinomyces viscosus, and Fusobacterium nucleatum were made on saliva-coated hy...
The serum bactericidal activity of ciprofloxacin against strains of Streptococcus pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa for which MICs are similar (0.4 microgram/ml) was assessed with serum ultrafiltrates from five healthy volunteers receiving ciprofloxacin at 400 mg intraven...
Ribosomal resistance of clinical enterococcal to streptomycin isolates.
The mechanism of high-level resistance to streptomycin was studied in 12 clinical isolates of Streptococcus faecalis. Six strains produced streptomycin-modifying enzymes. Each of three enzyme-negative strains tested demonstrated ribosomal resistance to streptomycin. Lack of ribosomal susceptibility ...
This report describes the capacities of ampicillin, vancomycin, streptomycin, gentamicin, and combinations thereof to prevent endocarditis in rabbits challenged with either streptomycin-resistant (three strains) or streptomycin-susceptible (one strain) Streptococcus faecalis. Vancomycin (15 mg/kg) a...
Lipoteichoic acid (LTA) is an amphiphilic polycondensate located in the cell envelope of Gram-positive bacteria. In this study, LTAs were isolated from the three bovine mastitis species Streptococcus uberis 233, Streptococcus dysgalactiae 2023, and Streptococcus agalactiae 0250. Structural investigations of these LTAs were performed applying 1D and 2D nuclear magnetic resonance experiments as well as chemical analyses and mass spectrometry. Compositional analysis revealed the presence of glycerol (Gro), Glc, alanine (Ala), and 16:0, 16:1, 18:0, 18:1. The LTAs of the three Streptococcus strains possessed the same structure, that is, a lipid anchor comprised of ?-Glcp-(1?2)-?-Glcp-(1?3)-1,2-diacyl-sn-Gro and the hydrophilic backbone consisting of poly(sn-Gro-1-phosphate) randomly substituted at O-2 of Gro by d-Ala. PMID:23036931
The molecular genetics of macrolide resistance were analyzed in 49 clinical pneumococci (including an “atypical” bile-insoluble strain currently assigned to the new species Streptococcus pseudopneumoniae) with efflux-mediated erythromycin resistance (M phenotype). All test strains had the mef gene, ...
Meningitis is the most serious of invasive infections caused by the Gram-positive bacterium Streptococcus pneumoniae. Vaccines protect only against a limited number of serotypes, and evolving bacterial resistance to antimicrobials impedes treatment. Further insight into the molecular pathogenesis of...
With the emergence of ?-lactam antibiotic resistance among strains of Streptococcus pneumoniae, vancomycin has assumed an important role in the treatment of bacterial meningitis. Using the rabbit meningitis model, we evaluated the pharmacokinetics and pharmacodynamics of vancomycin in this setting. ...
Bacterial meningitis in HIV-infected patients: Case reports and review of the literature
Meningitis is not an uncommon complication of the acquired immune deficiency syndrome. Purulent meningitis is not a well recognized infection in human immunodeficiency virus (HIV) positive patients. Three cases of bacterial meningitis caused by Streptococcus pneumoniae, Neisseria meningitidis and Li...
Polymerase Chain Reaction Assay and Bacterial Meningitis Surveillance in Remote Areas, Niger
To compensate for the lack of laboratories in remote areas, the national reference laboratory for meningitis in Niger used polymerase chain reaction (PCR) to enhance the surveillance of meningitis caused by Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. PCR effectively...
Streptococcus iniae is a significant bacterial pathogen that causes hemorrhagic septicemia and meningoencephalitis in tilapia, hybrid striped bass, rainbow trout, olive flounder, yellowtail, barramundi and other species of cultured and wild fish worldwide. In tilapia production, vaccination of fry ...
In vitro susceptibilities of oral bacterial isolates to spiramycin.
Four hundred strains of oral bacteria were tested for their susceptibility to spiramycin. Actinobacillus actinomycetemcomitans and most species of Lactobacillus were resistant to the antibiotic. All strains of cariogenic Streptococcus mutans and most strains of bacterial species implicated in adult ...
Streptococcus mutans strain B13 (serotype D) almost exclusively produced free glucosyltransferase (GTase) in the culture supernatant when grown in sucrose-free TTY broth medium, which was composed of Trypticase (Baltimore Biological Laboratory [BBL] Cockeysville, Md.), tryptose (Difco Laboratories, ...
Using total internal reflection fluorescence microscopy, we directly observed the interaction between dextran and glucosyltransferase I (GTF) of Streptococcus sobrinus. Tetramethylrhodamine (TMR)-labeled GTF molecules were individually imaged as they were associating with and then dissociating from ...
A glucosyltransferase which synthesized insoluble glucan in polyacrylamide gel was isolated from the culture supernatant of Streptococcus mutans Ingbritt (serotype c) by ultrafiltration, ethanol fractionation, isoelectric focusing, and preparative gel electrophoresis. The enzyme preparation was elec...
Glucans synthesized by glucosyltransferase enzymes of oral streptococci facilitate bacterial accumulation on surfaces. The Streptococcus gordonii glucosyltransferase gene, gtfG, is positively regulated by rgg, which encodes a putative cytoplasmic protein. The gtfG promoter and ribosomal binding sequ...
Recent evidence supports the contribution of a multidrug efflux mechanism to fluoroquinolone resistance in Streptococcus pneumoniae. In this paper I show that reserpine, an inhibitor of multidrug transporters in gram-positive bacteria, dramatically suppresses the in vitro emergence of ciprofloxacin-...
Streptococcus iniae and S. agalactiae are usually not considered pathogens of channel catfish, Ictalurus punctatus, though concurrent infections may decrease catfish survival when infected with streptococcal organisms. Non-parasitized or naturally-parasitized channel catfish fry were challenged wit...
Streptococcus iniae and S. agalactiae are generally not considered pathogens of channel catfish, Ictalurus punctatus, but concurrent parasitism may increase catfish susceptibility to these streptococcal organisms. Young channel catfish with mild-to-moderate Trichodina spp. parasitism on the gills a...
The pathogens Streptococcus pyogenes and Moraxella catarrhalis colonize overlapping regions of the human nasopharynx. We have found that M. catarrhalis can dramatically increase S. pyogenes adherence to human epithelial cells and that species-specific coaggregation of these bacteria correlates with ...
Resistance of Group B Streptococcus to Selected Antibiotics, Including Erythromycin and Clindamycin
Resistance of group B streptococcus (GBS) to antibiotics, particularly erythromycin and clindamycin, was studied. Erythromycin resistance was present in 22% of GBS isolates, and these isolates were constitutively resistant, inducibly resistant, or sensitive to clindamycin. Erythromycin and clindamyc...
Sulfonamide resistance in recent isolates of Streptococcus pyogenes was found to be associated with alterations of the chromosomally encoded dihydropteroate synthase (DHPS). There were 111 different nucleotides (13.8%) in the genes found in susceptible and resistant isolates, respectively, resulting...
Twelve isolates of Streptococcus pneumoniae with decreased susceptibility by oxacillin screen were susceptible by the FOX panel (Micro Media Systems, Cleveland, Ohio), a commercial microdilution system designed for fastidious organisms. These organisms were found to be moderately susceptible or resi...
Localization of Streptococcus mutans GS-5 glucosyltransferases and intracellular invertase.
Antibodies directed against Streptococcus mutans GS-5 intracellular invertase and glucosyltransferase fractions capable of synthesizing primarily water-soluble or insoluble glucans were used to ultrastructurally localize the enzymes by means of the unlabeled antibody peroxidase-antiperoxidase method...
Active site restructuring regulates ligand recognition in class A penicillin-binding proteins
Bacterial cell division is a complex, multimolecular process that requires biosynthesis of new peptidoglycan by penicillin-binding proteins (PBPs) during cell wall elongation and septum formation steps. Streptococcus pneumoniae has three bifunctional (class A) PBPs that catalyze both polymerization ...
Antimicrobial Potency of the Leaf – Stalk Extract of Curcuma longa (LINN)
The methanolic extract of the leaf-stalk of curcuma longa LINN, was tested for its minimum Inhibitor concentration (MIC) against Gram positive-staphylococcus aureus, Bacillus pumilus, Bacillus subtilis, klebsiella pnemoniae, bacillus cereus, streptococcus pneumoniae, Lactobacillus arabinosus and gra...
Lysis of Streptococcus mutans by hen egg white lysozyme and inorganic sodium salts.
Streptococcus mutans BHT was grown in a synthetic medium containing radioactive thymidine to monitor deoxyribonucleic acid release. Kinetic experiments demonstrated that although lysozyme alone could not liberate deoxyribonucleic acid, cellular deoxyribonucleic acid was liberated from lysozyme-treat...
BIOENERGETIC CONFIRMATION OF VIABLE PATHOGENS IN FOODS BY ATP-BIOLUMINESCENCE
The cellular ATP content of fourteen freshly harvested bacteria including Bacillus, Campylobacter, Citrobacter, Escherichia, Lactobacillus, Listeria, Pediococcus, Pseudomonas, Salmonella, Streptococcus and Yersinia, was determined using a luciferin-luciferase bioluminescence approach. Incubation of...
Middle Ear Fluid Cytokine and Inflammatory Cell Kinetics in the Chinchilla Otitis Media Model
Streptococcus pneumoniae is the most frequent microbe causing middle ear infection. The pathophysiology of pneumococcal otitis media has been characterized by measurement of local inflammatory mediators such as inflammatory cells, lysozyme, oxidative metabolic products, and inflammatory cytokines. T...
Streptococcus iniae, a Gram-positive bacterium, and Vibrio vulnificus, a halophilic Gram-negative bacterium, have been associated with severe disease impacting tilapia aquaculture. Recent reports suggest both bacteria have been associated independently and concomitantly with disease on commercial f...
The autolytic LytA amidase from 12 bile (deoxycholate)-insoluble streptococcal isolates (formerly classified as atypical Streptococcus pneumoniae) showing different antibiotic resistance patterns was studied. These atypical strains, which autolyze at the end of the stationary phase of growth, contai...
In vitro evaluation of the antimicrobial activity of five root canal sealers.
The aim of the present study was to analyze the antimicrobial properties of five endodontic sealers: Endo Fill, Endomethasone, Endomethasone N, Sealer 26 and AH-Plus, against the following microorganisms: Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus sanguis and Actin...
Bacterial aggregating activity in human saliva: comparisons of bacterial species and strains.
Using a quantitative assay to measure saliva-mediated bacterial aggregating activity, we have surveyed 20 streptococcal strains with saliva samples obtained from a large population study. Individual saliva samples demonstrated characteristic levels of aggregating activity for Streptococcus sanguis M...
Fundus lesions after carotid injection of Streptococcus mutans in monkeys.
Carotid injection of Streptococcus mutans in pigtail monkeys caused fundus lesions clinically resembling those seen in humans with bacteremia. On histopathological examination microabscesses occurred in the retina, choroid, and optic nerve. Bacteria were observed in the histopathological sections of...
A luminol-enhanced chemiluminescence assay was used to investigate opsonic requirements for phagocytosis of STreptococcus pneumoniae serotypes VII, XIV, and XIX. After opsonization with whole immune sera (with antibody and total complement pathway), heat-inactivated immune sera (with antibody alone)...
Streptococcus suis infection in Taiwan, 2000-2011
From 2000 to 2011, 8 patients with Streptococcus suis infections were identified in Taiwan. Six isolates were initially misidentified as Streptococcus acidominimus using commercial identification systems and later confirmed to be S. suis using 16S rRNA gene sequencing analysis. Among the 7 isolates available for further analysis, all belonged to biotype II. Three serotype I isolates possessed the same genotypes, indicating the possible clonal spread of S. suis. All of these patients survived. S. suis infection is underestimated in Taiwan.
Of 368 acute otitis media (AOM) cases among 7-valent pneumococcal conjugate-vaccinated children, 43.5% were colonized by multiple otopathogens in the nasopharynx but only 7.1% experienced polymicrobial AOM. When co-colonization occurred, Haemophilus influenzae predominated over all Streptococcus pneumoniae strains except 19A strains to cause AOM. Haemophilus influenzae and Streptococcus pneumoniae both predominated over Moraxella catarrhalis to cause AOM. PMID:22301480
Endocarditis infecciosa activa: 152 casos/ Active infective endocarditis: 152 cases
Abstract in spanish La endocarditis infecciosa es una enfermedad de baja incidencia que en las últimas décadas mostró modificaciones respecto de su presentación, posibilidad diagnóstica y tratamiento. A pesar de estos avances, la mortalidad hospitalaria sigue siendo muy elevada. Nuestro objetivo fue analizar las características de los pacientes con endocarditis infecciosa activa y su relación con la mortalidad hospitalaria a lo largo de 16 años. Se realizó un registro prospectivo en (more) tre 1994 y 2010 de pacientes ingresados con endocarditis. Se analizaron características clínicas, evolución y tratamiento y se registraron los eventos intrahospitalarios. Ingresaron 152 pacientes, 64.5% varones, edad 45 ± 16 años, las causas más frecuentes de cardiopatía de base fueron: congénita 32 (21%) y reumática 20 (13.2%). Los motivos de internación fueron síndrome febril 116 (76.3%) e insuficiencia cardíaca 61 (40.1%). Se identificó el agente infeccioso en 106 (69.7%) de los casos, el más frecuente fue Streptococcus viridans. El ecocardiograma mostró vegetaciones en 123 (80.9%) de los pacientes y 88 (57.8%) presentaron complicaciones durante su internación, siendo la más frecuente la insuficiencia cardíaca. Se indicó tratamiento quirúrgico en 96 (63.1%) de los casos, fundamentalmente por insuficiencia cardíaca en 66. La mortalidad hospitalaria global fue 46 (30.2%). El desarrollo de complicaciones en la internación, la indicación de cirugía y la presencia de insuficiencia cardíaca refractaria al tratamiento fueron predictores independientes de mortalidad hospitalaria, mientras que la presencia de vegetaciones resultó un predictor independiente de mejor supervivencia. La identificación temprana de estos predictores descriptos podría ayudar a mejorar los resultados. Abstract in english Active infective endocarditis (IE) is a disease of low incidence that has showed changes in presentation, diagnosis and treatment options during the past decades. Despite these advances, mortality remains very high. Our goal was to analyze the characteristics of patients with active IE and their relationship with in-hospital mortality over 16 years. Between 1994 and 2010 we performed a prospective registry of 152 consecutive patients (64.5% male, age 45 ± 16 years) admit (more) ted with IE. Clinical characteristics, treatment and inpatient outcomes were analyzed. The most common causes of underlying heart disease were: congenital (21%) and rheumatic fever (13.2%). The reasons for hospitalization were fever (76.3%) and heart failure (40.1%). The infectious agent was identified in 69.7% of cases, and the most frequent was Streptococcus viridans. The echocardiogram showed vegetations in 80.9% of patients and 57.8% of them presented complications (the most frequent was heart failure) during hospitalization. Surgical treatment was indicated in 63.2% of cases, mainly due to heart failure. The overall hospital mortality was 30.2%. The presence of complications, requirement of surgical treatment and refractory heart failure were independent predictors of mortality whereas the single presence of vegetation showed better survival rate. The identification of these predictors could help to improve the outcomes in IE.
Abstract in spanish Introducción. Streptococcus pneumoniae es un agente comúnmente implicado en enfermedad invasora. Los macrólidos constituyen un tratamiento alternativo para las infecciones por S. pneumoniae resistente a los b-lactámicos. Sin embargo, la resistencia a macrólidos se ha incrementado a nivel mundial. Objetivo. Determinar la frecuencia de la resistencia a la eritromicina de S. pneumoniae en 15 años de vigilancia y caracterizar fenotípica y genotípicamente los aislamien (more) tos resistentes. Materiales y métodos. Se analizaron los datos demográficos de los pacientes, la sensibilidad antimicrobiana y los serotipos de los aislamientos resistentes a la eritromicina, recuperados entre 1994 y 2008. Se determinaron los fenotipos por la técnica del doble disco, y los genotipos, por PCR y PFGE. Todos los aislamientos se recuperaron de enfermedad invasiva y fueron proporcionados por los laboratorios nacionales de salud pública. Resultados. Se recuperaron 3.241 aislamientos invasores; 136 (4,2 %) presentaron resistencia a la eritromicina. La resistencia a la eritromicina se incrementó entre 1994-1996 y 2006-2008, de 2,4 % a 6,9 % en menores de 6 años y, de 3,3 % a 5,7 %, en adultos. Los serotipos más frecuentes fueron 6B (36,8 %), 14 (16,9 %) y 6A (17,6 %). El fenotipo constitutivo cMLSB se determinó en 87 aislamientos; 82 tenían el gen ermB. Elfenotipo M se determinó en 46; 45 tenían el gen mefA, tres aislamientos expresaron fenotipo inducible (iMLSB) y un aislamiento presentaba el gen ermB. Por PFGE, se determinó que 50 aislamientos estaban relacionados con clones internacionales, de los cuales, 58 % eran España6B ST90, 26 % eran España9V ST156, 8 % eran Colombia23F-ST338 y 8 % eran España23F-ST81. Conclusiones. Se observó incremento en la resistencia a la eritromicina, relacionada principalmente con el mecanismo de metilación ribosómica y con el clon España6B-ST90 que ha circulado en Colombia desde 1994. Abstract in english Introduction. Streptococcus pneumoniae is a commonly implicated agent in invasive disease. For infections of S. pneumoniae resistant to b-lactam, macrolides are an alternative treatment. However, resistance to macrolides has increased worldwide as well. Objective. The frequency of resistance to erythromycin was determined for S. pneumoniae over a 15-year surveillance period, and the resistant isolates were characterized phenotypically and genotypically. Materials and meth (more) ods. Demographic data of the patients, antimicrobial susceptibility and serotypes were analyzed for 3,241 S. pneumoniae isolates recovered between 1994 and 2008. The phenotypes were determined by the double-disc technique and genotypes by PCR (polymerase chain reaction) and PFGE (pulsed field gel electrophoresis). Isolates were recovered from invasive diseases and were provided by national public health laboratories. Results. Of the 3,241 isolates, 136 were resistant to erythromycin. In the 12-year period between 1994-1996 and 2006-2008, resistance in each 2-year sampling had increased from 2.4% to 6.9% in children under 6 years and from 3.3% to 5.7% in adults. The most common serotypes were 6B (36.8%), 14 (16.9%) and 6A (17.6%). Constitutive phenotype cMLSB was determined in 87 isolates; 82 of these expressed the ermB gene. Phenotype M was determined in 46 isolates; 45 had the mefA gene. An additional three isolates expressed the inducible phenotype (iMLSB), and one expressed the ermB gene. By PFGE, 50 of the isolates were found to be related to international clones--58% were Spain6B-ST90, 26% Spain9V-ST156, 8% Colombia23F-ST338 and 8% Spain23F-ST81. Conclusion. The increase in erythromycin resistance was primarily related to the mechanism of ribosomal methylation. More than half the cases were congeneric with the clone Spain6B-ST90 that has been circulating in Colombia since 1994.
Abstract in portuguese Com o objetivo de estudar os efeitos de probióticos no desempenho de frangos de corte consumindo dietas com farinhas de carne e ossos com diferentes contaminações bacterianas, foi realizado um experimento na Universidade Federal de Lavras, no qual foram utilizados 576 pintos da linhagem Hubbard, com um dia de idade, metade de cada sexo. O delineamento experimental foi inteiramente casualizado, num esquema fatorial 4 x 3 (rações e probióticos) com 4 repetições de 1 (more) 2 aves alojadas em baterias metálicas e o período experimental foi de 1 a 28 dias de idade. Os tratamentos foram constituídos de 4 rações, uma sem farinha de carne e ossos e com fosfato bicálcico (testemunha), e as outras três com farinhas de carne e ossos de alto (1,0 x 104), médio(4,5 x 103) e baixo (1,0 x 103) teor de contaminação bacteriana. Cada uma dessas rações foi fornecida sem probiótico, ou com um probiótico com cerca de três bilhões de células viáveis por grama, que tem como agentes ativos o Lactobacillus acidophilus, Streptococcus faecium e Sacharomices cerevisae, fornecido na ração na dose de 10 g/ton ou ainda com um probiótico que contém Enterococcus faecium, Lactobacillus acidófillus, Lactobacillus plantarum e Lactobacillus sp como agentes ativos, na concentração de 3 x 1010 ufc/g do produto, adicionado na água nas primeiras 24 horas de vida dos pintinhos, na proporção de 1,33 g/L de água. Observou-se pela análise da variância dos resultados que não houve efeito dos tratamentos (P>0,05) sobre o ganho de peso e consumo de ração e na conversão alimentar, para as aves que consumiram a ração com baixa contaminação. A inclusão de farinha de carne e ossos nas rações melhorou a conversão alimentar para as aves que receberam a ração com alta e média contaminação, independente do uso de probiótico. Verificaram-se redução nos casos de diarréia durante a primeira semana de vida dos pintinhos, com o uso de probióticos, e aumento na incidência de diarréia, quando se utilizou farinha de carne e ossos com médio e alto nível de contaminação bacteriana. Abstract in english Aiming to study the effects of probiotics on performance of broiler chickens fed on diets containing bone and meat meal with different levels of bacterial contamination, an experiment was carried out in the Federal University of Lavras . 576 one-day-old broiler chicken of the Hubbard line, of both sexes, were used. The experimental design was completely randomized, in a 4 X 3 scheme (4 rations and 3 probiotics) with 4 replications, being 12 birds per plot, housed in cages (more) . The treatments were made up of 4 rations, one with no meat meal and with bicalcic phosphate (check) and the other three with meat meal with high, medium and lower levels of contamination (1.0x104, 4.5x103 and 1.0x103 ufc/g), respectively. Each of these rations were fed: without probiotic; with a probiotic containing about 3 billion viable cells pergram of Lactobacillus acidophilus, Streptococcus faecium e Sacharomices cerevisae, at the a dose of 10 g/ton; and a probiotic containing Enterococcus faecium, Lactobacillus acidófillus, Lactobacillus plantarum e Lactobacillus sp., at the concentration of 3 X1010 ufc/g of this product, added to water (1.33 g/L) in the first 24 hours of chick's life. It was found that there was not any significant effects (P
Abstract in spanish Se realizó un estudio ambispectivo y descriptivo en 117 pacientes egresados vivos o fallecidos con el diagnóstico de meningoencefalitis bacteriana en los años de (2002 a 2006), en los Hospitales Provinciales "León Cuervo" y "Abel Santamaría". Para la validación estadística se aplicó la prueba estadística no paramétrica x², y el test de hipótesis de proporciones para grupos independientes, para un nivel de ajuste de a=0.05. La mayor parte de los pacientes con m (more) eningoencefalitis bacteriana aguda y subaguda se encontraba entre los 15 y los 59 años de edad, disminuyendo la frecuencia de la enfermedad a medida que avanza la edad, la mayor mortalidad se observó en los de 60 años o más, siendo este hecho altamente significativo. Los síntomas y signos más frecuentes fueron fiebre, cefalea, rigidez de nuca y alteraciones de la conciencia; la ausencia de fiebre, la presencia de vómitos, alteraciones de la conciencia, convulsiones, otros signos meníngeos, así como petequias, constituyeron signos de mal pronóstico. Las complicaciones más frecuentes resultaron ser edema cerebral, neumonía aguda nosocomial e insuficiencia respiratoria aguda no asociada al SIRPA, todas con diferencias estadísticas altamente significativas respecto a la probabilidad de morir por ellas. Los agentes etiológicos fueron, en orden decreciente, Streptococcus pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis, Enterobacter aerogenes, Neisseria meningitidis y Haemophilus influenzae. El cultivo resultó negativo en la mayoría de los casos que usaron antibioticoterapia previa al diagnóstico. Abstract in english A descriptive study was performed from 2002 _ 2006 in 117 patients with a bacterial meningoencephalitis diagnosis being discharged alive or death in "Abel Santamaría" or "Leon Cuervo Rubio" hospitals. The non _ parametric statistical X2 testing was used for the statistical validation as well as the hypothesis testing of ratios for independent groups, a fitted value of á=0.05. Most of patients with acute and sub acute bacterial meningoencephalitis were in 15 and 59 year (more) age range decreasing the frequency of the disease with the age advancing , the highest mortality rate was observed at 60 years old or over being considered very significant . The most predisposing factors were: otitis media, acute community pneumonia and sinusitis, some of them partially treated or not. Fever, headache, neck stiffness and consciousness disorders were the most frequent symptoms and signs and the absence of fever, the occurrence of vomits, consciousness disorders, convulsions, and other meningeal signs and petechiae were considered as a bad prognosis. The most frequent complications were cerebral edema, nosocomial acute pneumonia and acute respiratory failure no associated to SIRPA having all of them very significant statistical differences and leading to a probable death. The etiological agents were: Streptococcus pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis, Enterobacter aerogenes, Neisseria meningitides and Haemophilus influenzae. In most of cases given antibiotic therapy before diagnosis the culture was negative.
Phosphate-based glasses (PBGs) are excellent controlled delivery agents for antibacterial ions such as silver and gallium. The aim of this study was to assess the potential utility of novel PBGs combining both gallium and silver for use in periodontal therapy. To this end, an in vitro biofilm model with the putative periodontal pathogen, Porphyromonas gingivalis, and an initial colonizer, Streptococcus gordonii, was established. The effect of increasing calcium content in gallium-silver-doped PBG on the susceptibility of P. gingivalis was examined. A decrease in degradation rates (30.34, 25.19, 21.40 ?g mm(-2) h(-1)) with increasing PBG calciumcontent (10, 11, 12 mol.% respectively) was observed, correlating well with gallium and silver ion release and antimicrobial activity against planktonic P. gingivalis (approximately 5.4log(10) colony-forming units (CFU) reduction after 24h by the C10 glass compared with controls) and S. gordonii (total growth inhibition after 32h by C10, C11 and C12 glasses compared with controls). The most potent PBG (C10) was evaluated for its ability to inhibit the biofilm growth of P. gingivalis in a newly established constant-depth film fermentor model. The simultaneous release of silver and gallium from the glass reduced P. gingivalis biofilm growth with a maximum effect (1.92log(10) CFU reduction) after 168 h. Given the emergence of antibiotic-resistant bacteria and dearth of new antibiotics in development, the glasses, especially C10, would offer effective alternatives to antibiotics or may complement current therapies through controlled, localized delivery of gallium and silver ions at infected sites in the oral cavity. PMID:22314314
A number of research have proven that antimicrobial peptides are of greatest potential as a new class of antibiotics. Antimicrobial peptides and cell-penetrating peptides share some similar structure characteristics. In our study, a new peptide analog, APP (GLARALTRLLRQLTRQLTRA) from the cell-penetrating peptide ppTG20 (GLFRALLRLLRSLWRLLLRA), was identified simultaneously with the antibacterial mechanism of APP against Salmonella typhimurium and Streptococcus pyogenes. APP displayed potent antibacterial activity against Gram-negative and Gram-positive strains. The minimum inhibitory concentration was in the range of 2 to 4 ?M. APP displayed higher cell selectivity (about 42-fold increase) as compared to the parent peptide for it decreased hemolytic activity and increased antimicrobial activity. The calcein leakage from egg yolk L: -?-phosphatidylcholine (EYPC)/egg yolk L: -?-phosphatidyl-DL: -glycerol and EYPC/cholesterol vesicles demonstrated that APP exhibited high selectivity. The antibacterial mechanism analysis indicated that APP induced membrane permeabilization in a kinetic manner for membrane lesions allowing O-nitrophenyl-?-D: -galactoside uptake into cells and potassium release from APP-treated cells. Flow cytometry analysis demonstrated that APP induced bacterial live cell membrane damage. Circular dichroism, fluorescence spectra, and gel retardation analysis confirmed that APP interacted with DNA and intercalated into the DNA base pairs after penetrating the cell membrane. Cell cycle assay showed that APP affected DNA synthesis in the cell. Our results suggested that peptides derived from the cell-penetrating peptide have the potential for antimicrobial agent development, and APP exerts its antibacterial activity by damaging bacterial cell membranes and binding to bacterial DNA to inhibit cellular functions, ultimately leading to cell death. PMID:22923068
Streptococcus mutans, a major etiological agent of dental caries, frequently causes systemic disease, such as subacute bacterial endocarditis, if it enters the bloodstream. In this study, the production pathways of the proinflammatory cytokines, tumor necrosis factor-? (TNF-?) and interleukin-1? (IL-1?), induced by S. mutans in mouse macrophage were examined using a quantitative real-time polymerase chain reaction and an enzyme-linked immunosorbent assay. The S. mutans stimulated the expression of TNF-? and IL-1? mRNA at a multiplicity of infection of 1 : 100, which increased at 2 and 4 h, respectively, to 24 h. It also induced the production of high levels of the TNF-? and IL-1? proteins, which increased at 2 h and reached a peak at 4 and 24 h, respectively. Nuclear factor-?B (NF-?B) was activated and reached a maximum level 30 min after the S. mutans treatment. The expression of TNF-? and IL-1? mRNA and protein was suppressed by the treatment with pyrrolidine dithiocarbamate, an NF-?B inhibitor. The S. mutans-induced TNF-? expression was suppressed by the presence of SB203580, a p38 mitogen-activated protein (MAP) kinase inhibitor, or SP600125, a Jun N-terminal kinase (JNK) MAP kinase inhibitor. On the other hand, IL-1? expression was inhibited by extracellular signal-regulated kinase (ERK)/p38/JNK MAP kinase inhibitor pretreatment. In addition, TNF-? production was suppressed more in the Toll-like receptor 2(-/-) (TLR2(-/-)) macrophages than in the TLR4(-/-) macrophages, whereas IL-1? production was suppressed more in the TLR4(-/-) macrophages than in the TLR2(-/-) macrophages. These results show that S. mutans stimulates the production of TNF-? and IL-1? in the mouse macrophage cell line, RAW 264.7, by activating ERK/p38/JNK, and NF-?B through TLR2 and TLR4, respectively. PMID:22520385
Background: More than 5 million Americans are bitten by animals, usually dogs, annually. Bite patients comprise ?1 % of all emergency department visits (300,000/year) and approximately 10,000 require hospitalization and IV antibiotics. Ceftaroline is the bioactive component of the prodrug Ceftaroline fosamil, which is FDA approved for acute bacterial skin and skin structure infections (ABSSSI) including those containing methicillin-resistant Staphylococcus aureus (MRSA). There are no in vitro data about the activity of ceftaroline vs. Pasteurella multocida ssp. multocida, and ssp. septica, other Pasteurella spp, or other bite wound isolates. We therefore studied the in vitro activity of ceftaroline vs. 243animal bite isolates.Methods: MICs were determined using the broth microdilution method according to CLSI guidelines. Comparator drugs included cefazolin, ceftriaxone, ertapenem, ampicillin-sulbactam, azithromycin, doxycycline and sulfamethoxazole-trimethoprim.Results: Ceftaroline was the most active agent against all 5 Pasteurella species, including P. multocida ssp. multocida and ssp. septica with a maximum MIC of ?0.008 ?g/mL, more active than ceftriaxone and ertapenem (MIC 90s, ? .015 ?g/ml) and more active than cefazolin (MIC(90), 0.5 ?g/ml) doxycycline (0.125 ?g/ml), azithromycin (0.5 ?g/ml), ampicillin-sulbactam (0.125 ?g/ml) and SXT (0.125 ?g/ml). Ceftaroline was also very active against all S. aureus (MIC(90), 0.125 ?g/ml), other Staphylococcus and Streptococcus species with a maximum MIC of 0.125 ?g/ml against all bite isolates tested.Conclusions: Ceftaroline has potential clinical utility against infections involving P. multocida, other Pasteurella species and aerobic gram-positive isolates including S. aureus. PMID:23027193
Toll-Like Receptor-Targeting Immunotherapy for Oral Cancer
It is important to augment the anti-cancer host response in cancer treatment. Recent studies have suggested that the signaling that occurs via the Toll-like receptors (TLRs), which are newly identified receptor molecules recognizing many pathogens, are involved in the induction of anti-cancer immunity. OK-432, a penicillin-killed and lyophilized preparation of Streptococcus pyogenes, is being successfully used as an immunotherapeutic agent in many types of malignancies. However, the molecular mechanisms of OK-432, a whole bacterial preparation, and the active components which make it effective against cancer, remain uncertain. We have succeeded in isolating the active component of OK-432 (lipoteichoic acid-related molecule, OK-PSA) by affinity chromatography of a butanol extract of OK-432 on the CNBr-activated sepharose 4B bound TS-2 monoclonal antibody that neutralizes the interferon (IFN)-?-inducing activity of OK-432. OK-PSA induced Th1-type cytokines both in human and in mice, and elicited an anti-cancer effect in tumor-bearing mice via TLR4. Furthermore, our clinical study revealed that TLR4 signaling is intimately involved in the anti-cancer effect achieved by OK-432 in patients with oral cancer. We elucidated that OK-432 is first captured and digested by phagocytes, such as dendritic cells and macrophages, and then its active component, OK-PSA, which is released from the phagocytes, stimulates TLR4 signaling. It is strongly suggested that OK-PSA is the molecule most responsible for the anti-cancer effect of OK-432, and that TLR4 may be a definite molecular target for cancer immunotherapy with OK-432/OK-PSA.
Clin Microbiol Infect 2012; 18: E452-E458 ABSTRACT: EUCAST breakpoint criteria are being adopted by automatic antimicrobial susceptibility testing systems. The accuracy of the Phoenix Automated System in combination with 2012 EUCAST breakpoints against recent clinical isolates was evaluated. A total of 697 isolates (349 Enterobacteriaceae, 113 Pseudomonas spp., 25 Acinetobacter baumannii, 11 Stenotrophomonas maltophilia, 95 Staphylococcus aureus, 6 coagulase negative staphylococci, 77 enterococci and 21 Streptococcus pneumoniae) with defined resistance phenotypes and well-characterized resistance mechanisms recovered in Spain (n?=?343) and Italy (n?=?354) were tested. Comparator antimicrobial susceptibility testing data were obtained following CLSI guidelines. Experimental agreement (EA), defined as MIC agreement?±1 log(2) dilution, category agreement (CA) and relative discrepancies (minor (mD), major (MD) and very major discrepancies (VMD)) were determined. The overall EA and CA for all organism-antimicrobial agent combinations (n?=?6.294) were 97.3% and 95.2%, respectively. mD, MD and VMD were 4.7%, 1.3% and 2.7%, all of them in agreement with the ISO (ISO20776-2:2007) acceptance criteria for assessment of susceptibility testing devices. VMD were mainly observed in amoxicillin-clavulanate and cefuroxime in Enterobacteriaceae and gentamicin in Pseudomonas aeruginosa, whereas MD were mainly observed in amoxicillin-clavulante in Enterobacteriaceae. mD were mainly observed in Enterobacteriaceae but distributed in different antimicrobials. For S. aureus and enterococci relative discrepancies were low. The Phoenix system showed accuracy assessment in accordance with the ISO standards when using EUCAST breakpoints. Inclusion of EUCAST criteria in automatic antimicrobial susceptibility testing systems will facilitate the implementation of EUCAST breakpoints in clinical microbiology laboratories. PMID:22909279
Nucleocytoplasmic transport: the soluble phase
Background Glycerol monolaurate (GML) is an antimicrobial agent that has potent activity against gram-positive bacteria. This study examines GML antibacterial activity in comparison to lauric acid, in broth cultures compared to biofilm cultures, and against a wide range of gram-positive, gram-negative, and non-gram staining bacteria. Methodology/Principal Findings GML is ?200 times more effective than lauric acid in bactericidal activity, defined as a ?3 log reduction in colony-forming units (CFU)/ml, against Staphylococcus aureus and Streptococcus pyogenes in broth cultures. Both molecules inhibit superantigen production by these organisms at concentrations that are not bactericidal. GML prevents biofilm formation by Staphylococcus aureus and Haemophilus influenzae, as representative gram-positive and gram-negative organisms, tested in 96 well microtiter plates, and simultaneously is bactericidal for both organisms in mature biofilms. GML is bactericidal for a wide range of potential bacterial pathogens, except for Pseudomonas aeruginosa and Enterobacteriaceae. In the presence of acidic pH and the cation chelator ethylene diamine tetraacetic acid, GML has greatly enhanced bactericidal activity for Pseudomonas aeruginosa and Enterobacteriaceae. Solubilization of GML in a nonaqueous delivery vehicle (related to K-Y Warming®) enhances its bactericidal activity against S. aureus. Both R and S, and 1 and 2 position lauric acid derivatives of GML exhibit bactericidal activity. Despite year-long passage of Staphylococcus aureus on sub-growth inhibitory concentrations of GML (0.5 x minimum bactericidal concentration), resistance to GML did not develop. Conclusions/Significance GML may be useful as a broad-spectrum human or animal topical microbicide and may be useful as an environmental surface microbicide for management of bacterial infections and contamination. PMID:9759490
Abstract in english This study was conducted to evaluate the activity of azithromycin in comparison to 12 other antibacterial agents against recent isolates obtained consecutively from patients with respiratory tract or skin infections, from January to July, 2000. A total of 717 Gram-positive cocci were analyzed in this study and the following species were studied: Staphylococcus aureus (n=576), beta-hemolytic streptococci ( n=115), and Streptococcus pneumoniae (n=26). Susceptibility testing (more) was carried out by the disk diffusion method and interpreted according to NCCLS breakpoints. The activity of azithromycin was compared to erythromycin, clindamycin, chloramphenicol, ciprofloxacin, ofloxacin, oxacillin, penicillin, ceftriaxone, tetracycline, trimethoprim/sulfamethoxazole, teicoplanin, and vancomycin. Of the 26 S. pneumoniae isolates recovered from the respiratory tract, 5 (19.2%) were intermediate resistant to penicillin. All of these strains were susceptible to chloramphenicol, ofloxacin, and vancomycin, and 24 (92%) were also susceptible to azithromycin, clindamycin, and erythromycin. Among the 67 beta-hemolytic streptococci strains isolated from the respiratory tract, 66 (99%) were susceptible to azithromycin, erythromycin, clindamycin, and ofloxacin. All 48 beta-hemolytic streptococci strains isolated from skin were susceptible to azithromycin and clindamycin, 47 (98%) were susceptible to erythromycin, and 46 (96%) were susceptible to ofloxacin. Of the 576 strains of S. aureus, 253 (43.9%) were isolated from the respiratory tract and 323 (56.1%) from skin. Among S. aureus isolates from the respiratory tract and skin, 46 (18%) and 78 (24%), respectively were resistant to oxacillin. Isolates from the respiratory tract and skin showed the same percentage of resistance (36%) to azithromycin. These in vitro results suggest that azithromycin can be a therapeutic option for treatment of infections caused by these bacteria since the newer macrolides have several distinct advantages over erytromycin including improved oral bioavailability, longer half-life allowing once or twice daily administration, higher tissue concentrations and less gastrointestinal adverse effects.
Rituximab and intravenous immune globulin for desensitization during renal transplantation
Bacterial adhesion is often a prerequisite for infection, and host cell surface carbohydrates play a major role as adhesion receptors. Streptococci are a leading cause of infectious diseases. However, only few carbohydrate-specific streptococcal adhesins are known. Streptococcus suis is an important pig pathogen and a zoonotic agent causing meningitis in pigs and humans. In this study, we have identified an adhesin that mediates the binding of S. suis to galactosyl-?1–4-galactose (Gal?1–4Gal)-containing host receptors. A functionally unknown S. suis cell wall protein (SSU0253), designated here as SadP (streptococcal adhesin P), was identified using a Gal?1–4Gal-containing affinity matrix and LC-ESI mass spectrometry. Although the function of the protein was not previously known, it was recently identified as an immunogenic cell wall protein in a proteomic study. Insertional inactivation of the sadP gene abolished S. suis Gal?1–4Gal-dependent binding. The adhesin gene sadP was cloned and expressed in Escherichia coli. Characterization of its binding specificity showed that SadP recognizes Gal?1–4Gal-oligosaccharides and binds its natural glycolipid receptor, GbO3 (CD77). The N terminus of SadP was shown to contain a Gal?1-Gal-binding site and not to have apparent sequence similarity to other bacterial adhesins, including the E. coli P fimbrial adhesins, or to E. coli verotoxin or Pseudomonas aeruginosa lectin I also recognizing the same Gal?1–4Gal disaccharide. The SadP and E. coli P adhesins represent a unique example of convergent evolution toward binding to the same host receptor structure. PMID:18635429
Bacterial adhesion is often a prerequisite for infection, and host cell surface carbohydrates play a major role as adhesion receptors. Streptococci are a leading cause of infectious diseases. However, only few carbohydrate-specific streptococcal adhesins are known. Streptococcus suis is an important pig pathogen and a zoonotic agent causing meningitis in pigs and humans. In this study, we have identified an adhesin that mediates the binding of S. suis to galactosyl-?1-4-galactose (Gal?1-4Gal)-containing host receptors. A functionally unknown S. suis cell wall protein (SSU0253), designated here as SadP (streptococcal adhesin P), was identified using a Gal?1-4Gal-containing affinity matrix and LC-ESI mass spectrometry. Although the function of the protein was not previously known, it was recently identified as an immunogenic cell wall protein in a proteomic study. Insertional inactivation of the sadP gene abolished S. suis Gal?1-4Gal-dependent binding. The adhesin gene sadP was cloned and expressed in Escherichia coli. Characterization of its binding specificity showed that SadP recognizes Gal?1-4Gal-oligosaccharides and binds its natural glycolipid receptor, GbO(3) (CD77). The N terminus of SadP was shown to contain a Gal?1-Gal-binding site and not to have apparent sequence similarity to other bacterial adhesins, including the E. coli P fimbrial adhesins, or to E. coli verotoxin or Pseudomonas aeruginosa lectin I also recognizing the same Gal?1-4Gal disaccharide. The SadP and E. coli P adhesins represent a unique example of convergent evolution toward binding to the same host receptor structure. PMID:21908601
Special attention has been focused on the recent problem of pediatric acute otitis media. The increase in the number of pediatric patients with intractable acute otitis media has been a serious problem in the clinical setting of ENT clinics and hospitals. Such a change in the clinical figures of otitis media may be due to the social environment, including the tendency for more very young children to be looked after at nurseries, and the increase in drug-resistant bacteria. In the clinical guidelines for the treatment of pediatric acute otitis media, published in 2006 and revised in 2009, a classification of severity according to scoring of symptoms and tympanic membrane findings was proposed and a severity-oriented treatment algorithm was recommended. In response to the proliferation of drug-resistant bacteria, we have also emphasized the importance of the proper use of antimicrobials and have promoted a correct assessment of the clinical efficacy of various antimicrobial agents according to the scoring system recommended by the guidelines. In this study, we employed this severity classification by the scoring system to examine the usefulness and bacteriological efficacy of tosufloxacin (TFLX) fine granules (6 mg/kg bid), a novel pediatric quinolone antimicrobial, in 106 children aged 15 or under diagnosed with moderate or severe acute pediatric otitis media. We obtained the following results. The clinical response rate to TFLX was 98.1% (104/106) according to the score-oriented evaluation and 97.2% (103/106) as conventionally judged by the treating physicians. Bacterial pathogens detected in this study were Haemophilus influenzae 37.7% (40/106), Streptococcus pneumoniae 32.1% (34/106) and Moraxella catarrhalis 6.6% (7/106). At the time of completion of TFLX administration, the rate of bacterial elimination was 95.8% (69/72). Only one patient experienced mild diarrhea as an adverse drug reaction.
Mevalonate diphosphate decarboxylase (MDD) catalyzes the final step of the mevalonate pathway, the Mg(2+)-ATP dependent decarboxylation of mevalonate 5-diphosphate (MVAPP), producing isopentenyl diphosphate (IPP). Synthesis of IPP, an isoprenoid precursor molecule that is a critical intermediate in peptidoglycan and polyisoprenoid biosynthesis, is essential in Gram-positive bacteria (e.g., Staphylococcus, Streptococcus, and Enterococcus spp.), and thus the enzymes of the mevalonate pathway are ideal antimicrobial targets. MDD belongs to the GHMP superfamily of metabolite kinases that have been extensively studied for the past 50 years, yet the crystallization of GHMP kinase ternary complexes has proven to be difficult. To further our understanding of the catalytic mechanism of GHMP kinases with the purpose of developing broad spectrum antimicrobial agents that target the substrate and nucleotide binding sites, we report the crystal structures of wild-type and mutant (S192A and D283A) ternary complexes of Staphylococcus epidermidis MDD. Comparison of apo, MVAPP-bound, and ternary complex wild-type MDD provides structural information about the mode of substrate binding and the catalytic mechanism. Structural characterization of ternary complexes of catalytically deficient MDD S192A and D283A (k(cat) decreased 10(3)- and 10(5)-fold, respectively) provides insight into MDD function. The carboxylate side chain of invariant Asp(283) functions as a catalytic base and is essential for the proper orientation of the MVAPP C3-hydroxyl group within the active site funnel. Several MDD amino acids within the conserved phosphate binding loop ("P-loop") provide key interactions, stabilizing the nucleotide triphosphoryl moiety. The crystal structures presented here provide a useful foundation for structure-based drug design. PMID:22734632
Group A Streptococcus (GAS) is a common causative agent of pharyngitis, but the role of GAS in otitis media is underappreciated. In this study, we sought to test the hypothesis that GAS colonizes the middle ear and establishes itself in localized, three-dimensional communities representative of biofilms. To test this hypothesis, the middle ears of chinchillas were infected with either a strain of GAS capable of forming biofilms in vitro (MGAS5005) or a strain deficient in biofilm formation due to the lack of the transcriptional regulator Srv (MGAS5005 ?srv). Infection resulted in the formation of large, macroscopic structures within the middle ears of MGAS5005- and MGAS5005 ?srv-infected animals. Plate counts, scanning electron microscopy, LIVE/DEAD staining, and Gram staining revealed a difference in the distributions of MGAS5005 versus MGAS5005 ?srv in the infected samples. High numbers of CFU of MGAS5005 ?srv were isolated from the middle ear effusion, and MGAS5005 ?srv was found randomly distributed throughout the excised macroscopic structure. In contrast, MGAS5005 was found in densely packed microcolonies indicative of biofilms within the excised material from the middle ear. CFU levels of MGAS5005 from the effusion were significantly lower than that of MGAS5005 ?srv early during the course of infection. Allelic replacement of the chromosomally encoded streptococcal cysteine protease (speB) in the MGAS5005 ?srv background restored biofilm formation in vivo. Interestingly, our results suggest that GAS naturally forms a biofilm during otitis media but that biofilm formation is not required to establish infection following transbullar inoculation of chinchillas. PMID:20805338
Bad bugs, no drugs: no ESKAPE! An update from the Infectious Diseases Society of America
Moraxella catarrhalis is a Gram negative bacterium and a leading causative agent of otitis media (OM) in children. Several recent reports have provided strong evidence for an association between toll like receptors and OM. It has been found that both Streptococcus pneumoniae and nontypeable Haemophilus influenzae activate host protective immune responses through toll like receptors (TLRs), however, the precise mechanism by which Moraxella catarrhalis initiates the host immune response is currently unknown. In this report, using murine macrophages generated from a series of knock-out mice, we have demonstrated that M. catarrhalis lipooligosaccharide (LOS) and either heat killed or live bacteria are recognized by one or more TLRs. LOS activates the host immune response through a membrane bound CD14-TLR4 complex, while both heat killed and live M.cat require recognition by multiple toll like receptors such as TLR2, TLR4 and TLR9 without the requirement of CD14. We have also shown that M.cat stimuli are capable of triggering the host innate immune response by both MyD88- and TRIF- dependent signaling pathways. We further showed that M.cat induced activation of mitogen activated protein kinase (MAPK) is essential in order to achieve optimal secretion of pro-inflammatory cytokine TNF-?. We finally showed that TLR4 mutant C3H/HeJ mice produce significantly lower levels of pro-inflammatory cytokines TNF-? and IL-6 in vivo, An increased bacterial loads at 12 and 24 hours (P<0.001) in their lungs upon challenge with live M.cat in an aerosol chamber compared to wild-type (WT) control mice. These data suggest that TLRs are crucial for an effective innate immune response induced by M.cat. The results of these studies contribute to an increased understanding of molecular mechanism and possible novel treatment strategies for diseases caused by M.cat by specifically targeting TLRs and their signaling pathways. PMID:19035777
Moraxella catarrhalis is a gram negative bacterium and a leading causative agent of otitis media (OM) in children. Several recent reports have provided strong evidence for an association between toll like receptors and OM. It has been found that both Streptococcus pneumoniae and nontypeable Haemophilus influenzae activate host protective immune responses through toll like receptors (TLRs), however, the precise mechanism by which Moraxella catarrhalis initiates the host immune response is currently unknown. In this report, using murine macrophages generated from a series of knock-out mice, we have demonstrated that M. catarrhalis lipooligosaccharide (LOS) and either heat killed or live bacteria are recognized by one or more TLRs. LOS activates the host immune response through a membrane bound CD14-TLR4 complex, while both heat killed and live M.cat require recognition by multiple toll like receptors such as TLR2, TLR4 and TLR9 without the requirement of CD14. We have also shown that M.cat stimuli are capable of triggering the host innate immune response by both MyD88- and TRIF- dependent signaling pathways. We further showed that M.cat induced activation of mitogen activated protein kinase (MAPK) is essential in order to achieve optimal secretion of pro-inflammatory cytokine TNF-?. We finally showed that TLR4 mutant C3H/HeJ mice produce significantly lower levels of pro-inflammatory cytokines TNF-? and IL-6 in vivo, An increased bacterial loads at 12 and 24 hours (P<0.001) in their lungs upon challenge with live M.cat in an aerosol chamber compared to wild-type (WT) control mice. These data suggest that TLRs are crucial for an effective innate immune response induced by M.cat. The results of these studies contribute to an increased understanding of molecular mechanism and possible novel treatment strategies for diseases caused by M.cat by specifically targeting TLRs and their signaling pathways. PMID:22662179
The fight against antibiotic resistance is one of the most significant challenges to public health of our time. The inevitable development of resistance following the introduction of novel antibiotics has led to an urgent need for the development of new antibacterial drugs with new mechanisms of action that are not susceptible to existing resistance mechanisms. One such compound is HAMLET, a natural complex from human milk that kills Streptococcus pneumoniae (the pneumococcus) using a mechanism different from common antibiotics and is immune to resistance-development. In this study we show that sublethal concentrations of HAMLET potentiate the effect of common antibiotics (penicillins, macrolides, and aminoglycosides) against pneumococci. Using MIC assays and short-time killing assays we dramatically reduced the concentrations of antibiotics needed to kill pneumococci, especially for antibiotic-resistant strains that in the presence of HAMLET fell into the clinically sensitive range. Using a biofilm model in vitro and nasopharyngeal colonization in vivo, a combination of HAMLET and antibiotics completely eradicated both biofilms and colonization in mice of both antibiotic-sensitive and resistant strains, something each agent alone was unable to do. HAMLET-potentiation of antibiotics was partially due to increased accessibility of antibiotics to the bacteria, but relied more on calcium import and kinase activation, the same activation pathway HAMLET uses when killing pneumococci by itself. Finally, the sensitizing effect was not confined to species sensitive to HAMLET. The HAMLET-resistant respiratory species Acinetobacter baumanii and Moraxella catarrhalis were all sensitized to various classes of antibiotics in the presence of HAMLET, activating the same mechanism as in pneumococci. Combined these results suggest the presence of a conserved HAMLET-activated pathway that circumvents antibiotic resistance in bacteria. The ability to activate this pathway may extend the lifetime of the current treatment arsenal. PMID:22905269
Ceftaroline fosamil, the prodrug form of the active metabolite ceftaroline, is a new broad-spectrum parenteral cephalosporin with antibacterial activity against the prevalent respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus. Bacterial resistance surveillance (5330 isolates) was conducted in the United States between 2008 and 2010 to assess the in vitro activity of ceftaroline and comparator antibacterial agents against invasive respiratory isolates of S. pneumoniae (3329 isolates), H. influenzae (1545 isolates), and M. catarrhalis (456 isolates). All organisms were cultured from patient infections in 71 US hospital laboratories and were submitted to a central reference monitor for broth microdilution testing by Clinical and Laboratory Standards Institute reference methods. Against S. pneumoniae, ceftaroline inhibited 98.7% of strains at the susceptible breakpoint of ? 0.25 µg/mL (50% minimum inhibitory concentration [MIC(50)], 0.01 µg/mL; 90% MIC [MIC(90)], 0.12 µg/mL) and was 16-fold more active than ceftriaxone (MIC(90), 2 µg/mL). Among 70 ceftriaxone-resistant pneumococcal isolates, all were inhibited by ? 0.5 µg/mL of ceftaroline. Haemophilus influenzae (MIC(50), ? 0.008 µg/mL; MIC(90), 0.015 µg/mL) and M. catarrhalis (MIC(50), 0.06 µg/mL; MIC(90), 0.12 µg/mL) were very susceptible to ceftaroline regardless of ?-lactamase production. Whereas the high-level of activity of ceftaroline was maintained against S. pneumoniae and H. influenzae from 2008 through 2010, increased rates of nonsusceptibility were observed for amoxicillin/clavulanate, erythromycin, and levofloxacin among S. pneumoniae and for trimethoprim/sulfamethoxazole and azithromycin among H. influenzae. In summary, ceftaroline resistance surveillance (Assessing Worldwide Antimicrobial Resistance Evaluation [AWARE] Program) in the United States (2008-2010) documented in vitro sustained potency and spectrum against Gram-positive and Gram-negative pathogens known to cause community-acquired bacterial pneumonia. PMID:22903951
The extracytoplasmic function (ECF) sigma factors
The fight against antibiotic resistance is one of the most significant challenges to public health of our time. The inevitable development of resistance following the introduction of novel antibiotics has led to an urgent need for the development of new antibacterial drugs with new mechanisms of action that are not susceptible to existing resistance mechanisms. One such compound is HAMLET, a natural complex from human milk that kills Streptococcus pneumoniae (the pneumococcus) using a mechanism different from common antibiotics and is immune to resistance-development. In this study we show that sublethal concentrations of HAMLET potentiate the effect of common antibiotics (penicillins, macrolides, and aminoglycosides) against pneumococci. Using MIC assays and short-time killing assays we dramatically reduced the concentrations of antibiotics needed to kill pneumococci, especially for antibiotic-resistant strains that in the presence of HAMLET fell into the clinically sensitive range. Using a biofilm model in vitro and nasopharyngeal colonization in vivo, a combination of HAMLET and antibiotics completely eradicated both biofilms and colonization in mice of both antibiotic-sensitive and resistant strains, something each agent alone was unable to do. HAMLET-potentiation of antibiotics was partially due to increased accessibility of antibiotics to the bacteria, but relied more on calcium import and kinase activation, the same activation pathway HAMLET uses when killing pneumococci by itself. Finally, the sensitizing effect was not confined to species sensitive to HAMLET. The HAMLET-resistant respiratory species Acinetobacter baumanii and Moraxella catarrhalis were all sensitized to various classes of antibiotics in the presence of HAMLET, activating the same mechanism as in pneumococci. Combined these results suggest the presence of a conserved HAMLET-activated pathway that circumvents antibiotic resistance in bacteria. The ability to activate this pathway may extend the lifetime of the current treatment arsenal. PMID:12073657
Role of VltAB, an ABC transporter complex, in viologen tolerance in Streptococcus mutans.
Streptococcus mutans, a Gram-positive organism, is the primary causative agent in the formation of dental caries in humans. To persist in the oral cavity, S. mutans must be able to tolerate rapid environmental fluctuations and exposure to various toxic chemicals. However, the mechanisms underlying the ability of this cariogenic pathogen to survive and proliferate under harsh environmental conditions remain largely unknown. Here, we wanted to understand the mechanisms by which S. mutans withstands exposure to methyl viologen (MV), a quaternary ammonium compound (QAC) that generates superoxide radicals in the cell. To elucidate the essential genes for MV tolerance, screening of ?3,500 mutants generated by ISS1 mutagenesis, revealed 15 MV-sensitive mutants. Among them, five and four independent insertions had occurred in SMU.905 and SMU.906 genes, respectively. These two genes are appeared to be organized in an operon and encode a putative ABC transporter complex; we designated the genes as vltA and vltB, for viologen transporter. To verify our results, vltA was deleted by using an antibiotic resistance marker; the mutant was just as sensitive to MV as the ISS1 insertion mutants. Furthermore, vltA and vltB mutants were also sensitive to other viologen compounds such as benzyl and ethyl viologens. Complementation assays were also carried out to confirm the role of VltA and VltB in viologen tolerance. Sensitivity to various drugs, including a wide range of QACs, was evaluated. It appears that a functional VltA is also required for full resistance toward acriflavin, ethidium bromide, and safranin; all are well-known QACs. These results indicate that VltA/B constitute a heterodimeric multidrug efflux pump of the ABC family. BLAST-P analysis suggests that homologs of VltA/B are widely present in streptococci, enterococci, and other important Gram-positive pathogens. PMID:21282456
Role of VltAB, an ABC Transporter Complex, in Viologen Tolerance in Streptococcus mutans? †
Streptococcus mutans, a Gram-positive organism, is the primary causative agent in the formation of dental caries in humans. To persist in the oral cavity, S. mutans must be able to tolerate rapid environmental fluctuations and exposure to various toxic chemicals. However, the mechanisms underlying the ability of this cariogenic pathogen to survive and proliferate under harsh environmental conditions remain largely unknown. Here, we wanted to understand the mechanisms by which S. mutans withstands exposure to methyl viologen (MV), a quaternary ammonium compound (QAC) that generates superoxide radicals in the cell. To elucidate the essential genes for MV tolerance, screening of ?3,500 mutants generated by ISS1 mutagenesis, revealed 15 MV-sensitive mutants. Among them, five and four independent insertions had occurred in SMU.905 and SMU.906 genes, respectively. These two genes are appeared to be organized in an operon and encode a putative ABC transporter complex; we designated the genes as vltA and vltB, for viologen transporter. To verify our results, vltA was deleted by using an antibiotic resistance marker; the mutant was just as sensitive to MV as the ISS1 insertion mutants. Furthermore, vltA and vltB mutants were also sensitive to other viologen compounds such as benzyl and ethyl viologens. Complementation assays were also carried out to confirm the role of VltA and VltB in viologen tolerance. Sensitivity to various drugs, including a wide range of QACs, was evaluated. It appears that a functional VltA is also required for full resistance toward acriflavin, ethidium bromide, and safranin; all are well-known QACs. These results indicate that VltA/B constitute a heterodimeric multidrug efflux pump of the ABC family. BLAST-P analysis suggests that homologs of VltA/B are widely present in streptococci, enterococci, and other important Gram-positive pathogens.
A comparative study of 890 patients with community-acquired pneumonia requiring hospitalization in a community hospital was performed. The patients were divided into an elderly patient group and a non-elderly patient group. The elderly patients with community-acquired pneumonia exhibited frequent atypical symptoms such as dyspnea, consciousness disturbance and complication of shock, and also were frequently in a poor nutritional condition. The causative microorganism was isolated in 40.8% of the elderly patients and in 44.0% of the non-elderly patients. Polymicrobial agents were detected frequently in the elderly patients. Streptococcus pneumoniae (19.4%), MSSA (16.8%), Klebsiella pneumoniae (15.1%) and Haemophilus influenzae (15.0%) were frequently isolated from the sputum of the elderly patients, while Mycoplasma pneumoniae (25.2%), H. influenzae (15.0%), S. pneumoniae (12.2%) and MSSA (10.2%) were frequently isolated from that of the non-elderly patients. Regarding treatment with antibiotics, therapy with a single antibiotic therapy, such as cephem or carbapenem was carried out for the elderly patients, while new quinolone or tetracycline was administered to the non-elderly patients. Although the treatment with antibiotics was adequate according to the guidelines of the American Thoracic Society, the prognosis was poor; i.e.) in the elderly patients an efficacy rate of 74.3% and a mortality rate of 9.5%. In the non-elderly patients, the prognosis was good; i.e.) an efficacy rate of 88.0% and a mortality rate of 1.7%. These results suggest that the most important factors affecting the prognosis were the general condition of elderly patients and delay in an adequate diagnosis and treatment because of atypical clinical findings. PMID:10695294
Abstract in spanish La neumonía adquirida en la comunidad es uno de los principales problemas de salud en niños. El Streptococcus pneumoniae es el microorganismo bacteriano más importante en todas las edades. Las bacterias gram negativas son una causa poco frecuente de esta entidad y cuando se presentan, generalmente están relacionadas con factores de riesgo como la inmunosupresión, hospitalizaciones y antibioticoterapia prolongada, procedimientos quirúrgicos repetidos y uso prolongado (more) de ventilación mecánica invasiva y otros dispositivos como catéteres centrales y sondas. Dentro de este grupo de bacterias, la Pseudomonas aeruginosa es la tercera en frecuencia como causa de neumonía y sepsis adquiridas en la comunidad. Su infección está descrita ampliamente a nivel nosocomial. Es muy poco usual que se adquiera en la comunidad y más raro aún en pacientes que no tienen factores de riesgo para infección por este germen. Se presenta el caso de una paciente con neumonía necrotizante y empiema por neumococo y pseudomonas adquiridos en la comunidad de forma simultánea, en la cual no se lograron evidenciar factores predisponentes Abstract in english Community acquired Pneumonia is one of the main health problems in children. S. pneumoniae is the most important bacterial microorganism at any age. Gram negative bacteria are a rare cause of this entity and when present, they usually are related with several risk factors like immunocompromised host, prolonged hospitalization and antimicrobial therapy, repeated surgical interventions, prolonged use of invasive mechanical ventilation and other medical invasive devices. In (more) this group of bacteria, Pseudomonas aeruginosa is the third in order of frequency to cause pneumonia and sepsis in the community setting. It's more widely known as a nosocomial agent. It's very unusual to be community acquired and even rarer in patients without risk factors for infection by this pathogen. In this paper we describe the case of a girl with both community acquired Pneumococcal and Pseudomonas necrotizing pneumonia and empyema at the same time, without any evidence of a predisposing factor.
[Bacterial susceptibility testings of the lower airways of diseased dogs].
Objective: In this retrospective study over 5 years the bacterial flora of the deep airways of diseased dogs was sampled using bronchioalveolar lavage and its in-vitro susceptibility to numerous antimicrobial agents was analysed. Material and methods: Susceptibility testing of bacterial isolates from 84 dogs performed from 2004 to 2009 were evaluated and compared to data collected in 1999/2000. Results: The 99 bacterial isolates comprised Pasteurella spp. (27.3%), Bordetella bronchiseptica (20.2%), Staphylococcus spp. (18.2%), Escherichia coli (15.2%), Klebsiella spp. (8.1%), Pseudomonas spp. (7.0%), and Streptococcus spp. (4.0%). Lavage samples of eight dogs revealed simultaneous occurrence of more than one species. The majority of the tested Bordetella bronchiseptica-isolates were susceptible to fluoroquinolones as well as tetracycline, doxycycline and polymyxin B. The number of amoxicillin/clavulanic acid- and chloramphenicol-resistant isolates decreased compared to 1999/2000. The increase of chloramphenicol-susceptible isolates was statistically significant. The tested Staphylococcus-isolates revealed a susceptibility to fluoroquinolones, amoxicillin, cephalexin, doxycycline, and polymyxin B. Compared to the earlier study, a major portion exhibited susceptibility to chloramphenicol and tetracycline. None of the Klebsiella spp. tested in 1999/2000 was resistant to enrofloxacin, whereas only 62.5% of the isolates examined during 2004-2009 were susceptible. A susceptibility of all tested Klebsiella -isolates was detectable with respect to polymyxin B. Regarding E.coli , none of the tested antibiotics revealed an in-vitro activity against all of the tested isolates. The increase of amoxicillin/clavulanic acid-resistant isolates was statistically significant. Conclusion and clinical relevance: The study demonstrates the benefits of bronchioalveolar lavage as a diagnostic tool to ensure a responsible utilisation of antibiotics. Most of the tested bacterial isolates were susceptible to fluoroquinolones. PMID:23076014
Background:? Infectious agents, especially Streptococcus sanguinis (S. sanguinis) and herpes simplex virus, have long been postulated to be major triggering factors for Behçet's disease (BD). Objectives:? The aim of this study was to identify an anti-S. sanguinis antigen reacting with serum IgA antibody in BD patients. Methods:? We detected a target protein by proteomics analysis and evaluated serum IgA reactivity of 100 BD patients against the identified streptococcal target protein and human hnRNP A2/B1. Homologous epitope sequences between the streptococcal target protein and human hnRNP A2/B1 were also evaluated. Results:? Four protein bands were detected by immunoprecipitation, and chaperonin GroEL was identified by a proteomics analysis. Reactivity of serum IgA against recombinant S. sanguinis GroEL was detected in 77 of 100 BD patients (77%) and in 21 of 70 healthy controls (30%). In addition, reactivity of serum IgA against human recombinant hnRNP A2/B1 was present in 79 of 100 BD patients (79%) and in 8 of 70 healthy controls (11.4%). Among the eight distinctive epitopes with significant homology between S. sanguinis GroEL and human hnRNP A2/B1, the serum IgA reactivity of BD patients was markedly higher with epitope 3 (hnRNP A2/B1 peptide 33-46 and GroEL peptide 57-70) and epitope 6 (hnRNP A2/B1 peptide 177-188 and GroEL peptide 347-358). Conclusion:? We identified a S. sanguinis GroEL protein as a target of serum anti-S. sanguinis IgA antibody reactivity in BD patients. In addition, BD patients exhibited serum IgA reactivity against homologous epitope regions between S. sanguinis GroEL and human hnRNP A2/B1. PMID:23137016
Abstract in english Group B Streptococcus (GBS) is the main etiological agent of neonatal sepsis in developed countries, however there is no detailed information on its incidence in Brazil. We registered the incidence and lethality of GBS infection in a Brazilian private maternity hospital from April 1991 to March 2000. Maternal risk factors contributing to neonatal infections were also scored. The rate of infection was determined by checking for GBS in the blood and liquor of symptomatic ne (more) onates within 72 hours of birth. Sepsis and/or early onset meningitis were diagnosed in 43 neonates (32 cases in blood, 1in liquor and 10 in blood and liquor). The overall incidence was 0.39 per thousand neonates and remained quite constant throughout the period, ranging from 0.25-0.63. Septic shock occurred in 33 neonates within 1 to 36 hours of birth (mean 15 hours). Among those patients, 26 (60%) died between the 5th and the 85th hour after birth. Maternal risk factors, according to CDC criteria, included: gestational age below 37 weeks in 26 cases (60%), amniorrhexis equal or superior to 18 hours in 7 cases (16%), and maternal temperature equal or superior to 38ºC in 4 cases (9%). None of the mothers had received prophylactic antibiotics during labor nor were urine, rectal or vaginal swabs screened for GBS. Although the incidence of GBS infection in the population in this study was lower than that found in developed countries, its rate of mortality was higher. The death rate could be reduced through recognition of the risk factors and prophylactic antibiotics during labor.
Pili have been shown to contribute to the virulence of different Gram-positive pathogenic species. Among other critical steps of bacterial pathogenesis, these structures participate in adherence to host cells, colonization and systemic virulence. Recently, the presence of at least four discrete gene clusters encoding putative pili has been revealed in the major swine pathogen and emerging zoonotic agent Streptococcus suis. However, pili production by this species has not yet been demonstrated. In this study, we investigated the functionality of one of these pili clusters, known as the srtF pilus cluster, by the construction of mutant strains for each of the four genes of the cluster as well as by the generation of antibodies against the putative pilin subunits. Results revealed that the S. suis serotype 2 strain P1/7, as well as several other highly virulent invasive S. suis serotype 2 isolates express pili from this cluster. However, in most cases tested, and as a result of nonsense mutations at the 5' end of the gene encoding the minor pilin subunit (a putative adhesin), pili were formed by the major pilin subunit only. We then evaluated the role these pili play in S. suis virulence. Abolishment of the expression of srtF cluster-encoded pili did not result in impaired interactions of S. suis with porcine brain microvascular endothelial cells. Furthermore, non-piliated mutants were as virulent as the wild type strain when evaluated in a murine model of S. suis sepsis. Our results show that srtF cluster-encoded, S. suis pili are atypical compared to other Gram-positive pili. In addition, since the highly virulent strains under investigation are unlikely to produce other pili, our results suggest that pili might be dispensable for critical steps of the S. suis pathogenesis of infection. PMID:20052283
Structural insights into catalysis by ?C-S lyase from Streptococcus anginosus.
Hydrogen sulfide (H(2)S) is a causative agent of oral malodor and may play an important role in the pathogenicity of oral bacteria such as Streptococcus anginosus. In this microorganism, H(2)S production is associated with ?C-S lyase (Lcd) encoded by lcd gene, which is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that catalyzes the ?,?-elimination of sulfur-containing amino acids. When Lcd acts on L-cysteine, H(2)S is produced along with pyruvate and ammonia. To understand the H(2)S-producing mechanism of Lcd in detail, we determined the crystal structures of substrate-free Lcd (internal aldimine form) and two reaction intermediate complexes (external aldimine and ?-aminoacrylate forms). The formation of intermediates induced little changes in the overall structure of the enzyme and in the active site residues, with the exception of Lys234, a PLP-binding residue. Structural and mutational analyses highlighted the importance of the active site residues Tyr60, Tyr119, and Arg365. In particular, Tyr119 forms a hydrogen bond with the side chain oxygen atom of L-serine, a substrate analog, in the external aldimine form suggesting its role in the recognition of the sulfur atom of the true substrate (L-cysteine). Tyr119 also plays a role in fixing the PLP cofactor at the proper position during catalysis through binding with its side chain. Finally, we partly modified the catalytic mechanism known for cystalysin, a ?C-S lyase from Treponema denticola, and proposed an improved mechanism, which seems to be common to the ?C-S lyases from oral bacteria. PMID:22674431
In 2002 an increased number of cochlear implant related meningitis cases was reported by the U. S. Food and Drug Administration (FDA). The most commonly identified causative agent was Streptococcus pneumoniae. Although most cases of meningitis were related to a special electrode design, the risk for post-operative pneumococcal meningitis might nonetheless be enhanced by opening of the cochlea during implantation. In the present study, a threshold model for middle ear inoculation of S. pneumoniae was established in the guinea pig after cochlear implantation to assess the post-operative risk of meningitis. Guinea pigs were implanted unilaterally with a silicone cochlear implant electrode dummy. Five weeks after implantation, animals were challenged via the middle ear with a clinically relevant strain of S. pneumoniae and monitored over a period of five days for signs of meningitis. Meningitis was confirmed by clinical outcome in the animals, histological investigation of brains, as well as by pleocytosis and presence of bacteria in cerebrospinal fluid (CSF). By inoculation of varying numbers of bacteria (between 1 × 10(4) and 1 × 10(9) CFU/ml in 10 ?l), a threshold model was established. The attack rate, pattern and onset of meningitis depended on number of inoculated bacteria. An increased meningitis rate in different experimental groups shows that greater bacterial burden leads to an increased attack rate after intratympanal inoculation. The established animal model provides a potential tool to assess the meningitis risk after cochlear implantation. Its implementation in future studies will allow the investigation of existing and newly developed prostheses for postoperatively infection risk. PMID:22575208
Genotypic profiles by AP-PCR of streptococcus mutans in caries-active and caries-free preschoolers.
Streptococcus mutans, an acidogenic and aciduric microorganism that colonizes the oral cavity is recognized as the main causal agent of dental caries. Epidemiological studies have shown a strong correlation between the number of S. mutans in the oral cavity and prevalence and incidence of caries. At present, different genotypic and phenotypic methods are known to determine the profiles of settling and epidemiological distribution of S. mutans. The aim of this study was to investigate the profiles of S. mutans isolated from children with and without dental caries by using the AP-PCR (arbitrarily primed polymerase chain reaction) and api-Zym methods. In the AP-PCR method, random DNA segments of the target bacterium are amplified with single primers of arbitrary sequence. The api-Zym system (bioMirieux, Marcy-létoile, France) is a phenotypic micro-method that allows simultaneous detection of 19 enzymatic activities from bacterial inoculum. A transversal observational study was conducted, which finally included 1203- to 5-year-old children (75 with and 45 without dental caries), who attended a preschool institution in Bogota (Colombia). S. mutans was isolated from 15 of the 45 children without dental caries (33.3%) and from 31 of the 75 children with caries (41.33%). In the 46 children, 69 S. mutans isolates were identified: 24 isolates in the 15 children without dental caries and 45 isolates in 31 children with dental caries. With api-Zym system, 36 different phenotypes were detected: 22 in the caries group and 15 in the caries-free group. The phenotype XX was present in both groups. With the AP-PCR method, 27 different fingerprinting profiles were identified: 22 for the caries group and 9 of the healthy group; the two groups of patients shared four of these genomic profiles. In conclusion, the information shows a great diversity in S. mutans genotypes and phenotypes in the population studied. PMID:21053688
OBJECTIVE To describe pathogens identified through routine clinical practice and factors associated with identifying Shiga toxin-producing Escherichia coli (STEC) infection in patients with postdiarrheal hemolytic uremic syndrome (D+HUS). DESIGN Population-based active surveillance. SETTING Hospitals in the FoodNet surveillance areas from 2000 through 2010. PARTICIPANTS Children younger than 18 years with D+HUS. MAIN EXPOSURES Testing for STEC and demographic and clinical characteristics. MAIN OUTCOME MEASURES Percentage of patients with evidence of infection with likely HUS-causing agents and associations between exposures and evidence of STEC infection. RESULTS Of 617 patients, 436 (70.7%) had evidence of infection with likely HUS-causing agents: STEC O157 (401 patients), non-O157 STEC (21 patients), O157 and non-O157 STEC (1 patient), Streptococcus pneumoniae (11 patients), and other pathogens (2 patients). Among patients without microbiological evidence of STEC, 76.9% of those tested had serologic evidence of STEC infection. Children more likely to have evidence of STEC infections included those patients tested for STEC less than 4 days after diarrhea onset, 12 months or older (71.6% vs 27.8% if <12 months of age), with infections as part of an outbreak (94.3% vs 67.3%), with bloody diarrhea (77.2% vs 40.4%), with onset during June through September (76.9% vs 60.1%), with a leukocyte count greater than 18 000/?L (to convert to ×109/L, multiply by 0.001) (75.7% vs 65.3%), or with only moderate anemia (hemoglobin >7.0 g/dL [to convert to grams per liter, multiply by 10] or hematocrit greater than 20% [to convert to a proportion of 1, multiply by 0.01]) (75.1% vs 66.3%). However, many of these associations were weaker among children with thorough STEC testing. CONCLUSIONS Early stool collection for E coli O157 culture and Shiga toxin testing of all children with possible bacterial enteric infection will increase detection of STEC strains causing HUS. In the absence of microbiological evidence of STEC, serologic testing should be performed. PMID:22869280
Dalbavancin is a bactericidal dimethylaminopropyl amide glycopeptide derivative possessing an extended serum elimination half-life in humans that allows once-weekly dosing for the therapy of Gram-positive infections. Strains from this baseline surveillance protocol in North America (NA; USA and Canada) and Europe (EU, 14 countries) were sampled in 2003. A total of 7,765 Gram-positive isolates (3,695 from NA and 4,070 from EU) were tested by reference broth microdilution methods against dalbavancin and 10 comparator agents. Species were analyzed separately by resistance phenotypes such as methicillin- (oxacillin-) resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and penicillin-resistant Streptococcus pneumoniae. Dalbavancin and other glycopeptides were very active against staphylococci (n=4648) with dalbavancin being 16- to 32-fold more potent than vancomycin (MIC90, 0.06 versus 2 mg/L). MRSA rates were greater (31.6%) in NA than in EU (26.1%). Quinupristin/dalfopristin resistance (MIC, > or = 2 mg/L; 0.1-0.5%) was documented more often in EU compared to NA. Dalbavancin (MIC50, 0.03-0.06 mg/L) was active against enterococci, except VanA resistance phenotypes. VRE rates were lower in EU (8.3%) then in NA (35.9%) from this resistance-enhanced enterococcal collection. Streptococci (dalbavancin MIC90, 0.016-0.03 mg/L) were generally most susceptible to glycopeptides (100.0%), quinupristin/dalfopristin (98.6-100.0%) and linezolid (100.0%); but dalbavancin was 16-fold more active than comparators. All vancomycin-susceptible enterococci and > 90% of vanB VRE had dalbavancin MIC values at 8 mg/L (median MIC, > or = 8 mg/L). Dalbavancin MIC values were not adversely influenced by geographic region or resistance phenotype (except vanA VRE). Infrequently isolated Gram-positive organisms such as Bacillus spp. (MIC90, 0.12 mg/L), Corynebacterium spp. (MIC90, 0.12 mg/L), Listeria monocytogenes (MIC90, 0.25 mg/L) and Micrococcus spp. (MIC90, 0.03 mg/L) were very susceptible to dalbavancin. In conclusion, these 2003 baseline resistance surveillance findings confirm the potent dalbavancin activity compared to several comparator agents against important Gram-positive pathogens. This high volume international survey indicates potential therapeutic roles for dalbavancin against many troublesome resistant Gram-positive phenotypes. PMID:16433188
Multiple antibiotic resistance of clinically important bacteria are of major concern worldwide. Alterations of drug targets or enzymatic inactivation of antimicrobial agents are the well known mechanisms of antimicrobial drug resistance. Besides these well known mechanisms, recent studies have shown that a further resistance mechanism, active drug efflux, has become increasingly important in the current threat of multidrug resistance. It involves certain bacterial transport proteins which pump out toxic antimicrobial compounds from the cell. Drug efflux pump proteins in bacteria fall into five distinct protein super families [ATP binding cassette super family (ABC), Major facilitator super family (MFS), Small multidrug resistance super family (SMR), Multidrug and toxic compound extrusion (MATE) super family, Resistance-nodulation-cell division (RND) super family] and are mostly encoded by chromosomal genes. Among them, the members of RND protein super family are widely distrubuted in Gram negative bacteria and play siginificant role in both, intrinsic and acquired multidrug resistance of these bacteria with very wide substrate specificity. RND type multidrug efflux proteins usually function together with an outer membrane canal protein (OMP) and a membrane fusion protein (MFP) to pump out drugs. AcrAB-TolC of Escherichia coli and MexAB-OprM of Pseudomonas aeruginosa are the typical examples of these tripartite systems. They are constitutively expressed in wild type cells and play significant role in intrinsic resistance of these bacteria. However, multidrug resistance which is of major clinical significance, rises as a result of overexpression of these pump systems due to mutations and elevated levels of resistance are recorded to structurally unrelated antimicrobial drugs such as fluoroquinolones, beta-lactams, tetracyclines, chloramphenicol, trimethoprim, aminoglycosides and toxic compunds. Synthesis of RND type pump proteins are regulated by complex genetic mechanisms and global activator proteins (MarA, SoxS, Rob) are significant in the induction of overexpression of these efflux pump systems. Outer membrane of Gram negative bacteria with its unique lipopolysaccharide rich structure also contributes to drug efflux and other antimicrobial resistance mechanisms by reducing the influx rate of toxic antimicrobial compunds. Multidrug efflux pump proteins found in Gram positive bacteria and mycobacteria are usually the members of protein super families other than RND family and their substrate profiles are more limited. However, some of these efflux proteins (NorA, MsrA, QacA in Staphylococcus aureus; PmrA and EmeA in Streptococcus pneumoniae) have clinical significance in the resistance to several antimicrobial agents (fluoroquinolones, macrolids) and toxic substances (quarternery ammonium compounds). In this review article, the role of cell wall organization and active efflux pump systems in multidrug resistance of bacteria have been discussed. PMID:17682720
Abstract in spanish La quimioterapia antimicrobiana en medicina humana y veterinaria es la principal herramienta terapéutica frente a los microorganismos patógenos causantes de enfermedades infecciosas; sin embargo, con el transcurrir de los años se ha observado la aparición de cepas multiresistentes. Dentro de las medidas utilizadas a nivel mundial para enfrentar este riesgo, están el uso de antimicrobianos bajo receta veterinaria, la rotación en el uso de estos fármacos y la instaur (more) ación de programas permanentes de monitoreo de la resistencia bacteriana. Este trabajo forma parte de un proyecto de fármacovigilancia de resistencia bacteriana en el ganado lechero, cuyo objetivo fue determinar la sensibilidad en bacterias patógenas aisladas de mastitis en vacas lecheras de la V Región, Región Metropolitana (VR,RM) y X Región (XR), frente a los antimicrobianos utilizados con mayor frecuencia en lecherías del país. Para evaluar la resistencia bacteriana, se utilizó el Método de Dilución en Placa con el fin de determinar la Concentración Mínima Inhibitoria (MIC) de cada cepa bacteriana. En la VR,RM a partir de 963 muestras de leche, se lograron aislar 449 cepas bacterianas, observándose un fuerte predominio de E. coli (40.76%). En la XR, de 2.000 muestras se aislaron 1.012 cepas, observándose un claro predominio de S. aureus (55.53%). Las bacterias grampositivas (Staphylococcus aureus, Streptococcus spp y Staphylococcus coagulasa negativo) presentaron altos porcentajes de resistencia ( 25%), frente a amoxicilina, ampicilina, penicilina, estreptomicina y lincomicina. Para S. aureus, un 6.15% y 3.74% de las cepas aisladas de la VR,RM y XR respectivamente, mostraron resistencia a cloxacilina. Las cepas de E. coli presentaron una mayor sensibilidad, no observándose resistencias superiores al 25%. De los resultados se puede concluir también que las bacterias causantes de mastitis en las regiones en estudio presentan resistencia a más de un antimicrobiano, siendo recomendable que la adquisición de estos fármacos se realice a través de receta veterinaria, instaurando además programas permanentes de monitoreo de resistencia bacteriana en nuestro país Abstract in english Antimicrobial chemotherapy in human and veterinary medicine is one of the most important therapeutic tool against pathogenic agents causing infectious diseases; nevertheless, the development of multiple resistant strains during the last years has been reported. Some of the measures adopted to control this problem have been the veterinary prescription of antimicrobials for animal use, the permanent rotation of drugs, and the implementation of continuous monitoring programs (more) for bacterial resistance. In the present paper the sensitivity of pathogenic bacteria isolated from dairy cows suffering mastitis in different regions of Chile against antimicrobials most frequently used in dairy herds is reported. The Plate Dilution Method and the Minimum Inhibitory Concentration (MIC) were used to evaluate the bacterial resistance of each isolated strain. A total of 449 bacterial strains were isolated from 963 aseptically collected milk samples in the 5th and Metropolitan Regions of Chile, E. coli being the most frequent mastitis pathogen recovered. In the 10th Region, however, S. aureus was the main pathogen among 1012 bacterial strains isolated from 2000 milk samples. S. aureus, Streptococcus spp and coagulase-negative Staphilococcus (CNS) were shown to be highly resistant to amoxicilin, ampicillin, penicillin, streptomycin and lincomicyn. Resistance to cloxacilin of S. aureus strains isolated in the 5th-Metropolitan and 10th Regions were 6.2% and 3.7% respectively. On the other hand, a high rate of sensitivity was observed in E. coli with resistance values below 25%. According to these results it is possible to conclude that the mastitis pathogens present in the geographical regions under study are resistant to more than one antimicrobial drug and, therefore, usage of these drugs under medical prescription and implementation of permanent monitoring programs for bacterial resistance are strongly recommended
Abstract in portuguese A produção de leite no sistema orgânico tem despertado o interesse dos produtores rurais, pelo aumento de consumo de produtos naturais. Estudaram-se os aspectos citológicos e microbiológicos do leite no sistema orgânico de produção em quatro propriedades no município de Botucatu, SP, utilizando métodos como CMT, exame microbiológico das amostras positivas, contagem de células somáticas (CCS/mL de leite) e Contagem de Unidades Formadoras de Colônias (UFC de m (more) icrorganismos mesófilos/mL de leite) em amostras individuais de leite em animais com pelo menos um teto positivo ao CMT. Foi também realizado a CCS/mL de leite e UFC/mL de leite, e exame microbiológico de amostras de leite do conjunto (tanque) de cada propriedade. Das 150 glândulas mamárias examinadas, 66 (44,00%) amostras foram positivas ao CMT, com isolamento de Corynebacterium bovis em 37,90%, Staphylococcus aureus (18,20%), S. epidermidis (15,20%), Streptococcus uberis (3,00%) e S. dysgalactiae (3,00%), e isolamento de mais de um agente bacteriano em 7,60% das amostras. Os valores de CCS/mL das amostras do leite de conjunto estiveram dentro dos limites de normalidade em três das quatro propriedades ( Abstract in english Nowadays, farmers have great interest in milk production within an organic system due to the consumers' claim for natural products. The purpose of this paper was to study the cytological and microbiological quality of milk produced by four farms in the county of Botucatu, SP, which use organic system management. A total of 150 mammary gland milk samples were tested by CMT and Somatic Cell Count (SCC/mL milk), microbiological examination, and Colony Former Unit Count (CFU (more) mesophile microrganisms/mL milk). From these individual milk samples, 66 (44.0%) were CMT positive. Corynebacterium bovis was isolated from 37.9% milk samples, Staphylococcus aureus from 18.2%, S. epidermidis from 15.2%, Streptococcus uberis from 3.0%, and S. dysgalactiae from 3.0%. Association of at least two different bacteria species was observed in 7.6% samples. In respect to the whole milk of each farm, the SCC/mL values were in normal limits on three of them (i.e. lower than 400x10³), and considering the CFU/mL, on three farms high levels were observed (8,5x10(5); 1,5x10(6); 4,1x10(5)). From the individual milk samples, contagious mastitis pathogens were isolated predominantly, but environmental microorganisms were detected from the whole milk, as Escherichia coli and Pseudomonas aeruginosa, probably due to contamination during and/or after milking. The results suggest that more than mastitis problems, the four farms studied have hygienic deficiencies, what strengthens the importance of sanitary education to achieve a better milk hygiene quality.
Abstract in portuguese Novos tratamentos são propostos para evitar a progressão da periodontite, sendo a terapia fotodinâmica (PDT) uma notória promessa. Sua aplicação associa o Azul de orto-toluidina a 0,01% (TBO) e uma fonte luminosa a laser de diodo (TwinFlex, Mmoptics), liberando assim, toxinas às bactérias. O objetivo do estudo é avaliar in vitro a eficiência da PDT sobre Aggregatibacter actinomycetemcomitans (A.a.) e Streptococcus sanguinis (S.s.). Preparou-se suspensões distin (more) tas de 2 mL contendo A.a. e S.s. na concentração de 1,5x108 UFC/mL, e divisão de cada suspensão em 3 grupos: Controle (sem tratamento); Corante (suspensão e TBO por 5min) e Corante/Laser (suspensão, TBO por 5 min e laser por 3 min). Promoveu-se a diluição, a semeadura em 20 mL de TSA (A.a.) e de Ágar Brucella (S.s.), em placas de Petri (Método Pourplate), e a incubação da A.a. em microaerofilia e da S.s. em aerobiose, por 48 h a 35oC, para posterior contagem visual das UFC. Os grupos Controle mostraram ótimo crescimento bacteriano (1,5 x 108 UFC/mL). Os grupos Corante não apresentaram redução significativa para ambas bactérias. Os grupos Laser apresentaram redução em relação ao controle, 61,53% para A.a. e 84,32% para S.s. A análise estatística (ANOVA, p Abstract in english New periodontal disease treatments are needed to prevent infection progression. Photodynamic therapy (PDT) is one of the greatest pledges for this purpose. It involves the use of light of specific wavelength to activate a nontoxic photosensitizing agent in the presence of oxygen for eradication of target cells, and can be used for photokilling of microorganisms. This study evaluated in vitro the photodynamic effect of 0.01% toluidine blue-O (TBO) in combination with an Al (more) GaInP diode laser light source on Aggregatibacter actinomycetemcomitans (A.a.) and Streptococcus sanguinis (S.s.). Suspensions (2 mL) containing A.a. and S.s. at 1.5 x 108 CFU/mL concentration were prepared and divided into 3 groups: Control group (no treatment), Dye group (inoculum and TBO for 5 min) and Dye/Laser group (inoculum, TBO for 5 min and laser for 3 min). Next, a dilution for subsequent subculture in 20 mL of Trypic Soy Agar (A.a) and Brucella Agar (S.s.) in Petri dishes (Pourplate Method) was done. Incubation of A.a. in microaerophilia and S.s. in aerobiosis at 35oC for 48 h was performed for subsequent visual counting of CFU/mL. Data were analyzed by one-way ANOVA and Tukey’s HSD test at 5% significance level. For both strains, the control group showed a significantly higher (p
Abstract in portuguese OBJETIVOS: verificar a ocorrência de colonização por Streptococcus agalactiae em gestantes e avaliar a suscetibilidade das amostras isoladas aos antimicrobianos. MÉTODOS: foram avaliadas 167 grávidas entre a 32ª e a 41ª semana de gestação, independente da presença ou não de fatores de risco, atendidas no ambulatório de pré-natal entre fevereiro de 2003 e fevereiro de 2004. O material vaginal/anal, colhido com um único swab, foi inoculado em caldo Todd-Hewitt (more) acrescido de ácido nalidíxico (15 µg/mL) e gentamicina (8 µg/mL), com posterior subcultura no meio de ágar sangue. A identificação foi feita por meio da avaliação da morfologia e tipo de hemólise das colônias no meio de ágar sangue, teste da catalase, teste de cAMP e testes sorológicos. A avaliação da suscetibilidade aos antimicrobianos foi realizada pelos testes de difusão e de diluição em ágar. A análise estatística foi realizada por meio do teste de chi2; valores de p0,05). Todas as 32 amostras isoladas foram sensíveis a penicilina, cefotaxima, ofloxacina, cloranfenicol, vancomicina e meropenem. A resistência a eritromicina e clindamicina foi detectada em 9,4 e 6,2% das amostras, respectivamente. CONCLUSÕES: a incidência relativamente elevada (19,2%) de colonização por S. agalactiae entre as gestantes avaliadas e o isolamento de amostras resistentes, especialmente aos antimicrobianos recomendados nos casos de alergia à penicilina, enfatizam a importância de detectar esta colonização no final da gravidez, associada à avaliação da suscetibilidade aos antimicrobianos, para uma prevenção eficaz da infecção neonatal. Abstract in english PURPOSE: to verify the occurrence of colonization by Streptococcus agalactiae in pregnant women attended at the prenatal outpatient clinic of the Teaching Maternity Hospital of Rio de Janeiro University (UFRJ) and to evaluate the susceptibility of the isolates to antimicrobial agents. METHODS: a total of 167 pregnant women between the 32nd and 41st week of gestation, regardless of risk factors, attended at the antenatal clinic between February 2003 and February 2004, were (more) evaluated. The vaginal/anal material, collected by the same swab, was inoculated in Todd-Hewitt broth to which nalidixic acid (15 µg/mL) and gentamicin (8 µg/mL) were added, with following subcultures onto sheep blood-agar. Identification was carried out observing colony morphology and beta-hemolysis type on blood-agar, catalase, cAMP, and serological tests. The antimicrobial susceptibility testing used agar diffusion and agar dilution methods. Statistical analysis was performed by the chi2 test with the level of significance set at p0.05). All 32 isolated strains were susceptible to penicillin, cefotaxime, ofloxacin, chloramphenicol, vancomycin and meropenem. Resistance to erythromycin and clindamycin was detected in 9.4 and 6.2% of the isolates, respectively. CONCLUSIONS: the relatively high incidence (19.2%) of colonization by S. agalactiae among the evaluated pregnant women and the recovery of antimicrobial resistant strains, especially those recommended in cases of penicillin allergy, emphasize the importance, for a correct prevention of neonatal infections, of detecting colonization at the end of pregnancy and evaluating antimicrobial susceptibility.
Postmarketing surveillance of levofloxacin (LVFX) has been conducted continuously since 1992. The present survey was performed to investigate in vitro susceptibility of recent clinical isolates in Japan to 30 selected antibacterial agents, focusing on fluoroquinolones (FQs). The common respiratory pathogens Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae continue to show a high susceptibility to FQs. In contrast, widely-prevailing resistance to macrolides was markedly noted among S pneumoniae and S. pyogenes. Regarding H. influenzae, the prevalence of beta-lactamase-negative ampicillin-resistant isolates has been increasing year by year (25.8% in 2002, 40.0% in 2004, 50.1% in 2007, and 57.9% in 2010). Enterobacteriaceae showed high susceptibility to FQs, however, prevalence of LVFX-resistant Escherichia coli, including intermediate resistance, was 29.3%, showing an increase over time. Nevertheless, the increase in the prevalence of LVFX-resistant E. coli isolates has slowed since 2007 (8.2% in 2000, 11.8% in 2002, 18.8% in 2004, 26.2% in 2007, and 29.3% in 2010), suggesting the influence of LVFX 500 mg tablets since its approval in 2009. Another Enterobacteriaceae member, Klebsiella pneumoniae, showed low resistance to FQs, in contrast with E. coli. In methicillin-resistant Staphylococcus aureus (MRSA), the percentage of FQ-susceptible isolates was low, at 51.6% for susceptibility to sitafloxacin, and at only around 10% for susceptibility to other FQs. However, methicillin-susceptible S. aureus (MSSA) isolates were highly susceptible to FQs, with the percentage ranging from 88.5% to 99.1%. The prevalence of FQs-resistant isolates in methicillin-resistant coagulase-negative staphylococci was higher than that in methicillin-susceptible coagulase-negative staphylococci, although it was lower than the prevalence of FQ-resistance in MRSA. The prevalence of FQs-resistant Pseudomonas aeruginosa isolates derived from urinary tract infections (UTIs) was 15.4-21.3%, higher than the prevalence of 6.1-12.3% in P. aeruginosa isolates from respiratory tract infections (RTIs). While this trend was consistent with the results of previous surveillance, gradual decreases were noted in the prevalence of FQ-resistant P. aeruginosa isolates derived from UTIs. The prevalence of multidrug-resistant P. aeruginosa was 2.3% among isolates derived from UTIs and 0.3% among isolates from RTIs, a decrease from the results of 2007. Acinetobacter spp. showed high susceptibility to FQs. Imipenem-resistant Acinetobacter baumannii, which is currently an emerging issue, was detected at a prevalence of 2.4% (13 isolates). Neisseria gonorrhoeae showed a high resistance of 81.3-82.5%, to FQs. Ceftriaxone (CTRX) continued to show 100% susceptibility until 2007, but the present survey revealed the advent of resistance to CTRX in some clinical isolates. The result of the present survey indicated that although methicillin-resistant staphylococci, Enterococcus faecium, P. aeruginosa from UTIs, N. gonorrhoeae, and E. coli showed resistance of about 20% or more (19.5-89.2%) against the FQs which have been used clinically for over 17 years, the trends observed were similar to the results of previous surveillance. While FQ resistance has been prevailing in E. coli, E. coli still shows more than 70% susceptibility to FQs. The other bacterial species maintained high susceptibility rates of greater than 80%, against FQs. PMID:23173294
Abstract in spanish Las infecciones pulmonares en niños con cáncer son una complicación grave. El lavado broncoalveolar (LBA) es un procedimiento efectivo para llegar a un diagnóstico etiológico. Se analizaron los resultados de LBA realizados entre noviembre de 2005 y octubre de 2008, en niños con cáncer y neutropenia grave e infiltrados pulmonares para conocer su rendimiento, utilidad clínica y seguridad. Se evaluaron 37 LBA en 35 pacientes. En 19/37 casos los infiltrados radiológi (more) cos fueron focales, en 8 se encontró etiología por LBA. En 15/37 casos las imágenes fueron intersticiales encontrándose etiología en 4, resultando un rendimiento microbiológico superior en las lesiones focales. Las muestras del LBA fueron positivas en 32,4% de los episodios (12/37). Se detectaron 16 microorganismos: 8 bacterias, a saber Mycobacterium tuberculosis (n: 2), Pseudomonas aeruginosa (n: 2), Acinetobacter baumannii (n: 1), A. Iwoffii (n: 1), Streptococcus grupo viridans (n: 1) y Mycoplasma pneumoniae (n: 1); 3 virus: metapneumovirus (n: 2) y citomegalovirus (n: 1); 5 hongos: Pneumocystis jiroveci (n: 2), Aspergillus fumigatus (n: 1), Aspergillus niger (n: 1) y Candida albicans (n: 1). Se reportaron cambios en la conducta terapéutica en 6 de 37 pacientes (16,2%) con inicio de nuevas terapias o suspensión de tratamientos empíricos. El LBA tuvo un adecuado rendimiento, sin complicaciones importantes por lo que debe ser considerado precozmente y realizado con un estudio protocolizado. Abstract in english Introduction: Lung infections are a serious complication in children with cancer. Bronchoalveolar lavage (BAL) has been demonstrated to be an effective procedure for achieving etiologic diagnosis. Method: We did a retrospective analysis of BAL data performed between November 2005 and October 2008 in children with cancer, severe neutropenia and lung infiltrates for assessing its performance, clinical utility and safety. Thirty-seven BAL were evaluated in 35 patients. Resul (more) ts: Focal infiltrates were demonstrated in imaging studies associated with 19/37 BAL; in 8 an infectious agent was found. Interstitial pattern was observed in 15/37, in which there were 4 positive studies, proving a higher microbiological performance in BAL associated with focal lesions. BAL yielded significant microbiological findings in 32.4% (12/37). Sixteen microorganisms were identified in the study: bacteria in 8 cases, Mycobacterium tuberculosis (n: 2), Pseudomonas aeruginosa (n: 2), Acinetobacter baumannii (n: 1), A. Iwoffii (n: 1), group viridans Streptococcus (n: 1), Mycoplasma pneumoniae (n: 1); viruses in 3 cases, metapneumovirus (n: 2) cytomegalovirus (n: 1) and fungal infection in 5 cases, Pneumocystis jiroveci (n: 2) Aspergillus fumigatus (n: 1), Aspergillus niger (n: 1), Candida albicans (n: 1). Therapeutic adjustments were done in 6/37 episodes (16.2%). Conclusion: BAL has a significant role in the evaluation of pulmonary infiltrates in pediatric oncological patients, requiring a prompt and safe diagnosis, which is crucial for the survival with minimal morbidity. Our results suggest that BAL by fiberbronchoscopy should be considered as an initial diagnostic tool in these patients.
Abstract in spanish Entre las medidas farmacológicas de posible utilidad para limitar el impacto de las pandemias gripales en la comunidad están los fármacos antivirales (inhibidores de la neuraminidasa) y las vacunas antigripales y antineumocócicas, ya que la gripe predispone a la neumonía bacteriana por Streptococcus pneumoniae. Entre las medidas no farmacológicas destacan la higiene de manos y la higiene respiratoria. La falta de conocimiento de la efectividad de dichas medidas en s (more) ituación de pandemia justifica que en septiembre de 2009, ante la solicitud de proyectos de investigación por parte del Ministerio de Ciencia e Innovación en su Programa de Investigación sobre la gripe (H1N1) 2009 en España, el CIBER de Epidemiología y Salud Pública presentara un proyecto multicéntrico de casos y controles emparejados por edad, hospital y fecha de hospitalización para investigar sobre estos aspectos en 37 hospitales de 7 comunidades autónomas. Por cada caso hospitalizado confirmado de gripe pandémica se seleccionaba 1 caso confirmado ambulatorio y 3 controles (2 hospitalarios y 1 ambulatorio). En los casos y en los controles se recogían variables demográficas, condiciones médicas subyacentes, utilización de antivirales, vacunas recibidas y hábitos de higiene. En los casos hospitalizados se recogieron, además, información relativa al tratamiento antiviral y evolución de la enfermedad. Hasta octubre 2010 se habían reclutado un total de 3.750 pacientes y se está realizando la depuración de los datos y la recuperación de variables. La implicación de las Direcciones Generales de Salud Pública ha sido fundamental para la adecuación del proyecto a la evolución de la pandemia. Abstract in english Potentially useful pharmaceutical measures to limit the impact of pandemic influenza in the community include antiviral drugs (neuraminidase inhibitors) and the influenza and pneumococcal vaccines, as influenza predisposes to bacterial pneumonia caused by Streptococcus pneumoniae. Non-pharmaceutical measures include hand washing and respiratory hygiene. Due to the lack of knowledge of the effectiveness of these measures in a pandemic situation, in September 2009, CIBER de (more) Epidemiología y Salud Pública presented a multicenter case-control study, with controls matched for age, hospital and date of hospitalization, to investigate these aspects in 37 hospitals in 7 Spanish autonomous communities, in response to the call for research projects by the Ministry of Science and Innovation Research Program on Influenza A (H1N1) in Spain. For each confirmed hospitalized case of pandemic influenza, 1 confirmed outpatient case and 3 controls (2 hospitalized and 1 outpatient) were selected. Demographic variables, underlying medical conditions, use of antiviral agents, vaccines received and hygiene habits were collected for all cases and controls. In hospitalized cases, information on antiviral therapy and disease progression was collected. A total of 3750 patients were recruited by October 2010. Data cleansing and the recovery of variables is now underway. The involvement of the Public Health Directorate has been instrumental in adapting the project to the evolution of the pandemic.
Abstract in portuguese JUSTIFICATIVA E OBJETIVOS: O paciente internado em unidade de terapia intensiva (UTI), geralmente apresenta higiene bucal insatisfatória, podendo a região orofaríngea ser colonizada por patógenos envolvidos em pneumonia nosocomial. O objetivo deste estudo foi investigar a presença de patógenos respiratórios na cavidade bucal em pacientes em UTI. MÉTODO: Foram incluídos neste estudo transversal, 30 pacientes residentes no município de Nova Friburgo no estado do R (more) io de Janeiro, com idade entre 18 e 82 anos e média ponderada de 53,53 anos, sendo 17 homens e 13 mulheres, internados na UTI geral, excetuando a unidade coronariana, do Hospital Municipal Raul Sertã, Nova Friburgo, com diagnóstico de pneumonia nosocomial (PN). Foi realizada cultura das amostras do aspirado traqueal para identificar os micro-organismos responsáveis pela PN. Em contrapartida amostras microbiológicas da placa dental supragengival, da língua e do tubo do umidificador, foram analisadas para avaliação da presença do agente etiológico da PN. RESULTADOS: As bactérias mais freqüentemente encontradas no aspirado traqueal dos pacientes foram S. pneumoniae 23,3% (7), P. aeruginosa 20% (6), S. aureus 13,3% (4), Kleibsella pneumoniae 13,3% (4), Candida albicans 6,6% (2), Streptococcus a-hemolítico 6,6% (2), Staphylococcus sp. 6,6% (2), Acinetobacter calcoaceticus - baumanii complex (A. calcoaceticus) em 1 paciente (3,3% do total de pacientes), Eschericia coli (E.coli) 3,3% (1), Enterobacter cloacae (E. cloacae) 3,3% (1). Nesses pacientes, 70% destas bactérias foram encontradas no biofilme dental, 63,33% em amostras da língua, 73,33% nas amostras do tubo do respirador artificial e em 43,33% em todos as áreas simultaneamente. Não foram observadas diferenças significativas nas proporções das amostras dos locais de coleta (p > 0,05). CONCLUSÕES: Os resultados deste estudo sugeriram que a presença de patógenos respiratórios no biofilme bucal de pacientes internados em UTI pode servir de reservatório para micro-organismos associados com pneumonia nosocomial. Abstract in english BACKGROUND AND OBJECTIVES: Hospitalized patients receiving treatment at intensive care units (ICU) usually show poor oral hygiene, and may have the mouth and oropharingeal region colonized by pathogens involved in nosocomial pneumonia. The presence of these pathogens may increase the risk for respiratory diseases. The aim of this study was to investigate the presence of respiratory pathogens in the oral cavity of hospitalized patients at ICU. METHODS: Were included in the (more) study 30 patients from Hospital Raul Sertã, Nova Friburgo, with the diagnostic of nosocomial pneumonia, and tracheal aspirate samples were cultured to identify the causing microorganisms. In addition, microbiological samples from supragingival dental plaque, tongue and respiratory tube were cultured for the presence of a panel of respiratory pathogens. RESULTS: The most frequently found bacteria in the tracheal aspirate were S. Pneumoniae 23.3% (7), P. aeruginosa 20% (6), S. aureus 13.3% (4), K. pneumoniae 13.3% (4), C. albicans 6.6% (2), a-hemolytic streptococcus 6.6% (2), Staphylococcus sp. 6.6% (2), A. calcoaceticus 3.3% (1), E. coli 3.3% (1) and E. cloacae 3.3% (1). 70% (21) of these microorganisms were found in the dental biofilm, 63.33% (19) in tongue samples; 73.33% (22) in the respiratory tube; and 43.33% (13) in all sampling sites simultaneously. No differences in proportions could be observed between the sampling sites (p > 0.05) CONCLUSIONS: The results of this study show that respiratory pathogens associated with nosocomial pneumonia are present in the oral biofilm of hospitalized patients in ICU, which may serve as a reservoir for these microorganisms.
Methodological variations in the isolation of genomic DNA from Streptococcus bacteria
Abstract in portuguese O gênero Streptococcus encontra-se amplamente distribuído na natureza e algumas espécies constituem a microbiota humana da cavidade bucal, como Streptococcus pyogenes, que pode estar associado a importantes doenças humanas, Streptococcus mutans e Streptococcus sobrinus, relacionados à cárie dental. O DNA genômico destas três espécies foi isolado utilizando-se dois métodos, o primeiro utilizando o detergente brometo de cetiltrimetilamônio (CTAB) à 65ºC e outro (more) associando ultra-som a uma mistura de sílica e celite em CTAB. O método que possibilitou a extração do DNA genômico das bactérias Gram positivas, com qualidade, boa reprodutibilidade fácil execução foi aquele que utilizou ultra-som associado à sílica e celite em CTAB. Abstract in english In this work, genomic DNA of Streptococcus pyogenes, S. mutans and S. sobrinus was isolated using two methods: either using the detergent cetyltrimethylammonium bromide (CTAB) at 65ºC; or by applying ultrasound to a mixture of silica and celite in CTAB. The composite method that used ultrasound was the more efficient, allowing the straightforward extraction of genomic DNA from Gram-positive bacteria with good quality and reproducibility.
Antimicrobial resistance and molecular epidemiology of streptococci from bovine mastitis.
Streptococcus agalactiae (Group B Streptococcus, GBS), Streptococcus dysgalactiae subsp. dysgalactiae (Group C Streptococcus, GCS) and Streptococcus uberis are relevant mastitis pathogens, a highly prevalent and costly disease in dairy industry due to antibiotherapy and loss in milk production. The aims of this study were the evaluation of antimicrobial drug resistance patterns, particularly important for streptococcal mastitis control and the identification of strain molecular features. Antimicrobial resistance was assessed by disk diffusion against amoxicillin-clavulanic acid, cefazolin, cefoperazone, pirlimycin-PRL, rifaximin, streptomycin, chloramphenicol, erythromycin-ERY, gentamicin, tetracycline-TET and vancomycin. Genotypic relationships were identified using pulsed-field gel electrophoresis (PFGE), macrolide and/or tetracycline resistance gene profiling, GBS capsular typing, GBS virulence gene profiling and GBS and S. uberis multi locus sequence typing (MLST). The majority of the isolates were susceptible to all drugs except to aminoglycoside, macrolide, lincosamide and tetracycline. Close to half of the TET resistant isolates have tetO and tetK and almost all ERY-PRL resistant isolates have ermB. A high degree of intra-species polymorphism was found for GCS. The GBS belonged to ST-2, -554, -61, -23 lineages and five new molecular serotypes and human GBS insertion sequences in the cpsE gene were found. Also, GBS of serotype V with scpB and lmb seem to be related with GBS isolates of human origin (same ST-2 and similar PFGE). Overall our results suggested that different therapeutic programs may have been implemented in the different farms and that in most cases clones were herd-specific. PMID:22964008
Macedovicin, the second food-grade lantibiotic produced by Streptococcus macedonicus ACA-DC 198
Streptococcus macedonicus ACA-DC 198 was found to produce a second lantibiotic named macedovicin in addition to macedocin. Macedovicin was purified to homogeneity and mass spectrometric analysis identified a peptide of approximately 3.4 kDa. Partial N-terminal sequence analysis and tandem mass spectrometry revealed that macedovicin was identical to bovicin HJ50 and thermophilin 1277 produced by Streptococcus bovis and Streptococcus thermophilus, respectively. Macedovicin inhibits a broad spectrum of lactic acid bacteria, several food spoilage species (e.g. Clostridium spp.) and oral streptococci. We determined the complete biosynthetic gene cluster of macedovicin. Even though the gene clusters of macedovicin, thermophilin 1277 and bovicin HJ50 were almost identical at the nucleotide level,...
The in vitro activity of ceftobiprole was evaluated against 15 011 clinical isolates obtained from patients in Canadian hospitals between 2007 and 2009. All Staphylococcus aureus were susceptible to ceftobiprole (MIC90's for methicillin-susceptible Staphylococcus aureus and methicillin-resistant Staphylococcus aureus of 1 mg/mL and 2 mg/mL, respectively). Ceftobiprole was active against penicillin-susceptible Streptococcus pneumoniae (MIC90, 0.06 mg/mL), penicillin-resistant Streptococcus pneumoniae (MIC90, 0.5 mg/mL), Streptococcus pyogenes (MIC90, 0.06 mg/mL), Staphylococcus epidermidis (MIC90, 1 mg/mL), and Enterococcus faecalis (MIC90, 1 mg/mL). Over 90% of Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, Citrobacter freundii, Proteus mirabilis, and Serratia marcescens ...
To find a novel lytic enzyme against cariogenic Streptococci, strains showing strong lytic activity have been screened from soil using Streptococcus mutans. A strain identified as Bacillus licheniformis secreted two kinds of lytic enzymes, which were purified by methanol precipitation, CM-cellulose chromatography, gel filtration, and hydroxyapatite chromatography. The molecular weights of these two enzymes, L27 and L45, were 27,000 and 45,000, respectively. Optimum pH and temperature of both enzymes for lytic activity were pH 8 and 37°C. L27 and L45 digest the peptide linkage between L-Ala and D-Glu in peptidoglycan of Streptococcus mutans. The lytic activity was highly specific for Streptococcus mutans, suggesting their potential use as a dental care product.
Streptococcus suis type 2 is a swine pathogen responsible for diverse diseases. Although many virulent factors have been identified and studied, relatively little is known about the pathogenic mechanisms of type 2. The aim of the study was to identify and understand the characterization of Inosine 5-monophosphate dehydrogenase (IMPDH). A 957-bp gene, impdh, was identified in the virulent S. suis serotype 2 (SS2), and analysis of the predicted IMPDH sequence revealed IMP dehydrogenase/GMP reductase domain. The gene encoding for the IMPDH of S. suis was cloned and sequenced. The DNA sequence contained an open reading frame encoding for a 318 amino acid polypeptide exhibiting 23% sequence identity with the IMPDH from Streptococcus pyogenes (YP281355) and Streptococcus pneumoniae (ZP00404150)....
Multiplex PCR assay for species identification of bovine mastitis pathogens
Abstract Aim:- To develop and evaluate a multiplex PCR (mPCR) assay for simultaneous detection of 10 bacterial species causing bovine mastitis namely, Staphylococcus aureus, Staphylococcus chromogenes, Staphylococcus epidermidis, Staphylococcus sciuri, Staphylococcus haemolyticus, Staphylococcus simulans, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis and Escherichia coli in milk. Methods and Results:- A two-tube mPCR assay was developed. The accuracy of the mPCR was evaluated using 56 standard reference strains and 705 strains comprising of E.coli (n-=-99), staphylococci (n-=-522) and streptococci (n-=-84). The threshold of detection of the mPCR assay was 10-fg of genomic DNA and <103-CFU-ml-1. A comparative evaluation of mPCR with culture method using 115 milk...
Effect of 2-hydroxyethyl methacrylate on Streptococcus spp. biofilms
Abstract Aims:- The effect of different concentrations of 2-hydroxyethyl methacrylate (HEMA) was evaluated on biofilm formation and preformed biofilm of Streptococcus mitis, Streptococcus mutans and Streptococcus oralis, alone or combined to each other. Methods and Results:- Twofold serial dilution of HEMA ranged from 12 to 075-mmol-l-1 was added to Streptococcal broth cultures and mature biofilms in 96-well-microtitre plates to evaluate bacterial biomass and cell viability. HEMA affected the Streptococcal population in a strain-specific way producing few significant effects. A reduction on biofilm formation and a detachment of preformed biofilm was recorded in Strep.mitis ATCC 6249, whereas in mixed cultures, the monomer expressed a general aggregative effect on mature biofilms. A reducti...
The purpose of this study was to determine if three strains of bacteria could impact the mechanical or surface properties of a dental resin material. Resin material specimens were incubated at 37?C in sterile saline, tryptic soy broth supplemented with sucrose (TSBS), or TSBS inoculated with Streptococcus mutans, Streptococcus gordonii, or Streptococcus sanguis. The specimens were subjected to Fourier transform infrared spectroscopy before and after incubation. The flexural strength test was performed once a week for 6?weeks. Microhardness and scanning electron microscopy (SEM) was performed on specimens at 1 and 6?weeks. Differences in the area under the carbonyl peak were statistically significant for the specimens incubated in the media inoculated with either S. mutans or S. gordonii. T...
Partial purification of the ATP-driven calcium pump of Streptococcus sanguis
ATP-dependent transport of calcium has been observed in several species of streptococci as uptake of /sup 45/Ca/sup 2 +/ into everted membrane vesicles. Membranes from Streptococcus sanguis and Streptococcus faecalis were solubilized with octyl-..beta..-D-glucoside or Triton X-100, and the extracts reconstituted into proteoliposomes containing Escherichia coli or soybean phospholipid. Calcium transport in reconstituted proteoliposomes was insensitive to the ionophores nigericin and valinomycin and was unaffected by the F/sub 0/F/sub 1/ inhibitor N,N'-dicyclohexylcarbodiimide. Uptake was inhibited by ortho-vanadate with a K/sub i/ in the micromolar range. These results demonstrate that the reconstituted transport activities are not the result of ATP-driven proton pumping via the F/sub 0/F/sub 1/ coupled to a calcium/proton antiporter and suggest that existence of a calcium translocating ATPase. Partial purification of the transport activity from Streptococcus sanguis has been achieved using density gradient centrifugation and FPLC.
Objectives: The intensities and specificities of salivary IgA antibody responses to antigens of Streptococcus mutans, the main pathogen of dental caries, may influence colonization by these organisms during the first 1.5 year of life. Thus, the ontogeny of salivary IgA responses to oral colonizers continues to warrant investigation, especially with regard to the influence of birth conditions, e.g. prematurity, on the ability of children to efficiently respond to oral microorganisms. In this study, we characterised the salivary antibody responses to two bacterial species which are prototypes of pioneer and pathogenic microorganisms of the oral cavity (Streptococcus mitis and Streptococcus mutans, respectively) in fullterm (FT) and preterm (PT) newborn children. Methods: Salivas from 123 inf...
Streptococci are one among the major mastitis pathogens which have a considerable impact on cow health, milk quality, and productivity. The aim of the present study was to investigate the occurrence and virulence characteristics of streptococci from bovine milk and to assess the molecular epidemiology and population structure of the Indian isolates using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Out of a total of 209 bovine composite milk samples screened from four herds (A?D), 30 Streptococcus spp. were isolated from 29 milk samples. Among the 30 isolates, species-specific PCR and partial 16S rRNA gene sequence analysis identified 17 Streptococcus agalactiae arising from herd A and 13 Streptococcus uberis comprising of 5, 7, and 1 isolates from herds B...
Cariogenicity of Three Kinds of Mutans Streptococci from Pig Oral Cavity
Three kinds of mutans streptococci ; Streptococcus ferus and two Streptococcus orisuis serovar strains, in the pig oral cavity were identified previously. The ability to form plaque and synthesise insoluble glucan from sucrose was relatively limited in S. ferus and S. orisuis compared with Streptococcus mutans. PCR analysis showed that the two S. orisuis serovar strains possessed a glucosyltransferase (GTase) I gene. S. ferus could not be amplified with GTase B and GTase I primers. Acid production of all test strains was similar and depended on the cell number. In rat caries experiments, S. ferus and the two S. orisuis serovar strains achieved a lower caries score than S. mutans. The total number of bacteria in the rat oral cavity was also lower for these strains than for S. mutans. The S. ferus and two S. orisuis serovar strains from pigs had relatively weak cariogenic potential compared to S. mutans.
Differential mRNA stability is an important mechanism for regulation of virulence factors in Streptococcus pyogenes (group A streptococcus, GAS), a serious and prevalent human pathogen. We have described 2 Classes of mRNA in GAS that are distinguishable by 1) stability in the stationary phase of growth, 2) kinetics of decay in exponential phase, and 3) effect of depletion of RNases J1 and J2 and polynucleotide phosphorylase (PNPase) on decay in exponential phase. We discuss features of the structure of an mRNA that appear to be important for determining the Class to which it belongs and present a model to explain differential mRNA decay. PMID:21037420
Abstract Coaggregation assays were performed to investigate interactions between oral Bifidobacterium adolescentis and other oral bacterial species. Bifidobacterium adolescentis OLB6410 isolated from the saliva of healthy humans did not coaggregate with Actinomyces naeslundii JCM8350, Streptococcus mitis OLS3293, Streptococcus sanguinis JCM5708, Veillonella parvula ATCC17745 or Porphyromonas gingivalis OB7124, but it did coaggregate with Fusobacterium nucleatum JCM8532. Subsequent examination of biofilm formation on saliva-coated hydroxyapatite discs using FISH revealed that B. adolescentis OLB6410 could not directly adhere to the coated discs. It did, however, adhere to biofilms of A. naeslundii, V. parvula, and F. nucleatum, although it did not coaggregate with A. naeslundii nor with V. ...
Paroxysmal Autonomic Instability with Dystonia after Pneumococcal Meningoencephalitis
Streptococcus pneumoniae is a common cause of bacterial meningitis, frequently resulting in severe neurological impairment. A seven-month-old child presenting with Streptococcus pneumoniae meningoencephalitis developed right basal ganglia and hypothalamic infarctions. Daily episodes of agitation, hypertension, tachycardia, diaphoresis, hyperthermia, and decerebrate posturing were observed. The diagnosis of paroxysmal autonomic instability with dystonia was established. The patient responded to clonidine, baclofen, and benzodiazepines. Although this entity has been reported in association with traumatic brain injury, and as a sequel to some nervous system infections, this is the first case, to our knowledge, associated with pneumococcal meningoencephalitis.
Adult zebrafish model of bacterial meningitis in Streptococcus agalactiae infection
Streptococcus agalactiae (Group B Streptococcus, GBS) is the major cause of severe bacterial disease and meningitis in newborns. The zebrafish (Danio rerio) has recently emerged as a valuable and powerful vertebrate model for the study of human streptococcal infections. In the present study we demonstrate that adult zebrafish are susceptible to GBS infection through the intraperitoneal and intramuscular routes of infection. Following intraperitoneal challenge with GBS, zebrafish developed a fulminant infection 24-48h post-injection, with signs of pathogenesis including severe inflammation at the injection site and meningoencephalitis. Quantification of blood and brain bacterial load confirmed that GBS is capable of replicating in the zebrafish bloodstream and penetrating the blood-brain ba...
Occurrence of bacterial pollution indicators in Boulti (Tilapia nilotica Linn. ) fish
A study was made for the occurrence of coliform and streptococcal groups on the skin surface (32 samples), gills (32 samples), intestinal tract (4 samples) and raw fish flesh (4 samples) and raw fish flesh (4 samples) of Boulti fish (Tilapia nilotica Linn.), a fresh water fish caught from Nasser's Lake in Aswan. Streptococcus group was detected in 13 samples taken from fish surface, 12 samples out of 32 swabs from gills. All intestine samples and raw fish flesh were positive for the streptococcus group. Coliform organisms were detected at nearly 43% of skin or gill samples, 100% of intestine and raw fish flesh samples.
Ethnopharmacological relevance: Zuccagnia punctata Cav. (Fabaceae) is a monotypic species distributed in western Argentina and is traditionally used for the treatment of bacterial and fungal infections. The aim of this study was to demonstrated the antibacterial activity of the Zuccagnia punctata standardized extract and the structurally related non-methoxylated flavonoids with similar pattern of substitution and differences in ring C present in this plant species: 7-hydroxyflavanone (HF), 2',4'-dihydroxychalcone (DHC) and 3,7-dihydroxyflavone (DHF), against Streptococcus pneumoniae clinical isolates using in vitro and in vivo models. Materials and Methods: MIC values of natural products were determined by agar macrodilution method. In vivo activities were investigated in a Streptococcus p...
Leukocytoclastic Vasculitis after Pneumococcal pneumonia in an Elderly Adult
Hypersensitivity vasculitis (HSV) has been used to describe several forms of vasculitis of small blood vessels, including Henoch-Schönlein purpura (HSP), mixed cryoglobulinemia, and allergic vasculitis, etc. HSP is a disease occasionally seen in childhood, and is characterized by dermatological and abdominal symptoms. Here, we report a rare case of HSV which showed a clinical course similar to HSP after pneumococcal pneumonia in an elderly adult. Generally, Streptococcus pneumoniae is the most common pathogen in adult community-acquired pneumonia. Therefore, it is critical to recognize HSV as one of the important complications after bacterial infection, especially Streptococcus pneumoniae.
Abstract in english We report a 58-year-old female presenting with fever and vomiting. The initial laboratory examination disclosed two blood cultures that were positive for Streptococcus Pyogenes. An abdominal CAT scan showed a right basal pneumonia. The patient was treated with antimicrobials and discharged with oral cefadroxil for 21 days. One month after discharge she was asymptomatic and with a normal C reactive protein. Pneumonia is an important differential diagnosis in unknown origin (more) bacteremia caused by Streptococcus Pyogenes. It may have a fulminant evolution and may complicate with abscess and empyema.
Anticaries effect of compounds extracted from Galla Chinensis in a multispecies biofilm model
Xie Q, Li J, Zhou X. Anticaries effect of compounds extracted from Galla Chinensisin a multispecies biofilm model.Oral Microbiol Immunol 2008: 23: 459-465. Copyright 2008 The Authors. Journal compilation Copyright 2008 Blackwell Munksgaard. Introduction: Galla Chinensis is a leaf gall known to have some antibacterial effects. Using an in vitro biofilm model of dental plaque, the present study aimed to evaluate the anticaries effects of Galla Chinensis and its chemical fractions. Methods: A four-organism bacterial consortium (Streptococcus sanguis, Streptococcus mutans, Actinomyces naeslundii, Lactobacillus rhamnosus) was grown on hydroxyapatite (HA) discs, bovine enamel blocks, and glass surfaces in a continuous culture system and exposed to repeated solution pulses. Galla Chinensis extrac...
The clinical use of adjuvants in pneumococcal vaccination: Current status and future perspectives
Streptococcus pneumoniae is one most prevalent bacterial infectious organism with a major effect on public health in both industrialized and developing countries. ( 1, 2) Streptococcus pneumoniae mainly causes disease at the extremities of ages, in the very young ( 65 yrs). ( 2-4) Ninety-one different capsular serotypes can cause pneumococcal disease such as pneumonia, sepsis, or meningitis, and pneumococcal infections kill more people than all other vaccine-preventable diseases combined. ( 3, 5, 6) In developing countries, one out of six childhood deaths is attributed to pneumococcal infections. ( 7) Currently licensed vaccines are based on capsular polysaccharides that induce immune protection primarily via opsonophagocytic antibodies.
For the purpose of nationwide surveillance of antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, the Japanese Society of Chemotherapy (JSC) started a survey in 2006. From 2009, JSC continued the survey in collaboration with the Japanese Association for Infectious Diseases and the Japanese Society for Clinical Microbiology. The fourth-year survey was conducted during the period from January and April 2009 by the three societies. A total of 684 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 635 strains (130 Staphylococcus aureus, 127 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 123 Haemophilus influenzae, 70 Moraxella catarrhalis...
Gemifloxacin: a new fluoroquinolone.
Gemifloxacin is a dual targeted fluoroquinolone with potent in vitro activity against Gram-positive, -negative and atypical human pathogens--pathogens considered to be important causes of community-acquired respiratory tract infections. Gemifloxacin demonstrates impressive minimal inhibitory concentrations (MIC 90 ) values against clinical isolates of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Chlamydia pneumoniae and Legionella spp., with MIC 90 values reported to be 0.016-0.06, 16 microg/ml ( Escherichia coli and Providencia stuartii, respectively), with the majority of the genus having MIC 90 drug concentrations < 0.5 microg/ml. The in vitro activity of gemifloxacin against anaerobic organisms is variable. The MIC values for gemifloxacin are not affected by beta-lactamase production nor by penicillin or macrolide resistance in S. pneumoniae. Gemifloxacin is approved by the FDA to be clinically efficacious against multi-drug resistant S. pneumoniae. The pharmacokinetics of gemifloxacin are such that the drug can be administered orally once-daily to yield or achieve sustainable drug concentrations exceeding the MIC values of clinically important organisms. Gemifloxacin has been shown to target both DNA gyrase (preferred target) and topoisomerase IV (secondary target) - enzymes critical for DNA replication and organism survival - against clinical isolates of S. pneumoniae. This dual targeting activity is thought to be important for reducing the likelihood for selecting for quinolone resistance. Gemifloxacin has been investigated and approved for therapy in patients with community-acquired pneumonia (CAP) and acute exacerbations of chronic bronchitis. In one study, more patients receiving gemifloxacin compared to clarithromycin remained free of exacerbations for longer periods of time (p < 0.016) and gemifloxacin had a shorter time to eradication of H. influenzae than did clarithromycin (p < 0.02). From efficacy studies, gemifloxacin was found to have an adverse profile that was comparable with other compounds. The most frequent side effects were diarrhoea, abdominal pain and headache. Gemifloxacin is a welcomed addition to currently available agents for the treatment of community-acquired lower respiratory tract infections. Other potential indications appear to be within the spectrum of this compound. PMID:15155113
Congenital disorders of the function of polymorphonuclear neutrophils.
This review has concentrated on clinical syndromes for which a congenital basis of polymorphonuclear neutrophil dysfunction has been identified. The first clinical syndrome found to be associated with dysfunctional polymorphs was chronic granulomatous disease of childhood. Identification of a cellular defect in oxidative metabolism and microbicidal activity of polymorphonuclear neutrophils from patients with CGD stimulated intense investigation of the function of phagocytes in several clinical entities characterized by increased susceptibility to infection. Other diseases with a probable congenital basis for polymorph dysfunction include Chediak-Higashi syndrome, myeloperoxidase deficiency, severe glucose-6-phosphate dehydrogenase deficiency, and Down's syndrome. Functional defects have also been identified in neutrophils with morphologic abnormalities, such as the Pelger-Huet anomaly and the May-Hegglin anomaly, and in neutrophils without alkaline phosphatase or with a disorder of the glutathione system. The evidence for a relation between these cellular disorders and susceptibility to infection is tentative. Patients with congenital disorders of polymorphonuclear neutrophil microbicidal function frequently suffer prolonged infections in spite of appropriate antimicrobial therapy, and severe lesions recur with discouraging frequency. These lesions are usually soft tissue or bone abscesses, and the etiologic agents are typically staphylococci, gram-negative enteric species, or fungi. The infectious disease problems of patients with phagocytic cell disorders are usually quite distinct from the problems of patients without immunoglobulins or with complement deficiency. Patients with agammaglobulinemia, for example, suffer recurrent septicemia or meningitis due to Streptococcus pneumonia or H. influenzae. Septicemia, especially with the pyogenic bacterial species, is unusual in patients with polymorphoinuclear dysfunction. A major contribution of the currently intense investigation of cells from patients with congenital disorders of phagocyte function has been the greatly increased understanding of the molecular events necessary for the normal function of these cells. The role of the oxidative metabolic burst during phagocytosis has been clearly identified as essential to the microbicidal function of polymorphs and monocytes, and the glutathione system has been identified as essential to the regulation of these oxidative reactions. It is anticipated that these studies may lead to practical methods for "stimulating the phagocytes" in patients with increased susceptibility to infection. PMID:6251530
Ceftaroline is a new broad-spectrum parenteral cephalosporin with antibacterial activity against the prevalent pathogens causing both acute bacterial skin and skin structure infections (ABSSSIs) and community-acquired bacterial pneumonia (CABP). The Assessing Worldwide Antimicrobial Resistance Evaluation Surveillance Program was conducted in the United States between 2008 and 2010 to assess the in vitro activity of ceftaroline and comparator antibacterial agents against ABSSSI and CABP pathogens. A total of 8469 Staphylococcus aureus isolates and 3593 Streptococcus pneumoniae isolates collected from 72 medical centers representing all US Census regions were submitted to a central reference laboratory (JMI Laboratories, North Liberty, IA) for broth microdilution testing by reference methods. The overall prevalence of methicillin resistance among S. aureus isolates was 52.6%, and although ceftaroline showed more potent activity against methicillin-susceptible S. aureus (minimum inhibitory concentration for 50% [MIC(50)] and 90% [MIC(90)] of organisms, both 0.25 µg/mL) than against methicillin-resistant S. aureus (MIC(50) and MIC(90), both 1 µg/mL), it showed good activity against all 8469 S. aureus isolates (MIC(50) and MIC(90), 0.5 and 1 µg/mL, respectively), with 8296 isolates (98.0%) testing susceptible at the US Food and Drug Administration (FDA) break point of ? 1 µg/mL and no isolates having MICs of >2 µg/mL. Against S. pneumoniae, ceftaroline inhibited 98.7% of tested isolates at the FDA susceptible break point of ? 0.25 µg/mL (MIC(50) and MIC(90), 0.015 and 0.12 µg/mL, respectively) and was 16-fold more active than ceftriaxone (MIC(90), 2 µg/mL). The prevalence of multidrug resistance among S. pneumoniae isolates was 30.1% overall and remained stable over each of the 3 monitored years. Ceftaroline demonstrated high activity (MIC(50) and MIC(90), 0.12 and 0.25 µg/mL, respectively) against multidrug-resistant S. pneumoniae, with only 44 of 1001 strains (4.4%) testing nonsusceptible and all 44 nonsusceptible strains having a ceftaroline MIC of only 0.5 µg/mL. Ceftriaxone resistance among S. pneumoniae was 2.1% (10.9% were nonsusceptible), with an intermediate susceptibility rate of 8.8%, resulting in an overall susceptibility rate of only 89.1%. Ceftaroline surveillance in the United States during 2008-2010 documented sustained potency and spectrum against multidrug-resistant S. aureus and multidrug-resistant S. pneumoniae known to cause ABSSSI and CABP. PMID:22903953
Aquaflor??, a 50% feed premix containing the broad spectrum antibacterial agent florfenicol is available globally to control mortality associated with economically significant systemic bacterial diseases of fish. Florfenicol (FFC) is effective in controlling mortality associated with Streptococcus iniae in tilapia Oreochromis sp. when administered in medicated feed at a dose of 15 mg/kg bodyweight (BW)/d for 10 consecutive days. Our objective was to characterize the depletion of the FFC marker residue, florfenicol amine (FFA), from the edible tissue of market-weight Nile tilapia O. niloticus x O. niloticus and hybrid tilapia O. niloticus x O. aureus offered feed medicated with FFC at a nominal dose rate of 15 mg/kg BW/d for 12 days. Near market-weight tilapia were obtained from a commercial tilapia farm, distributed to 2 single pass (one for Nile tilapia and one for hybrid tilapia), flow-through systems and maintained at 27 ??C under a 15 h light:9 h dark photoperiod over a 41-d pre-dosing period. During the dosing period, tilapia were offered feed medicated with FFC at a concentration of 1.479 g/kg at 1% BW daily divided in three equal offerings. The initial 10-d dosing period was extended to 12 d because one tank did not consume > 75% of the feed offered during the first two dosing days. The total dose consumed by fish in each of the 2 tanks ranged from 147 to 167 mg/kg. Once during the pre-dose period and on days 1, 2, 4, 7, 14, 21, and 28 of the post-dose period, groups of fish were indiscriminately removed from each tank, measured for weight and length, scaled, filleted, and the skin-on fillets stored at tilapia fillet after withdrawal from medication and depletion followed first-order kinetics with an estimated half-life of 2.32 d. The FFA tolerance limit, calculated as the 99th percentile of the potential residue level at 95% confidence, had depleted to less than the 1 ??g/g maximum residue level by 6.14 d after the dosing period.
Community-acquired pneumonia (CAP) is still a serious life-threatening disease, in which the etiologic agent cannot be identified in more than 50% of patients despite advanced diagnostic methods. The most commonly used methods in the determination of CAP etiology are culture and serological tests. Since early and accurate therapy reduces the mortality in CAP cases, rapid and reliable diagnostic methods are needed. The aim of this study was to determine the bacterial etiology in adult patients with CAP by implementing multiplex polymerase chain reaction/reverse line blot hybridization (M-PCR/RLBH) assay combined with conventional methods. A total of 128 cases (94 were male; age range: 19-81 years, mean age: 58) who were admitted to our hospital and clinically diagnosed as CAP between November 2008 - November 2010, were included in the study. Respiratory samples (sputum and/or bronchoalveolar lavage) obtained from patients were searched by M-PCR/RLBH method (Gen ID®, Autoimmun Diagnostika GmbH, Germany) in terms of the presence of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella pneumophila nucleic acids. The samples were simultaneously inoculated onto 5% sheep blood agar, chocolate agar, haemophilus isolation agar, buffered charcoal yeast extract-selective agar and EMB agar media for cultivation. Serum samples obtained from the cases were tested for IgM and IgG antibodies against C.pneumoniae by microimmunofluorescence (Focus Diagnostic, USA) and against L.pneumophila and M.pneumoniae by indirect immunofluorescence (Euroimmun, Germany) methods. The bacterial etiology was identified in 59 (46.1%) of 128 patients with CAP and a total of 73 pathogens were detected. The leading organism was S.pneumoniae (n= 32, 25%), followed by H.influenzae and M.pneumoniae (n= 9, 7%), gram-negative bacilli (n= 10, 7.8%), M.catarrhalis (n= 6, 4.7%), C.pneumoniae (n= 4, 3.2%), L.pneumophila (n= 2, 1.6%) and Staphylococcus aureus (n= 1, 1.4%). Infection with atypical pathogens were detected in 15 (11.7%), and mixed infections in 14 (10.9%) patients. The detection rate of microorganisms (S.pneumoniae, H.influenzae, M.catarrhalis, C.pneumoniae, L.pneumophilia, M.pneumoniae) searched by M-PCR/RLBH method was 41.4% (53/128), while those microorganisms were detected in 23.4% (30/128) of the patients by conventional methods, representing a significant difference (p< 0.05). It was concluded that M-PCR/RLBH method supplemented the determination of bacterial etiology in CAP cases by increasing the rate of detection from 23.4% to 41.4%. The results indicated that empirical treatment of CAP should primarily include antibiotics against S.pneumoniae, M.pneumoniae and H.influenzae in our region. PMID:23188566
Objectives: In most countries bacteraemia is a reportable infection only if the causative agent is subject to national surveillance. In a few countries all cases of bacteraemia are reportable but only one episode per microorganism is included per year. Therefore population-based data are sparse especially with regard to the epidemiology of recurrent bacteraemia. We present data from a newly established collaborative network in Denmark with prospective registration of bacteraemia in a population of approximately 1.7 mill. inhabitants. Methods: Three departments of clinical microbiology (DCMs) participate in the network (Hvidovre Hospital and Herlev Hospital, The Capital Region and Aalborg Hospital, North Denmark Region). Bacteraemia is defined as a clinical episode with one or more positive blood cultures (BCs) given significance by a clinical microbiologist and the attending physicians. A recurrence was defined as a positive BC with the same microorganism/s as obtained ?30 days or with another microorganism/s >48 hours after the first positive BC, respectively. We included all patients with bacteraemia during 2006-2007 and follow-up extended for 6 months or until death. Results: In total, recurrent Escherichia coli bacteraemia was the most frequent with 23 to 31 episodes (table). A recurrent episode of either Staphyloccus aureus or Streptococcus pneumoniae bacteraemia was rare in the participating hospitals (2.0% to 3.9% and 0.6% to 1.0%, respectively). For all major blood culture pathogens the frequency range was 0% to 4.1% with the exception of Enterococcus faecalis (range 0% to 9.4%; table). A recurrent episode with any microorganism was most frequent following bacteraemia caused by E. faecalis (range 8.9% to 24.5%) and Klebsiella pneumoniae (range 6.7 to 11.3%). The frequency of recurrent candidaemia ranged from 6.9% to 13.6% (table). Conclusion: The frequency of recurrent S. aureus and S. pneumoniae bacteraemia was lower than reported in previous studies. We found only small differences among major pathogens in the frequency of recurrence with the same microorganism. However, recurrent bacteraemia with any microorganism is common subsequent to K. pneumoniae and E. faecalis bacteraemia and to a lesser extent candidaemia. This suggests that host factors and therapeutic regimens in these patients should be targeted in further studies in order to optimise bacteraemia management.
Abstract in spanish El consumo de moluscos bivalvos ha sido asociado con infecciones microbianas aún en casos donde los mismos cumplen con los parámetros de calidad bacteriológica. El proceso de depuración se realiza con el fin de eliminar, de forma natural, los microorganismos presentes en moluscos bivalvos, los cuales han sido acumulados por su proceso de filtración. En este estudio se determinó la tasa de depuración de indicadores potenciales de contaminación. Se realizaron cuatro (more) experimentos con la almeja Polymesoda solida, la cual poseía niveles altos de índices contaminantes de forma natural. Para evaluar el proceso de depuración se utilizaron como indicadores bacterianos los coliformes totales (CT), coliformes fecales (CF), estreptococos fecales (SF), enterococos (EN) y bacterias aerobias mesófilas (AM). El contenido inorgánico total (CIT) se utilizó como indicador del contenido de arena. La desinfección del agua marina, preparada artificialmente, se realizó irradiando con luz UV durante 48 h. El proceso de depuración se realizó durante 120 horas (5 días) a 28°C y 5 UPS, en tanques de 150 L de capacidad. La tasa de remoción bacteriana y física en Polymesoda solida fue más eficiente (80%) durante las primeras 72 h, alcanzando una calidad bacteriológica y física adecuada para el consumo, sin importar que los ejemplares fueron recolectados de sitios que no cumplían con los niveles aceptables de calidad. Abstract in english ABSTRACT The consumption of shellfish has been associated with microbial infections
