Detection of methicillin resistance in Staphylococcus aureus isolated from pediatric patients: is the cefoxitin disk diffusion test accurate enough?

We evaluated the performance of several methods for the detection of methicillin resistance in Staphylococcus aureus using 101 clinical S. aureus isolates from pediatric patients in a tertiary hospital in Brazil; 50 isolates were mecA-positive and 51 were mecA-negative. The Etest and oxacillin agar screening plates were 100% sensitive and specific for mecA presence. Oxacillin and cefoxitin disks gave sensitivities of 96 and 92%, respectively, and 98% specificity. Alterations of CLSI cefoxitin breakpoints increased sensitivity to 98%, without decreasing specificity. Our results highlight the importance of a continuing evaluation of the recommended microbiological methods by different laboratories and in different settings. If necessary, laboratories should use a second test before reporting a strain as susceptible, especially when testing strains isolated from invasive or serious infections. With the new (2007) CLSI breakpoints, the cefoxitin-disk test appears to be a good option for the detection of methicillin resistance in S. aureus.

Detection of methicillin resistance in Staphylococcus aureus isolated from pediatric patients: is the cefoxitin disk diffusion test accurate enough?

We evaluated the performance of several methods for the detection of methicillin resistance in Staphylococcus aureus using 101 clinical S. aureus isolates from pediatric patients in a tertiary hospital in Brazil; 50 isolates were mecA-positive and 51 were mecA-negative. The Etest and oxacillin agar screening plates were 100 percent sensitive and specific for mecA presence. Oxacillin and cefoxitin disks gave sensitivities of 96 and 92 percent, respectively, and 98 percent specificity. Alterations of CLSI cefoxitin breakpoints increased sensitivity to 98 percent, without decreasing specificity. Our results highlight the importance of a continuing evaluation of the recommended microbiological methods by different laboratories and in different settings. If necessary, laboratories should use a second test before reporting a strain as susceptible, especially when testing strains isolated from invasive or serious infections. With the new (2007) CLSI breakpoints, the cefoxitin-disk test appears to be a good option for the detection of methicillin resistance in S. aureus.

Antibacterial resistance of community-acquired respiratory tract pathogens recovered from patients in Latin America: results from the PROTEKT surveillance study (1999-2000).

PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participated during 1999-2000; they collected 1806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1%) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3%) were penicillin-resistant and 79 (15.3%) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5%) and erythromycin (31.2%) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9%) produced beta-lactamase, ranging from 11% (Brazil) to 24.5% (Mexico). Among M. catarrhalis isolates, 138 (98.6%) produced beta-lactamase. Twenty-four (8.7%) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5% of the S. aureus isolates (Argentina 15%; Mexico 20%; Brazil 31.3%). Telithromycin was effective against 97.7% of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the beta-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy.

Antibacterial resistance of community-acquired respiratory tract pathogens recovered from patients in Latin America: results from the PROTEKT surveillance study (1999-2000)

PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participat ed during 1999-2000; they collected 1,806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1 percent) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3 percent) were penicillin-resistant and 79 (15.3 percent) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5 percent) and erythromycin (31.2 percent) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9 percent) produced b-lactamase, ranging from 11 percent (Brazil) to 24.5 percent (Mexico). Among M. catarrhalis isolates, 138 (98.6 percent) produced b-lactamase. Twenty-four (8.7 percent) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5 percent of the S. aureus isolates (Argentina 15 percent; Mexico 20 percent; Brazil 31.3 percent). Telithromycin was effective against 97.7 percent of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the b-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy

High frequency of colonization and absence of identifiable risk factors for methicillin-resistant Staphylococcus aureus (MRSA)in intensive care units in Brazil.

Colonization of hospitalized patients with methicillin-resistant Staphylococcus aureus (MRSA) is of increasing concern. To evaluate this problem in Intensive Care Units (ICUs) in Brazil, we studied 100 patients admitted to two ICUs from April to June, 1997. Of the 100 patients, 70 were male, 53 were age 60 years or older, 55 were previously hospitalized, 78 were transferred to the ICU from other hospital units, 49 had received antibiotic therapy, and 66 had undergone recent surgery. Nasal and axillary swab cultures were obtained on admission and every 48 hours thereafter until discharge. MRSA were identified by plating any cultured S. aureus on Mueller-Hinton agar containing 6 microg/ml of oxacillin. At the time of admission, 46 (46%) of the patients were colonized with MRSA. No associated risk factors for acquiring MRSA (age, previous hospitalization, prior surgery) could be identified. Of the 54 patients negative for MRSA on admission, 28 (52%) became colonized while in the ICU. Sixteen (22%) of the 74 colonized patients (colonized either on admission or during ICU stay) had associated respiratory or urinary tract infections due to MRSA, and 9 (56%) died. No correlation with special risk factors (invasive procedures, antibiotic use, age, chronic disease) was identified. MRSA occurred frequently, but there was minimal evidence of associated risk factors. Thus, control of MRSA cannot be accomplished by targeting special factors alone, but requires attention to preventing microbial spread in all areas. Of special concern is the high frequency of acquiring the organism in the ICU (52%). Education concerning the importance of hand washing, environmental surface cleaning, and barrier protection from infected patients is needed.

[Renal scintigraphy using technetium dimercaptosuccinic acid in the diagnosis of pyelonephritis in children: study of 17 cases] / Cintilografia renal com ácido dimercaptossuccínico marcado com tecnécio no diagnóstico da pielonefrite na infância: estudo de 17 casos.

OBJECTIVE: To determine whether the presence of abnormal results in DMSA renal scintigraphy indicates pyelonephritis. METHODS: We performed the washout test in 17 children with urinary tract infection, as a criterion standard, to locate the infection site. All the children underwent DMSA renal scintigraphy in the acute phase of the disease. The results were analyzed by the chi-square test or Fisher test. RESULTS: DMSA renal scintigraphy revealed changes in all five cases of pyelonephritis, suggesting acute kidney involvement. On the other hand, only one child with cystitis (total = 12 cases) had abnormal results in renal scintigraphy. Sensitivity and specificity were 100% and 92%, respectively. CONCLUSION: DMSA renal scintigraphy is a sensitive method for the diagnosis of pyelonephritis in children.

Hypertonic saline and pentoxifylline prevent lung injury and bacterial translocation after hemorrhagic shock.

Previous reports have shown beneficial effects of pentoxifylline (PTX) and hypertonic saline (HS) in the treatment of hemorrhagic shock. We compared the effects of these solutions to those of conventional lactated Ringer's (LR) treatment on bacterial translocation (BT), lung injury and total and differential cell count in the bronchoalveolar lavage fluid (BAL) after hemorrhagic shock. Rats (280-330 g) were bled to a MAP of 35 mmHg for 1 h and then randomized into 4 groups: LR (3x shed blood); HS (7,5% NaCl, 4 mL/kg); LR+PTX (25 mg/kg) and SHAM (no shock, no treatment). Additionally, total shed blood was reinfused. At 24 h lung injury was analyzed by a pathologist blinded to the groups, and a score was calculated. BT was determined by microbiological cultures of mesenteric lymph node complex. BAL was performed on a separate set of animals that received the same treatments. Lung score was significantly higher in LR group (11.5+/-1.4) as compared to HS (6.8+/-0.9), and PTX treated animals (7.2+/-0.9). The percentage of neutrophils in the BAL of LR animals (15.8%) was also significantly higher as compared with HS (5.25%) and PTX groups (9.72%). BT was noted in 50% of rats for LR group, 30% for PTX, 10% for HS and 0% for sham group. HS and PTX reduced BT and lung injury after hemorrhage. Attenuation of lung injury could be the result of less neutrophil infiltration into the lungs of HS and PTX treated animals. LR resuscitation caused pronounced lung injury and BT.

Evaluation of the in vitro activity of 9 antimicrobials against bacterial strains isolated from patients in intensive care units in brazil: MYSTIC Antimicrobial Surveillance Program.

Multi-resistant bacterial strains are increasingly prevalent in hospital environments. Bacterial resistance is an important problem, especially for practitioners in intensive care units (ICUs) because of the selective pressure on the prevalent bacteria in these environments. The MYSTIC (Meropenem Yearly Susceptibility Test Information Collection) study has been monitoring the performance of carbapenems and other antibiotics in different hospitals for at least 3 years. The in vitro activities of meropenem, imipenem, ceftazidime, cefepime, cefotaxime, ciprofloxacin, piperacilin/tazobactam, gentamicin, and tobramycin were compared against 452 recent clinical aerobic isolates. The isolates consisted of 19 species of Gram-negative bacteria (n=290) including K. pneumoniae (n=49), E. coli (n=48), A. baumannii (n=47), Enterobacter spp. (n=41), and P. aeruginosa (n=33) and 9 species of Gram-positive bacteria (n=162) including Staphylococcus aureus (n=63), Enterococcus faecalis (n=22), Streptococcus pneumoniae (n=22) and coagulase negative Staphylococci (n=21). All isolates were collected from ICU patients. Minimal inhibitory concentrations (MICs) were determined by Etest methodology, using standardized and controlled procedures. Meropenem and imipenem showed the lowest MIC(90) for all species tested. Gram-negative isolates showed the following overall resistance percentages to the other 7 drugs: tobramycin (43.1%), cefotaxime (38.6%), gentamicin (34.1%), ceftazidime (31.7%), ciprofloxacin (25.5%), piperacillin/tazobactam (26.9%), and cefepime (18.6%). Carbapenems were the most active drugs overall and only P. aeruginosa presented some degree of resistance (18.2%). We also evaluated the production of extended spectrum beta-lactamase (ESBL) among all Enterobacteriaceae members (n=176) by Etest/ESBL strip. ESBL production was detected in 51 strains (29.0%). Among them, Klebsiella pneumoniae was the most prevalent at 59.2%, followed by Enterobacter spp. (19.5%) and E. coli (14.6%). The high level of resistance against several antimicrobials and the alarming rate of ESBL production may restrict therapeutic choice to the carbapenems in this selected group of patients.

Decreased point prevalence of Haemophilus influenzae type b (Hib) oropharyngeal colonization by mass immunization of Brazilian children less than 5 years old with hib polyribosylribitol phosphate polysaccharide-tetanus toxoid conjugate vaccine in combination with diphtheria-tetanus toxoids-pertussis vaccine.

A protective herd effect has been described after susceptible populations of children are vaccinated with conjugate Haemophilus influenzae type b (Hib). Hib carriage was studied in children aged 6-24 months attending day care centers in two cities in southern Brazil (Curitiba and Porto Alegre). In Curitiba, routine immunization with Hib polyribosylribitol phosphate polysaccharide-tetanus toxoid conjugate vaccine (PRP-T) in combination with diphtheria-tetanus toxoids-pertussis vaccine (PRP-T/DTP) has been offered since September 1996; DTP vaccine alone is routinely given in Porto Alegre. Children in Porto Alegre (n=643) were 8 times less likely to have received adequate Hib vaccination and 4 times more likely to be Hib carriers than children in Curitiba (n=647; i.e., point prevalence of oropharyngeal colonization, 4.8% vs. 1.2%). Point prevalence of carriage with non-type b or other nontypeable Hi was similar in children of both cities. There was a vaccination effect on carriage rates in children who received a primary 3-dose series, independent of the booster dose, suggesting that a booster may be unnecessary to induce population protection.

[Evaluation of polymorphonuclear neutrophils in moderate malnutrition]. / Avaliação de neutrófilos na desnutrição moderada.

PURPOSE: To evaluate the phagocytic function of polymorphonuclear neutrophils in moderate malnutrition. METHODS: The phagocytic function of neutrophils obtained through peripheral blood sampling of twenty two children with moderate malnutrition without infections was analyzed. The results were compared to a group of twenty well nourished children matched for age (two to five years old). The phagocytic function was assessed by the ingestion of zymosan particles and nitro blue tetrazolium reduction among 200 cells. RESULTS: The mean number of zymosan particles ingested by neutrophils incubated with homologous human serum and autologous human serum were 18, 41 and 46 in the malnutrition group compared to 20, 57 and 63 in the well nourished group. The spontaneous and stimulated reduction of nitro blue tetrazolium was 6 and 11 in the malnourished patients, respectively, and 12 and 17 in the well nourished group. CONCLUSION: A decrease in the process of ingestion and digestion during phagocytosis occurs in malnourished patients.

Avaliaçäo de neutrófilos na desnutriçäo moderada / Evaluation of polymorphonuclear neutrophils in moderate malnutrition

Objetivo. Avaliar a etapa de ingestao da fagocitose e do metabolismo oxidativo de neutrófilos em crianças portadoras de desnutriçao moderada. Métodos. Foi analisado o sangue periférico de vinte e duas crianças portadoras de desnutriçao moderada, sem infecçao, comparando-se os resultados aos de vinte crianças eutróficas da mesma faixa etária (2 a 5 anos de idade). A ingestao fagocitária por neutrófilos foi avaliada através da ingestao de partículas de zimosan e o metabolismo oxidativo avaliado pela reduçao do nitro blue tetrazolium entre um número fixo de 200 neutrófilos. Resultados. As médias aritméticas da ingestao por neutrófilos de partículas de zimosan, zimosan incubado com soro homólogo e zimosan incubado com soro autólogo foram 18, 41 e 46 em desnutridos e 20, 57 e 63 em eutróficos. A reduçao espontânea e estimulada de nitro blue tetrazolium foi de 6 e 11 em desnutriçao e 12 e 17 em eutróficos. Conclusao. Concluiu-se haver uma diminuiçao da etapa da ingestao e do metabolismo oxidativo de neutrófilos nos pacientes estudados portadores de desnutriçao moderada.

[Acute diarrhea in children less than 3 years of age: Enteropathogens isolated in patient's stools, compared with a control group] / Diarréia aguda em crianças menores de 3 anos de idade: recuperação de enteropatógenos nas amostras fecais de pacientes comparada à de grupo controle.

OBJECTIVES: To observe the occurrence of different etiological agents of acute diarrhea (AD) in stool specimens of patients and children in a control group. MATERIAL AND METHODS: 100 children less than three years of age with AD were studied as well as 100 controls, between November 1993 and May 1994. Stool specimens were collected in both groups and the following enteropathogens were searched for: Rotavirus, Escherichia coli (EPEC, ETEC, EIEC, EHEC), Salmonella sp, Shigella sp, Campylobacter jejuni, Campylobacter coli, Yersinia enterocolitica, Cryptosporidium sp, Giardia lamblia, Entamoeba histolytica. Statistical analysis using the exact Fisher test (at significance level p<0,05) was done. The mean age was 12,5 months, with more cases in patients less than 6 months (35%). Children were seen at the emergency section on an average fifth day after the start of the diarrhea. Most came from homes with basical sanitary conditions. Watery diarrhea was more frequent than bloody diarrhea with mucus, at a proportion of 4:1. RESULTS: Rotavirus was the most frequent agent: 21% in the AD group and 3% in the control group (p= 0,0001). Shigella sp was isolated in 7% of the AD group and none of the control group (p= 0,0140). EPEC was detected in 13% of AD cases and 7% in the control group (p= 0,2381) but the classical subgroups O55, O111, O119 were only isolated from the patients with AD. The other enteropathogens were infrequently detected or in equal proportion in both groups. Rotavirus and EPEC were the more frequently isolated agents in watery diarrhea, while Shigella sp was the predominant agent found in bloody stools with mucus. CONCLUSIONS: Rotavirus was the most common causative agent in AD. The detection of Rotavirus and Shigella sp nearly exclusively in patients with AD confirms the high patogenicity of these etiological agents when compared to the others. Escherichia coli (EPEC) diagnosed by polyvalent sera does not confirm its respective diarrheogenic property due to isolation in the same proportion among patients with AD and controls. Monovalent antisera made possible the detection of classical subgroups of EPEC O111, O119, O55 isolated only from AD patients, confirming the already known high patogenicity of these strains.

[In vitro antimicrobial activity of cefpirome compared to other broad-spectrum beta-lactam drugs against 804 clinical isolates from 9 Brazilian hospitals]. / Atividade antimicrobiana in vitro da cefpiroma em comparação com outros beta-lactâmicos de amplo espectro contra 804 amostras clínicas de nove hospitais brasileiros.

OBJECTIVE: To evaluate the in vitro activity of the fourth-generation cephalosporin cefpirome in comparison to that of ceftazidime, ceftriaxone, cefotaxime and imipenem in a multicenter study involving nine hospitals from six cities (four States). MATERIAL AND METHOD: A total of 804 isolates from patients hospitalized in either intensive care units or Oncology/Hematology units was evaluated. The isolates were collected between June and November of 1995, i.e. before cefpirome became commercially available in Brazil, and susceptibility tested by broth microdilution following the NCCLS procedures. All isolates resistant to cefpirome were retested by E-test. RESULTS: Against Enterobacteriaceae (n = 344), cefpirome demonstrated an activity 2 to 32-fold higher than that of the third-generation cephalosporins (TGCs) and similar to that of imipenem. The percentages of Enterobacteriaceae susceptible were: 88%, 69% and 96% for cefpirome, TGCs and imipenem, respectively. The cefpirome spectrum was greater or equal than that of imipenem against Citrobacter freundii, Enterobacter aerogenes, Morganella morganii and Serratia marcescens. Against Acinetobacter sp. (n = 77), cefpirome was slightly more active than ceftazidime; however, the percentages of isolates resistant to these compounds were high (84% and 88%, respectively). The activities of cefpirome, ceftazidime and imipenem were very similar against P. aeruginosa isolates (n = 128), with MIC50(mg/ml)/percent susceptible of 8/59%, 8/62% and 4/62% respectively. Against aerobic gram-positive bacteria, the cefpirome activity was 4 to 16-fold higher than that of TGCs but 2 to 8-fold lower than that of imipenem. CONCLUSION: The results suggest that, in Brazil, cefpirome has a spectrum of activity which is higher than that of the TGCs against aerobic gram-negative (Enterobacteriaceae and non-Enterobacteriaceae) and gram-positive bacteria and similar to that of imipenem against some Enterobacteriaceae species and P. aeruginosa.

Atividade antimicrobiana in vitro da cefpiroma em comparaçäo com outros beta-lactâmicos de amplo espectro contra 804 amostras clínicas de nove hospitais brasileiros / Antimicrobial activity of cefpirome compared to other broad-spectrum beta-lactam drugs against 804 clinical isolates from 9 Brazilian hospitals

Objetivo. Avaliar a atividade in vitro da cefalosporina de quarta geraçao, cefpiroma em comparaçao com ceftazidima, ceftriaxona, cefotaxima e imipenem em um estudo multicêntrico envolvendo nove hospitais de seis cidades em quatro estados. Material e Métodos. Foram estudadas 804 amostras clínicas isoladas em pacientes internados em unidades de terapia intensiva ou unidades de oncohematologia. As amostras foram coletadas no período de junho a novembro de 1995, isto é, antes da cefpiroma estar disponível comercialmente no Brasil, e testadas através do método de microdiluiçao em placas conforme descrito pelo National Committee for Clinical Laboratory Standards (NCCLS). Todas as amostras resistentes à cefpiroma foram retestadas utilizando-se o E-test. Resultados. Contra as amostras de enterobactérias (n=344), a cefpiroma apresentou atividade de 2 a 32 vezes superior àquela apresentada pelas cefalosporinas de terceira geraçao (CTGs) e semelhnate àquela apresentada pelo imipenem. As porcentagens de enterobactérias sensíveis foram: 88 por cento para a cefpiroma, 69 por cento para as CTGs e 96 por cento para o imipenem. O espectro de açao da cefpiroma foi maior ou igual ao do imipenem contras as espécies Citrobacter freundii, E. aerogenes, Morganella morganii e Serratia marcescens. Contra Acinetobacter sp. (n=77), a cefpiroma foi ligeiramente mais ativa que a ceftazidima, porém as porcentagens de resistência foram muito altas para esses compostos (84 por cento e 88 por cento respectivamente). As atividades da cefpiroma, ceftazidima e imipenem foram semelhantes contra Pseudomonas aeruginosa (n=128), com MIC50/porcentagem de sensibilidade de 8/59 por cento, 8/62 por cento e 4/62 por cento respectivamente. Contra bactérias aeróbias gram-positivas, a cefpiroma foi de 4 a 16 vezes mais ativa que as CTGs. Contra S. epidermidis e outras espécies de estafilococos coagulase-negativos a cefpiroma foi ligeiramente superior ao imipenem, porém, contra as outras espécies de bactérias gram-positivas avaliadas, o imipenem apresentou atividade um pouco superior. Conclusao: Os resultados desse estudo sugerem que, no Brasil, a cefpiroma apresenta espectro de açao superior ao das CTGs contra bactérias gram-negativas (Enterobacteriaceae e nao fermentadares) e gram-positivas e semelhante ao do imipenem contra algumas espécies de enterobactérias e contra P. aeruginosa.

Oropharynx microbiota among alcoholics and non-alcoholics.

CONTEXT: The oropharynx microbiota plays an important role in the origin of infections, especially among alcoholics whose airway defenses are impaired. OBJECTIVE: To compare the normal oropharingeal flora in heavy alcohol drinker and non-alcoholics. PATIENTS: 117 persons, 58 heavy alcohol drinkers and 59 non-alcoholics. SETTING: Santa Casa de São Paulo Emergency Service. DESIGN: A blind prospective study. MAIN OUTCOMES MEASURES: Prevalence of aerobic and anaerobic bacteria, and fungi. RESULTS: The study of the oropharynx microbiota among heavy alcohol drinkers demonstrated the presence of anaerobic microorganisms in 84.5% of them, including: Bacteroides sp, Prevotella melaninogenica, Fusobacterium sp, Veilonella sp, Peptostreptococcus sp, Propionibacterium sp, Bifidobacterium sp and Clostridium sp, versus 30.5% (p < 0.005) of non-alcoholics. Candida sp was present in 34.5% of heavy alcohol drinkers and 5.1% of non-alcoholics (p < 0.005). Enterobacteria predominated among heavy alcohol drinkers (25%) compared with non-alcoholics (5.5%) only in the age group 14 to 34 years (p < 0.05). CONCLUSION: Based upon these results, it was possible to conclude that the knowledge of the oropharynx microbiota among heavy drinkers and non-alcoholics has an important predictive value concerning probable etiologic agents of lower airway infections. Infections caused by anaerobic microorganisms and fungi should be taken into consideration during the choice of empirical therapy for heavy alcohol drinkers.

Evaluation of the Antimicrobial Activity of Sparfloxacin, Relative to Other Oral Antibiotics Against 1,125 Bacterial Isolates from 10 Medical Centers in Brazil.

A multicenter study was carried out in order to compare the in vitro activity of sparfloxacin to ciprofloxacin, amoxicillin/clavulanic acid, cephalexin, cefuroxine and azithromycin, against 1,125 microorganisms recently isolated from clinical specimens, most of them representative of respiratory tract infections. Sparfloxacin demonstrated potent action and was more active than the beta-lactam agents and azithromycin against most of the bacterial strains tested. Sparfloxacin was more potent (96% and 95% sensitivity, with MIC(90) of 0.19µg/mL and 0.5µg/mL, respectively)than the other antimicrobial agents tested against the Enterobacteriaceae family (Escherichia coli and Elebsiella pneumoniae). It was found to be equivalent in activity to ciprofloxacin (96% and 91% sensitivity and MIC(90) of 0.25 and 0.75µg/mL, respectively). Sparfloxacin was also found to be very active against the most fastidious microorganisms commonly associated to respiratory tract infections such as the penicillin-susceptible and resistant Streptococcus pneumoniae (MIC(90) 0.5µg/mL and 0.38µg/mL, respectively), ampicillin-susceptible and -resistant Haemophilus influenzae (MIC(90) 0.016µg/mL and 0.38µg/mL, respectively), beta-lactamase producing Moraxella catarrhalis (MIC(90) 0.032µg/mL) and non beta-lactamase producing M.catarrhalis (MIC(90) 0.5µg/mL).

Endotoxin exposure and symptoms in asthmatic children.

Endotoxins (ET) are pro-inflammatory substances present in house dust which may increase non-specific bronchial reactivity in asthmatic patients. Endotoxins (EU/g) and Der p 1 levels were compared in the homes of ten asthmatic and ten control children, aged 6-16 years, living in São Paulo, Brazil. The houses were visited once a month from February 1993 to February 1994 and dust samples were collected from the bedding and floor of each subject's house. No significant differences were observed in ET and Der p 1 levels in the homes of asthmatics and controls. The highest ET levels were detected in January and November, whereas the lowest levels were detected in April and August (p < 0.05), demonstrating a distinct seasonal distribution. The highest Der p 1 levels in bedding were observed in July and the lowest in February (p < 0.05), while Der p 1 levels in floor did not show significant differences throughout the year. Symptom and medication scores were evaluated monthly in the group of asthmatic children. There was a significant correlation (p < 0.05, r = 0.63) between clinical symptom scores and ET exposure, however no significant correlation was found for mite exposure (p > 0.05, r = 0.19). The results suggest that ET exposure exacerbates asthmatic symptoms in mite allergic, asthmatic children.

Evaluation of the in vitro activity of cefepime compared to other broad-spectrum cephalosporins against clinical isolates from eighteen Brazilian hospitals by using the Etest.

The in vitro activity of cefepime was compared to that of ceftazidime, ceftriaxone, and cefotaxime in a multicenter study involving 10 clinical microbiology laboratories and clinical isolates from 18 Brazilian hospitals from 7 cities (4 states). A total of 982 isolates consecutively collected between December 1995 and March 1996 were susceptibility tested by using Etest and following the NCCLS procedures for agar diffusion tests. The cefepime spectrum was broader than that of the other broad-spectrum cephalosporins against both Gram-negative rods and Gram-positive cocci. Cefepime was particularly more active against Enterobacter sp. (MIC90, 2 micrograms/ml), Serratia sp. (MIC90, 2 micrograms/ml) and oxacillin-susceptible Staphylococcus aureus (MIC90, 3 micrograms/ml). Against Pseudomonas aeruginosa, cefepime (MIC90, 16 micrograms/ml) was slightly more active than ceftazidime (MIC90, 32 micrograms/ml) and 8- to 16-fold more active than ceftriaxone of cefotaxime (MIC90, > 256 micrograms/ml). Our results show that nosocomial bacteria, especially Gram-negative rods, have a high rate of cephalosporin resistance in Brazil. However, part of these resistant bacteria remains susceptible to cefepime. The Etest was shown to be an excellent method for multicenter studies of the in vitro evaluation of new antimicrobial agents.

Comparative in vitro Activity of Meropenem Versus Other Extended-Spectrum Antimicrobial Agents Against 2,085 Clinical Isolates Tested in 13 Brazilian Centers.

Meropenem is a parenteral carbapenem antibacterial agent with a very broad spectrum of antibacterial activity. It is the second agent of its class to become available in Brazil. The in vitro antibacterial activity of meropenem was compared with imipenem and four other antimicrobial agents in a multicenter study. This study involved 13 clinical microbiology laboratories, 10 of which came from 8 Brazilian states. A total of 2,085 clinical isolates consecutively collected between December 1995 and March 1996 were susceptibility tested using the Etest and following the NCCLS procedures. Meropenem inhibited more than 90% of isolates of Enterobacteriaceae at 0.5 µg/mL, except for Citrobacter sp. (1 µg/ml). Generally, meropenem was slightly more active than imipenem against Gram-negative organisms and its spectrum of antimicrobial activity was broader than those of all other drugs tested. Against Pseudomonas aeruginosa, meropenem (MIC50, 0.38 µg/ml) was approximately 8-fold more active than imipenem (MIC 50,3 µg/mL). Imipenem was two-to eight-fold more active than meropenem against some Gram-positive specees oxacillin, including Enterococcus faecalis (MIC 50 of 0.75 µg/mL and 2 µg/mL respectively), oxacillin-susceptible Staphylococcus aureus (MIC 50 of 0.47 &mul;g/mL and 0.094 µg/mL), oxacillin-susceptible Staphylococcus epidermidis (MIC 50 of 0.064 µg/mL and 0.5mg/mL). Against Streptococcus sp. meropenem was slightly more active than imipenem (MIC 50, 0.016 µg/mL). The results of this study may be used to guide empiric therapy in Brazil and indicates that meropenem may have an important role in the treatment of infections caused by multiresistant strains of bacteria.