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AVALIACAO DO EFEITO DO VENENO DE APIS MELLIFERA EM CULTURAS DE E. COLI, S. TYPHIMURIUM E Y. ENTEROCOLITICA TRATADAS COM BLEOMICINA

Varanda, Eliana Aparecida
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 155-163
Português
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36.2%
Apis mellifera bee venom (Africanized honey bee) was tested for the ability to protect against the lethal effect of bleomycin, an antibiotic and antineoplastic agent. Since the radioprotective effect of the venom has been observed on the other biological systems, in the present study the venom was applied to cultures of enterobacteria treated with bleomycin, a radiomimetic agent. The venom did not act as a protective agent against bleomycin in E. coli, S. typhimurium or Y. enterocolitica.

Fermentacao de 26-deoxilaidlomicina por Streptomyces sp. Ar386

Ujikawa, K.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 77-80
Português
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36.2%
In a previous work a strain of microorganism was isolated in Araraquara region, SP, Brazil, and characterized as being Streptomyces sp. Ar386, producer of 26-deoxylaidlomycin and of more three polietheric antibiotics. In this paper there are presented studies about fermentation characteristics of the antibiotic performed in incubator agitator utilizing various cultivation technics and media. A medium containing part of energy source as free sugar and part as amilaceous material presented the best result. As the Streptomyces sp. Ar386 produced few spores, it was necessary special care to provide sufficient quantity of microorganisms in inoculation. The biosynthesis of antibiotics intensified between the forth and seventh day. The yields varied from 8 to 443 mg of antibiotic complex per litre of medium. As a polyether antibiotic it may be used as anticoccidal agent in poultry and as growth promoters in cattle and swine.

Antibiotic 26-deoxylaidlomycin isolated from Streptomyces sp. Ar386 from Brazilian soil

Ujikawa, Keidi; Vilegas, Wagner; Vilegas, Janete H. Y.; Llabrés, Gabriel
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 185-191
Português
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46.12%
An actinomycete strain (Ar386) was isolated from the soil of the Araraquara regio, SP, Brazil. The strain, named Streptomyces jacareensis, formed irregular rayed, rugose, grayish-white mycelium with sinuous, branched hyphae carrying rare isolated spores; assimilated glucose, galactose, inositol, ribose, maltose, sucrose, melibiose and starch but not mannitol, rhamnose, arabinose, xylose, lactose and raffinose; and contained LL- diaminopimelic acid in its cell wall. An antibiotic active against Gram- positive bacteria, which was characterized as being 26-deoxylaidlomycin and which may have application against poultry coccidiosis, was isolated from cultures of the strain. This was the first isolation of this antibiotic from a microorganism of the genus Streptomyces and also the first isolation of this antibiotic in Brazil.

Re-evaluation of antibiotic and mercury resistance in Escherichia coli populations isolated in 1978 from Amazonian rubber tree tappers and Indians

Nascimento, Andréa M. A.; Campos, Claudia E. P.; Campos, Evanil P.; Azevedo, João L.; Chartone-Souza, Edmar
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 407-411
Português
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46.07%
A study was carried out to assess the stability of antimicrobial susceptibility of wild isolates upon long-term storage using fifty-three Escherichia coli strains isolated in 1978 from feces of healthy children from the Amazon region in Brazil, exposed to low levels of antimicrobial agents, and examined for resistance to mercury and four antibiotics. All of the strains were kept in Lignieres medium at room temperature and were transferred to fresh media four times during this period. Thirty-five out of the 53 strains analyzed in 1978 were viable. Upon recovery, antibiotic and mercury resistance was estimated. All of the 35 strains maintained their original phenotype in a stable fashion, except for one multiresistant strain which became susceptible to kanamycin. Fifty-four percent of the strains exhibited a resistance phenotype, among which 47% had conjugative plasmids.

Antibiótico antifungico produzido por um estreptomiceto da região de Araraquara

Bachiega, G. L.; Vilegas, Wagner; Ujikawa, Keidi
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 29-37
Português
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With the significant increase in the incidence of invasive fungal infections during the last decade, mainly in patients with cancer, AIDS and other hospitalized patients who stay for long periods in intensive care units, there is an urgent need to screen for new antifungal agents possessing some advantages over known ones. This article reports a search in the field for a microorganism producing antibacterial and antifungal substances. Strains from soil samples collected in the region of Araraquara, Brazil, were isolated and analyzed for their antimicrobial potential against standard microorganisms (fungi Candida albicans and Aspergillus oryzae and bacteria Staphylococcus aureus and Escherichia coli). Out of the 64 strains isolated, 34 produced detectable antimicrobial activity. The streptomycete strain Ar4014 was chosen for further study, owing to its good antimicrobial activity against Candida albicans. Two of the fermentation media tested, 608-K and 602-B, were found to be best for the production and extraction of the antibiotic from Ar4014. After chromatographic separation of the crude extract on a silica column, the active fractions obtained showed UV-VIS absorption peaks characteristic of normal pentaenic antibiotics. The antibiotic was provisionally designated Ara 4014-75.; Com o aumento significativo na incidência de infecções fúngicas invasivas durante a última década...

Importância de Yersinia enterocolitica em microbiologia médica

Falcão, Juliana Pfimer; Falcão, D. P.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 9-19
Português
Relevância na Pesquisa
36.1%
Y. enterocolitica is a human invasive enteropathogen which causes a number of intestinal and extraintestinal clinical symptoms of various degrees of severity, ranging from mild gastroenteritis to mesenteric lymphadenitis, which mimics appendicitis and in rare cases can evolve to septicemia. Infection by Y. enterocolitica can also lead to post-infection immunological sequelae including arthritis, erythema nodosum and glomerulonephritis. Pathogenic Y. enterocolitica strains have traditionally been linked to specific biotypes and serogroups and associated to a variety of phenotypic characteristics related to virulence. Molecular genetics studies have pointed to the importance of the pYV virulence plasmid, which encodes various virulence genes, as well that of specific chromosomal virulence genes, in determining the pathogenesis of this bacterium. Intestinal infections by Y. enterocolitica are mostly self-limiting and usually do not need an antibiotic treatment. The occurrence of this microorganism is not as frequently described in Brazil as it is in other countries, such as Japan, USA and many European countries. This review focuses on the general characteristics, pathogenesis, clinical symptoms, virulence characteristics, treatment and antibiotic susceptibility of Yersinia enterocolitica strains isolated in Brazil and around the world.

American visceral leishmaniasis: Factors associated with lethality in the state of São Paulo, Brazil

Madalosso, Geraldine; Fortaleza, Carlos Magno; Ribeiro, Ana Freitas; Cruz, Lisete Lage; Nogueira, Péricles Alves; Lindoso, José Angelo Lauletta
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
Português
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36.19%
Objectives. To identify factors associated with death in visceral leishmaniasis (VL) cases. Patients and Methodology. We evaluated prognostic factors for death from VL in São Paulo state, Brazil, from 1999 to 2005. A prognostic study nested in a clinical cohort was carried out by data analysis of 376 medical files. A comparison between VL fatal cases and survivors was performed for clinical, laboratory, and biological features. Association between variables and death was assessed by univariate analysis, and the multiple logistic regression model was used to determine adjusted odds ratio for death, controlling confounding factors. Results. Data analysis identified 53 fatal cases out of 376 patients, between 1999 and 2005 in São Paulo state. Lethality was 14.1 (53/376), being higher in patients older than fifty years. The main causes of death were sepsis, bleeding, liver failure, and cardiotoxicity due to treatment. Variables significantly associated with death were severe anemia, bleeding, heart failure, jaundice, diarrhea, fever for more than sixty days, age older than fifty years, and antibiotic use. Conclusion. Educational health measures are needed for the general population and continuing education programs for health professionals working in the affected areas with the purpose of identifying and treating early cases...

Cell surface hydrophobicity and adherence of a strain of group B streptococci during the post-antibiotic effect of penicillin

Araújo,Ângela Maria Mendes; Oliveira,Ivi Cristina Menezes de; Mattos,Marcos Corrêa de; Benchetrit,Leslie C.
Fonte: Instituto de Medicina Tropical Publicador: Instituto de Medicina Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2008 Português
Relevância na Pesquisa
36.1%
The minimum inhibitory concentration and post-antibiotic effects of an antimicrobial agent are parameters to be taken into consideration when determining its dosage schedules. The in vitro post-antibiotic effects on cell surface hydrophobicity and bacterial adherence were examined in one strain of group B streptococci. Exposure of the microorganism for 2 h at 37 °C to 1 x MIC of penicillin induced a PAE of 1.1 h. The cell surface charge of the Streptococcus was altered significantly during the post-antibiotic phase as shown by its ability to bind to xylene: hydrophobicity was decreased. Bacterial adherence to human buccal epithelial cells was also reduced. The results of the present investigation indicate that studies designed to determine therapeutic regimens should evaluate the clinical significance of aspects of bacterial physiology during the post-antibiotic period.

Production of a biocontrol agent for crucifers black rot disease

Luna,C.L.; Mariano,R.L.R.; Souto-Maior,A.M.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2002 Português
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36.11%
Of nine epiphytic isolates of the genus Bacillus, only B. subtilis R14, B. pumilus C116, B. megaterium pv. cerealis RAB7, and B. cereus C210 showed antibiotic activity when tested in vitro against the bacterium Xanthomonas campestris pv. campestris LFR-3. Aiming product a biocontrol agent for black rot in crucifers, the production of B. subtilis R14 was evaluated in a batch bioreactor. Rapid growth was observed in a medium containing molasses and yeast extract as C-source and N-source, respectively. During the exponential growth phase, the specific growth rate was 1.2 h-1. A quick sporulation was also observed in a C/N well-balanced medium. After the sporulation phase, maximum viable spore concentrations around 10(9) CFU/mL were obtained. Preliminary sedimentation tests at different pH values showed better biomass separation efficiencies at low pH values.

Overview of tigecycline and its role in the era of antibiotic resistance

Rossi,Flávia; Andreazzi,Denise
Fonte: Brazilian Society of Infectious Diseases Publicador: Brazilian Society of Infectious Diseases
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2006 Português
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36.17%
The increasing antimicrobial resistance found in the many clinically important species of bacteria that commonly cause serious and life-threatening diseases presents a difficult challenge for clinicians, especially when an appropriate initial therapy must be chosen. New antibiotics are urgently needed to address the formidable issues associated with infections caused by vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae and multidrug-resistant Gram-negative bacteria. The need for new antibiotics that effectively resist antimicrobial mechanisms of resistance has become paramount. Tigecycline is a new antimicrobial agent; it is the first in a new class of antibiotics, the glycylcyclines, with properties conferring the ability to overcome many common resistance mechanisms, thus allowing the use of tigecycline for many serious and life-threatening infections for which the use of other antibiotics is no longer appropriate. Tigecycline is a novel expanded spectrum antibiotic that appears poised to meet the latest bacterial challenges facing clinicians, including the serious and life-threatening infections caused by highly resistant bacteria. Tigecycline...

Amino-Terminated Generation 2 Poly(amidoamine) Dendrimer as a Potential Broad-Spectrum, Nonresistance-Inducing Antibacterial Agent

Xue, Xiaoyan; Chen, Xiaoqing; Mao, Xinggang; Hou, Zheng; Zhou, Ying; Bai, Hui; Meng, Jingru; Da, Fei; Sang, Guojun; Wang, Yukun; Luo, Xiaoxing
Fonte: Springer US Publicador: Springer US
Tipo: Artigo de Revista Científica
Publicado em 08/11/2012 Português
Relevância na Pesquisa
36.23%
The treatment of septicemia caused by antibiotic-resistant bacteria is a great challenge in the clinic. Because traditional antibiotics inevitably induce bacterial resistance, which is responsible for many treatment failures, there is an urgent need to develop novel antibiotic drugs. Amino-terminated Poly(amidoamine) dendrimers (PAMAM-NH2) are reported to have antibacterial activities. However, previous studies focused on high generations of PAMAM-NH2, which have been found to exhibit high toxicities. The present study aimed to clarify whether low generations of PAMAM-NH2 could be used as novel antibacterial agents. We found that generation 2 (G2.0) PAMAM-NH2 showed significant antibacterial effects against antibiotic-sensitive and antibiotic-resistant strains but exhibited little toxicity to human gastric epithelial cells and did not induce antibiotic resistance in bacteria. Scanning and transmission electron microscopy analyses suggested that G2.0 PAMAM-NH2 might inhibit the growth of bacteria by destroying their cell membranes. The administration of G2.0 PAMAM-NH2 dose-dependently improved the animal survival rate of mice infected with extended-spectrum beta lactamase-producing Escherichia coli (ESBL-EC) and of animals infected with a combination of ESBL-EC and methicillin-resistant Staphylococcus aureus. A treatment regimen of 10 mg/kg of G2.0 PAMAM-NH2 starting 12 h before inoculation followed by 10 mg/kg at 0.5 h after inoculation rescued 100% of singly infected mice and 60% of multiply infected mice. The protective effects were associated with the reduction of the bacterial titers in the blood and with the morphological amelioration of infected tissues. These findings demonstrate that the G2.0 PAMAM-NH2 is a potential broad-spectrum and nonresistance-inducing antibiotic agent with relatively low toxicity.

Temperate bacteriophages and the molecular epidemiology of antibiotic resistance in Salmonella enterica.

Tan, Sophia
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2010 Português
Relevância na Pesquisa
36.18%
Foodborne diseases caused by non-typhoidal Salmonella represent an important public health problem worldwide (Zhao et al., 2003). The transmission of Salmonella between animals and humans has been well established in epidemiological studies. In the case of complicated illness caused by Salmonella where antibiotics need to be administered, treatment can be compromised if the infecting organism is resistant to the prescribed antimicrobial agent. This study and earlier studies have shown that many Salmonella carry temperate bacteriophages as lysogens. Many of these bacteriophages are capable of mediating generalised transduction (Schicklmaier and Schmieger, 1995; Schicklmaier et al., 1998; Mmolawa et al., 2002). Schmieger and Schicklmaier (1999) demonstrated that bacteriophages ES18 and PDT17 are capable of transduction of antibiotic resistance genes from DT104. Phage-mediated transduction of antibiotic resistance genes has been largely neglected in the study of genetic transfer of antibiotic resistance in bacteria. This study investigates whether bacteriophages exist in antibiotic resistant Salmonella isolates. Such temperate phages in antibiotic resistant isolates could play a significant role in the transfer of resistance to other species of enteric bacteria...

A randomized and prospective study on the value of antibiotic prophylaxis administration in transurethral resection of the prostate

Rodrigues,Paulo; Hering,Flávio; Meller,Alex; Campagnari,João Carlos; D'Império,Márcio
Fonte: Associação Paulista de Medicina - APM Publicador: Associação Paulista de Medicina - APM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2004 Português
Relevância na Pesquisa
36.15%
CONTEXT: Antibiotic prophylaxis in transurethral resection of the prostate is a regular practice in urology. However, its prophylactic effect can be questioned when the antiseptic surgical technique is used. Nonetheless, urine culture-oriented antibiotic therapy is the gold standard for avoiding improper medication usage and bacterial resistance. OBJECTIVE: To study the efficacy of antibiotic usage in patients with negative urine cultures, who were submitted to transurethral resection of the prostate. TYPE OF STUDY: Prospective open labeled study. SETTING: Tertiary care referral hospital PARTICIPANTS: 124 consecutive patients, who were randomly divided into two groups to receive antibiotic prophylaxis or not. MAIN MEASUREMENTS: Cultures from meatus, urine, irrigation and antiseptic fluid, and prostate tissue chips, were compared and analyzed for bacterial sensitivity to the antibiotic used, according to the surgeon's personal criteria. McLennan's test was used for statistical analysis. RESULTS: No statistically significant difference regarding clinical evolution was found between the groups that received or antibiotics or not. Statistical significance was found regarding the occurrence of positive urine cultures during the postoperative period for those not receiving antibiotics...

Profound lymphopenia and bacteraemia

Hawkins, Carolyn; Collignon, Peter; Adams, D N; Bowden, Francis; Cook, Matthew
Fonte: Blackwell Science Asia Publicador: Blackwell Science Asia
Tipo: Artigo de Revista Científica
Português
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36.11%
Bacteraemia often carries a poor prognosis despite prompt antibiotic therapy and is associated with late morbidity and mortality that is difficult to explain. Here, we describe perisistent B- and T- cell lymphopenia in a cohort of patients with Gram-posit

Antibiotic resistance in Streptococcus pneumoniae isolated from children

Nasrin, Dilruba; Collignon, Peter J; Wilson, Elena Alexandrovna; Pilotto, Louis; Douglas, Robert M
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Português
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46.15%
Objective: To determine the level of antibiotic resistance in pneumoniae (S. pneumoniae) isolated from nasal swabs of healthy children. Method: Cross- sectional community survey. Setting: Survey was undertaken in general practice settings in Canberra during March and April 1998. Subjects: Four hundred and sixty-one children under 3 years of age enrolled in a general practice trial of clinical practice guidelines for antibiotic use. Outcome measures: Resistance to penicillin, erythromycin, co-trimoxazole, tetracycline, chloramphenicol and cefotaxime among the isolates of S. pneumoniae. Results: A total of 461 nasal swabs were collected and S. pneumoniae was isolated from 171 (37.1%). Penicillin resistance was found in 12.3% of these isolates, with high level resistance in 0.6%. Resistance rates were higher for cotrimoxazole (44.4%) and erythromycin (18.1%) than for penicillin. Multidrug resistance was found in 19% of these isolates. There was a significant association between the attendance at a day care centre and carriage of pneumococcus (53% vs 32%, odds ratio (OR) 2.4, 95% confidence interval (CI)1.5-3.7, P < 0.001). Children who attended day care centres and had received antibiotics during the 4 months prior to swab collection were three times more likely to carry an antibiotic-resistant isolate than children who had neither attended a day care centre nor received antibiotics (68% vs 40%...

Ruthenium Complexes of Analogues of the Antitumor Antibiotic Streptonigrin

Anderberg, Pia I; Harding, Margaret; Luck, Ian J; Turner, Peter
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
Português
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36.12%
The complexes Ru(L1-CH3)(CO)3Cl, RuL2(CO)2Cl2, and RuL3(CO)2Cl2 (L1= 6-methoxy-5,8-quinolinedione, L2 = 7-amino-6-methoxy-5,8-quinolinedione, L3 = 6,6′-dimethoxycarbonyl-2,2′-bipyridine) were prepared by reaction of L1-L3 with the tricarbonyldichloror

Assignment of the 13 C and 15 N NMR spectra of the antitumour antibiotic streptonigrin

Harding, Margaret; Anderberg, Pia I; Luck, Ian J
Fonte: John Wiley & Sons Inc Publicador: John Wiley & Sons Inc
Tipo: Artigo de Revista Científica
Português
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46.12%
The assignments of the two pyridyl nitrogens and two amino nitrogens in the antitumour antibiotic streptonigrin, and all carbon resonances, were determined by 15N (HSQC, HMBC) and 13C (HSQC, HMBC) NMR techniques. These data provide useful probes for determination of the site(s) of metal complexation in the drug, which are important in the mechanism of antitumour activity.

The effect of metal ions on the electrochemistry of the antitumor antibiotic streptonigrin

Anderberg, Pia I; Harding, Margaret; Lay, Peter
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Português
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46.12%
The effect of transition metal ions on the electrochemistry of 6-methoxy-5,8-quinolinedione (L1), 7-amino-6-methoxy-5,8- quinolinedione (L2) and the antitumor antibiotic streptonigrin (SN) was studied. In 10% methanol/water, the one-electron reduction of

Prevalence of diarrhoea in the community in Australia, Canada, Ireland, and the United States

Scalora, Michael; Majowicz, Shannon E; Hall, Gillian; Banerjee, Anyana; Bowman, Cara L; Daly, Leslie; Jones, Timothy; Kirk, Martyn D; Fitzgerald, Margaret; Angulo, Frederick J
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Português
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36.12%
Background: Studies in several countries have estimated the prevalence of diarrhoea in the community. However, the use of different study designs and varying case definitions has made international comparisons difficult. Methods: Similar cross-sectional telephone surveys were conducted in Australia, Canada, Ireland (including Northern Ireland), and the United States over 12 month periods between 2000 and 2002. Each survey asked about diarrhoea in the four weeks before the interview. For this comparative analysis, uniform definitions were used. Results: Questionnaires were completed for 6087 respondents in Australia, 3496 in Canada, 9903 in Ireland, and 14 647 in the United States. In the four weeks prior to interview, at least one episode of diarrhoea was reported by 7.6% of respondents in Canada, 7.6% in the United States, 6.4% in Australia, and 3.4% in Ireland. The prevalence of diarrhoea was consistently higher in females. In all countries, the prevalence of diarrhoea was highest in children <5 years and lowest in persons ≥65 years of age. When diarrhoea and vomiting was considered, the prevalence was almost identical in the four studies (range: 2.0-2.6%). Despite different health care structures, a similar proportion of respondents sought medical care (approximately one in five). Antibiotic usage for the treatment of diarrhoea was reported by 8.3% of respondents in the United States...

Hidrofobicidade de superfície celular e aderência de uma estirpe de estreptococos do grupo B durante o efeito pós-antibiótico da penicilina; Cell surface hydrophobicity and adherence of a strain of group B streptococci during the post-antibiotic effect of penicillin

Araújo, Ângela Maria Mendes; Oliveira, Ivi Cristina Menezes de; Mattos, Marcos Corrêa de; Benchetrit, Leslie C.
Fonte: Universidade de São Paulo. Instituto de Medicina Tropical de São Paulo Publicador: Universidade de São Paulo. Instituto de Medicina Tropical de São Paulo
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/08/2008 Português
Relevância na Pesquisa
36.1%
A concentração mínima inibitória e os efeitos pós-antibióticos (EPA) de um agente antimicrobiano são parâmetros que devem ser levados em consideração quando da determinação do esquema de dosagem. Os efeitos pós-antibióticos in vitro na hidrofobicidade de superfície celular e na aderência foram pesquisados em uma amostra de estreptococos do grupo B. A exposição do microrganismo por 2 h a 37 °C a 1 x CMI de penicilina induziu um EPA de 1,1 h. A carga da superfície celular da bactéria foi alterada significativamente durante a fase pós-antibiótica revelada através da capacidade de ligação ao xileno, indicada pela diminuição da hidrofobicidade. A aderência bacteriana às células epiteliais bucais humanas também foi reduzida. Os resultados da investigação demonstram que estudos clínicos destinados a determinar regimes terapêuticos deveriam incluir o conhecimento da fisiologia bacteriana durante o período pós-antibiótico.; The minimum inhibitory concentration and post-antibiotic effects of an antimicrobial agent are parameters to be taken into consideration when determining its dosage schedules. The in vitro post-antibiotic effects on cell surface hydrophobicity and bacterial adherence were examined in one strain of group B streptococci. Exposure of the microorganism for 2 h at 37 °C to 1 x MIC of penicillin induced a PAE of 1.1 h. The cell surface charge of the Streptococcus was altered significantly during the post-antibiotic phase as shown by its ability to bind to xylene: hydrophobicity was decreased. Bacterial adherence to human buccal epithelial cells was also reduced. The results of the present investigation indicate that studies designed to determine therapeutic regimens should evaluate the clinical significance of aspects of bacterial physiology during the post-antibiotic period.