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PubMed1989

Randomized efficacy trials of long-acting oxytetracycline in neonatal pigs.

Prophylactic efficacy of 100 mg of long-acting oxytetracycline (OTC) given IM to neonatal pigs within 12 hours of birth was evaluated in a swine herd. The herd had a history of increased neonatal mortality, diarrhea, foot abscess, and arthritis in nursing pigs. Two trials were conducted in which liters and individual pigs were the treatment groups of interest. In both trials, OTC treatment failed to reduce mortality, diarrhea, or arthritis or the need for subsequent antimicrobial therapy (P greater than 0.05). Preweaning weight gains were not increased (P greater than 0.05) in treated pigs. However, in the individual pig trial, foot abscess rates were significantly (P = 0.01) lower in treated pigs (3.7%) than in nontreated pigs (8%). Aerobic bacteria isolated from pigs with diarrhea, arthritis, or foot abscess had minimum inhibitory concentrations for OTC greater than or equal to 64 micrograms/ml or were classed as resistant on the basis of disk-diffusion tests.

Abscess↗
PubMed2006

Spectrum and the susceptibilities of microbial isolates in cases of congenital nasolacrimal duct obstruction.

PURPOSE: To determine the microbial profile of congenital nasolacrimal duct obstruction (CNLDO) and the appropriate antimicrobial agents based on the sensitivity pattern of the isolated microorganisms. METHODS: Two hundred thirty-eight eyes of 187 young children in the age group of 0-5 years with CNLDO were included in the study. A group of 40 children (80 eyes) who had attended the hospital for other ocular disorders was considered a control. Material obtained from the lacrimal sac was cultured, and infectious agents were isolated. Susceptibility testing was done by Kirby-Bauer disk diffusion method for 7 different antibiotics. Fisher's exact test was used to look for statistical associations between the age group, the type of discharge, and the type of microorganisms isolated. RESULTS: Of the 238 samples with a clinical diagnosis of CNLDO, 197 (83%) yielded a positive culture. There was no growth in 41 samples (17%). Altogether, there were 217 isolates. One hundred twenty-four (57%) isolates were Gram-positive bacteria, the most frequent isolate being Streptococcus pneumoniae. Gram-negative bacteria accounted for 93 (43%) of the isolates, the most frequent isolate being Haemophilus influenza. There was one fungal isolate (0.5%) of Candida tropicalis. Gram-positive bacteria were sensitive to chloramphenicol, vancomycin, and ofloxacin and Gram-negative bacteria to ofloxacin and ciprofloxacin. CONCLUSIONS: Chronic dacryocystitis caused by CNLDO is associated with an almost-equal proportion of Gram-positive and Gram-negative bacteria. Ofloxacin topical drops can be used in the treatment of cases with CNLDO.

Anti-Bacterial Agents↗
PubMed1984

Evaluation of the AutoMicrobic system for identification and susceptibility testing of gram-negative bacilli.

The AutoMicrobic system (AMS) (Vitek Systems, Inc., Hazelwood, Mo.) was compared with the API-20E system for the identification of gram-negative bacilli by using 380 stock clinical isolates and 377 immediately encountered fresh clinical isolates. For the stock isolates, with Enterobacteriaceae-Plus Biochemical Cards and automated interpretation, 364 (95.8%) were in agreement to the species level. For the fresh clinical isolates, agreement at the genus and species levels was 89.7 and 85.9%, respectively, when Enterobacteriaceae-Plus Cards were interpreted by the AMS. Manual interpretation of Enterobacteriaceae-Plus Biochemical Cards improved species level agreement to 91.0%. Subsequent retesting of all discrepant isolates with the Gram-Negative Identification Card resulted in significant improvement of results, and for the stock and fresh clinical isolates, species level agreement was 98.7 and 97.3%, respectively. AMS susceptibility testing was evaluated by comparing ampicillin and cephalothin MICs determined in parallel by AMS and a reference broth microdilution test for stock isolates, and by comparison of AMS and standardized disk agar diffusion test results for fresh clinical isolates. For the stock isolates, AMS mean integer MICs approximated microdilution mean integer MICs with AMS, providing excellent MIC replicability. For ampicillin and cephalothin, 50 and 46.8%, respectively, of AMS integer MICs were within +/- 1 microgram/ml of the reference values, and 89.3 and 63.1% of AMS integer MICs were within +/- 2 micrograms/ml of the reference values. For the fresh clinical isolates, AMS and reference results were in disagreement for 4.5% of the antimicrobial agents tested, with 2.3% as a combination of "major" and "very major" errors.

Ampicillin↗
PubMed2006

Antimicrobial activity of Sapindus mukorossi and Rheum emodi extracts against H pylori: In vitro and in vivo studies.

AIM: to evaluate the antibacterial activity of Sapindus mukorossi (S. mukorossi) and Rheum emodi (R. emodi). METHODS: Powders of S. mukorossi and R. emodi were extracted successively with petroleum ether, benzene, chloroform and ethanol and were concentrated in vacuum. The disk diffusion method was used for in vitro studies and in vivo studies were performed on male Wister rats. Thirty resistant clinical isolates of H pylori, as determined by their antibiotic sensitivity patterns by E-test, along with two Gram +ve (S. aureus, B. subtilis) and two Gram -ve (E. coli, P. vugaris) organisms were screened for their susceptibility patterns against these extracts. RESULTS: In our screening, all 30 resistant isolates and the other four organisms (two Gram +ve S. aureus, B. subtilis and two Gram -ve, E. coli, P. vugaris) were sensitive to the test compounds. It was found that ethanol and chloroform extracts of S. mukorossi and ethanol and benzene extracts of R. emodi inhibited H pylori at very low concentrations. In the in vitro study, the isolates showed a considerable zone of inhibition at very low concentrations (10 mug/mL) for both the extracts. In the in vivo study, the H pylori infection was cleared with minimal doses of extracts of S. mukorossi (2.5 mg/mL) and R. emodi (3.0 mg/mL) given orally for seven days. CONCLUSION: We can conclude from this study that the extracts of S. mukorossi and R. emodi inhibited the growth of pylori in vitro and, in in vivo studies, the H pylori infection cleared within seven days at very low concentrations. We also found that H pylori did not acquire resistance against these herbal extracts even after 10 consecutive passages.

Animals↗
PubMed2000

Primary and combined resistance to four antimicrobial agents in Helicobacter pylori in Sofia, Bulgaria.

The aim of this study was to evaluate the primary and combined resistance of Helicobacter pylori against four antimicrobial agents by a screening agar method (SAM) and a modified disk diffusion method (MDDM) alone and in combination. Pre-treatment H. pylori isolates from 192 consecutive H. pylori-positive patients at three hospitals in Sofia were investigated. MDDM was performed with disks containing metronidazole (5 microg), clarithromycin (15 microg) or erythromycin (15 microg), ciprofloxacin (5 microg) and tetracycline (30 microg). Resistance was determined by an inhibitory zone of <16 mm for metronidazole and < or =30 mm for other agents tested. The cut-off concentrations used to define resistance by SAM were: metronidazole >8 mg/L, clarithromycin >2 mg/L, tetracycline >4 mg/L and ciprofloxacin >1 mg/L. Primary resistance rates in H. pylori were: metronidazole 28.6%, clarithromycin 9.7%, metronidazole + clarithromycin 2.8%, ciprofloxacin 3.9%, metronidazole + ciprofloxacin 2.3%, tetracycline 1.9% and metronidazole + tetracycline 1.2%. Among metronidazole-resistant isolates, combined resistance to clarithromycin, ciprofloxacin and tetracycline was present in 11.4% (5 of 44 strains), 8.3% (3 of 36) and 4.9% (2 of 41), respectively. Two strains exhibited triple resistance to macrolides, metronidazole and either ciprofloxacin or tetracycline. Three tetracycline-resistant strains were detected in 1999; however, resistance rates to other agents were relatively stable during the 6 years. Primary H. pylori resistance to metronidazole is moderate and resistance to clarithromycin and to ciprofloxacin is considerable in comparison with results in most other countries. The alarming appearance of strains harbouring combined resistance or multiresistance provides the motivation for continued surveillance of H. pylori at global, national and regional levels.

Adolescent↗
PubMed1988

[Sensitivity of clinical strains of facultatively anaerobic bacteria to antimicrobial drugs].

Six hundred and sixty five samples of clinical materials from patients with various pyoinflammatory diseases were tested for obligatory anaerobes. Anaerobes were detected in 148 samples which amounted to 22.3 per cent of the total number of the samples and to 33.2 per cent of the samples with microbial growth. A total of 171 strains of obligatory anaerobes were isolated. Among them 58.5, 24.5, 16.4 and 0.6 per cent were nonsporulating gramnegative bacilli, grampositive cocci, grampositive bacilli and gramnegative cocci respectively. Sensitivity of the isolated anaerobes was tested with the disk diffusion method. The most active drugs against the tested strains were: nitroxoline, rifampicin, metronidasole, erythromycin, carbenicillin and cefotaxim (4.2, 4.5, 9.3, 10.6, 11.5 and 11.7 per cent of the resistant strains respectively). Gentamicin, polymyxin M, novobiocin and cefazoline were the least active drugs (94.6, 78.9, 65.4 and 50.0 per cent of the resistant strains respectively). Metronidasole, levomycetin, nitroxolin, rifampicin and furazolidone showed the highest activity against bacteroids of the fragilis group (0, 0, 0, 8 and 12.5 per cent of the resistant strains respectively) while gentamicin, polymyxin M, cefazolin, oxacillin, novobiocin and penicillin showed the lowest activity (100, 100, 100, 100, 87.0 and 66.7 per cent of the resistant strains respectively).

Anti-Bacterial Agents↗
PubMed2026

Antimicrobial resistance in Staphylococcus pseudintermedius isolated from asymptomatic and symptomatic dogs in Montevideo, Uruguay: characterization of MRSP strains and genetic determinants of resistance.

Staphylococcus pseudintermedius&#xa0;is a common opportunistic pathogen in dogs and an increasing concern in veterinary medicine due to rising antimicrobial resistance, particularly to methicillin. This study aimed to characterize resistance profiles and genetic mechanisms in isolates from healthy and diseased dogs in Montevideo, Uruguay. A total of 133 isolates was analyzed (83 from clinical infections and 50 from asymptomatic carriers). Antimicrobial susceptibility was assessed by disk diffusion following veterinary guidelines. Resistance genes and SCCmec types were detected by PCR. Ten representative isolates underwent whole genome sequencing. High resistance rates were observed for penicillin (81%), erythromycin (49.6%), and clindamycin (45%). Overall, 48.9% of isolates were multidrug-resistant. Phenotypic resistance to oxacillin was detected in 26% of isolates; however, 23% carried mecA gene and were therefore classified as genotypic MRSP. These isolates were more frequent among dogs with clinical infections. These strains showed higher resistance to all antimicrobials tested. SCCmec type V was the most prevalent, and greater genetic diversity was found among isolates from symptomatic dogs. Genomic analysis revealed circulating strains of unassigned sequence types (STs), a variety of resistance genes within specific lineages, the circulation of SCCmec XIV cassette carrying strains, and an Oxacillin-susceptible Methicillin-resistant Staphylococcus pseudintermedius (OS-MRSP) isolate. These findings demonstrate the clinical and epidemiological relevance of&#xa0;S. pseudintermedius&#xa0;in Uruguay and the role of asymptomatic dogs as reservoirs of resistant strains. The results emphasize the need for surveillance, prudent antimicrobial use, and integrated control strategies within a One Health framework.

Animals↗
PubMed1983

Evaluation of the cefonicid disk test criteria, including disk quality control guidelines.

Cefonicid (SKF 75073) is a second-generation cephalosporin which has a spectrum of antimicrobial activity similar to that of cefamandole, but cefoxitin (a cephamycin) and cephalothin have uniquely different spectra of activity. The second-generation cephalosporins tested displayed comparable susceptibility to beta-lactamases and inhibited type I beta-lactamases. Although cefonicid has a longer serum half-life (3 to 4 h) compared with the currently used drugs, the same minimal inhibitory concentration breakpoints separating susceptible and resistant categories were applied to tests with cefonicid, cefamandole, and cephalothin. Regression analysis of the disk diffusion test results confirmed the use of identical zone size breakpoints for 30-micrograms cefonicid, cefamandole, and cephalothin disks: all three produced similar parabolic regression lines. Further analysis of disk test data confirmed the fact that cefonicid and cefamandole disks might be used interchangeably. But for routine tests, cefonicid disks might be preferred in order to minimize the number of very major (false-susceptible) interpretive errors. Suggested cefonicid 30-micrograms disk interpretive criteria are: susceptible, greater than or equal to 18 mm (less than or equal to 8.0 micrograms/ml), and resistant, less than or equal to 14 mm (greater than 16 micrograms/ml). Quality control zone diameter limits were calculated from data obtained in a multilaboratory collaborative study.

Bacteria↗
PubMed2005

Antimicrobial-resistant Shigella sonnei: limited antimicrobial treatment options for children and challenges of interpreting in vitro azithromycin susceptibility.

BACKGROUND: Antimicrobial-resistant Shigella sonnei is a growing problem in the United States and poses treatment challenges particularly among children. Azithromycin is recommended as an alternative oral agent for shigellosis. METHODS: All isolates of Shigella submitted to Johns Hopkins clinical laboratory during the outbreak year (2002) were compared with a historical comparison group (1996-2000). Isolates were considered multiresistant if they were resistant to ampicillin and trimethoprim-sulfamethoxazole (TS). Selected outbreak and reference isolates were tested for azithromycin susceptibility by E-test, disk diffusion and broth dilution methods. RESULTS: Between 1996-2000, among the 111 isolates submitted, 63% were from pediatric patients; 63% of isolates were resistant to ampicillin and 12% to TS. In 2002, among the 205 isolates submitted, 82% were from pediatric patients; 91% isolates were resistant to ampicillin and 67% to TS. The proportion of multiresistant isolates increased from 6% in 1996 to 65% in 2002 (P < 0.05). Azithromycin susceptibility by E-test and disk diffusion demonstrated 2 zones of inhibition for S. sonnei. Interpretation using the inner zone resulted in higher MICs (minimal inhibitory concentration) compared with the outer zones by E-test (P < 0.0001) and disk diffusion (P < 0.0001). CONCLUSIONS: With increasing interest in using azithromycin for shigellosis, clinical laboratories should be aware of the interpretation difficulty caused by the dual-zone phenomenon seen with E-test and disk diffusion methods for S. sonnei.

Adolescent↗
PubMed1994

National survey of methicillin-resistant Staphylococcus aureus in Belgian hospitals: detection methods, prevalence trends and infection control measures. The Groupement pour le Dépistage, l'Etude et la Prévention des Infections Hospitalières.

A questionnaire survey of Belgian acute care hospitals was conducted to determine the methods used for detection of methicillin-resistant Staphylococcus aureus (MRSA), to estimate the prevalence of this organism during the period 1989-1991 and to describe the infection control measures used locally for limiting its spread. Questionnaires were returned by 144 acute care hospitals, with a coverage of 41 to 72% of hospitals by province. Methods used for detection of MRSA included disk diffusion (91%), microdilution panels (8%) and oxacillin agar screen (9%). Only 34% of laboratories performed disk diffusion testing under optimal conditions for detection of heterogenous resistance. Among 36 hospitals reporting complete susceptibility data of Staphylococcus aureus isolates tested during the study period (n = 24,153), a mean MRSA prevalence of 14% was found (range: 0-70%). The median prevalence increased from 9.5% in 1989 to 13.7% in 1991 and showed a significant linear increase during this period in 30% of these hospitals (p < 0.01). Precautions used for controlling spread of MRSA included hand decontamination using either soap and water or antimicrobial preparations (68% of hospitals), room decontamination (62%), patient isolation (55%) and various barrier precautions (24-49%). Carrier screening was performed in 37% of hospitals, but antibiotic decolonization was attempted in only 24%. This survey identified areas for improvement in MRSA detection methods and underscored the need for multicentric surveillance of MRSA prevalence and a reappraisal of MRSA control strategies in Belgian hospitals.

Bacteriological Techniques↗
PubMed1995

Disk diffusion susceptibility tests: need for laboratory-specific breakpoints.

Significant changes were observed in the measured resistance levels of Escherichia coli and Staphylococcus aureus when the Biodisk disk susceptibility test method used in 1992 was replaced with another commercial method, Oxoid. For example, when non-species-specific breakpoints were used, the frequency of cephalotin-resistant E. coli was 12% of all isolates in 1992 but only 4% in 1993; the corresponding figures for the intermediately resistant isolates were 84% and 8%. The population distribution histograms were however, practically unchanged. Thus, the resistance percentages apparently did not reflect the real development of resistance. Similar findings were also made for several other antimicrobials. Susceptibility test breakpoints should therefore be examined separately for all bacterial species in each laboratory, and the application of adjusted laboratory-specific breakpoints should be considered. For this purpose, the WHONET computer program provides excellent assistance.

Ampicillin↗
PubMed1999

[Susceptibility to selected antibiotics of Yersinia enterocolitica 03 strains, carrying and not carrying plasmid pYV].

A total of 199 clinical strains of Yersinia enterocolitica serotype O3, biotype 4 were tested for their susceptibility to antibiotics (158 strains carried the virulence plasmid pYV and 41 strains did not). 114 isolates were tested by standard disk diffusion method for 21 antibiotics. Almost all tested strains were resistant to ampicillin and cefazolin and susceptible to amoxycillin/clavulanate, cefaclor, cefamandole, cefuroxime, cefotaxime, ceftriaxone, aztreonam, imipenem, gentamicin, amikacin, netilmicin, tetracycline, doxycycline, chloramphenicol, ciprofloxacin, sulphamethoxazole, co-trimoxazole, trimethoprim and furazolidone. In addition minimal inhibitory concentrations (MICs) of 15 antibiotics were determined by agar dilution method for all 199 strains (158 plasmid positive and 41 strains plasmid negative). Third-generation cephalosporins such as cefotaxime and ceftriaxone and a fluoroquinolone (ciprofloxacin) were the most active antimicrobial agents, tested followed by aztreonam, imipenem, trimethoprim, tetracycline, gentamicin, chloramphenicol, amoxycillin/clavulanate, cefaclor, cefuroxime, amikacin, furazolidone and sulphamethoxazole. The present study demonstrated a high susceptibility of clinical strains of Y. enterocolitica to most of the tested antibiotics. In general, there was no significant difference between susceptibility of virulence plasmid pYV positive and virulence plasmid negative strains to antibacterial agents.

Drug Resistance, Microbial↗
PubMed1994

Antimicrobial activity of beta-lactams against multiresistant micro-organisms from the family Enterobacteriaceae, and genus Pseudomonas.

The antimicrobial activity of twenty beta-lactams was determined against multiresistant micro-organisms from the Enterobacteriaceae family (450) and the genus Pseudomonas (90). The antimicrobial susceptibility was assessed by the disk diffusion method. The most effective antibiotics were cephalosporins of the second and third generation, and non-classical beta-lactams (imipenem and moxalactam). A pronounced resistance was found to carbenicillin, ampicillin, cephalotin and cefazolin. These resistance patterns corresponded to a high consumption of these antibiotics.

Anti-Bacterial Agents↗
PubMed2004

Beta-lactam susceptibilities and prevalence of ESBL-producing isolates among more than 5000 European Enterobacteriaceae isolates.

In vitro susceptibility to 15 beta-lactam antibiotics was evaluated using Enterobacteriaceae isolated during the SENTRY Antimicrobial Surveillance Program. Piperacillin/tazobactam was the most active penicillin against Escherichia coli, Proteus mirabilis, Klebsiella oxytoca and Klebsiella pneumoniae (94.9%, 98.3%, 87.4% and 82.9% of isolates susceptible). Of the cephalosporins, cefepime was most effective against Escherichia coli, Proteus mirabilis and Enterobacter cloacae (99.2%, 96.3% and 95.2% of isolates susceptible, respectively) and cefoxitin against Klebsiella oxytoca and Klebsiella pneumoniae (98.6% and 95.6% of isolates susceptible). Carbapenems had excellent activity (> or =99.5% of all isolates). ESBL-production was confirmed with the ESBL-Etest and disk diffusion test in 1.3% of Escherichia coli isolates, 18.4% of Klebsiella pneumoniae, 12.6% of Klebsiella oxytoca and 5.3% of Proteus mirabilis isolates.

Aztreonam↗
PubMed1999

Streptococcus pyogenes isolated in Portugal: macrolide resistance phenotypes and correlation with T types. Portuguese Surveillance Group for the Study of Respiratory Pathogens.

From January 1998 to June 1999, 302 clinical isolates of Streptococcus pyogenes were collected from 10 microbiology laboratories in Portugal. All strains were highly sensitive to penicillin (MIC90 = 0.012 mg/liter). The prevalence of erythromycin resistance was 35.8% and of tetracycline resistance 41.4%. The majority (79.6 %) of erythromycin-resistant strains were of the MLSB constitutive resistance (CR) phenotype with high-level resistance to erythromycin (MIC90 >256 mg/liter) and to clindamycin (MIC90 >256 mg/liter), 16.7% showed the M phenotype with low-level erythromycin-resistance (MIC90 = 24 mg/liter) and susceptibility to clindamycin, and four isolates showed a phenotype characterized by low-level erythromycin resistance (MIC90 = 8 mg/liter) and high-level clindamycin resistance (MIC90 >256 mg/liter), not previously described. Erythromycin resistance was not associated with invasive strains. Only minor discrepancies between disk diffusion and E-test methods were observed. T serotyping was very useful for the epidemiological characterization of the strains. The most prevalent T types were T1, T4, T9, T12, T13, and T28. A statistically significant association with resistance patterns was found: T12 with erythromycin resistance MLS(B) CR phenotype (p< 0.001), T4 with erythromycin resistance M phenotype (p<0.001), and T13 with tetracycline resistance (p<0.01). Because of the high prevalence of resistance, careful surveillance of S. pyogenes isolates in Portugal is essential, routine antimicrobial susceptibility testing in clinical microbiology laboratories should be strongly encouraged, antibiotic prescription should be reviewed, and macrolides should no longer be used in the empirical therapy of acute pharyngitis.

Anti-Bacterial Agents↗
PubMed2000

Susceptibility of Polish clinical strains of Yersinia enterocolitica serotype O3 to antibiotics.

A total of 199 clinical strains of Yersinia enterocolitica serotype O3, biotype 4 were tested for their susceptibility to antibiotics (158 strains carried the virulence plasmid pYV and 41 strains did not). A total of 114 isolates were tested by a standard disk diffusion method for 21 antibiotics. Almost all strains tested were resistant to ampicillin and cefazolin and susceptible to amoxycillin/clavulanate, cefaclor, cefamandole, cefuroxime, cefotaxime, ceftriaxone, aztreonam, imipenem, gentamicin, amikacin, netilmicin, tetracycline, doxycycline, chloramphenicol, ciprofloxacin, sulphamethoxazole, trimethoprim, co-trimoxazole and furazolidone. In addition, minimal inhibitory concentrations of 15 antibiotics were determined by the agar dilution method for all 199 strains (158 carrying plasmid pYV and 41 strains that did not). Third-generation cephalosporins such as cefotaxime and ceftriaxone and a fluoroquinolone (ciprofloxacin) were the most active antimicrobial agents tested followed by aztreonam, imipenem, trimethoprim, tetracycline, gentamicin, chloramphenicol, amoxycillin/clavulanate, cefaclor, cefuroxime, amikacin, furazolidone and sulphamethoxazole. The present study demonstrated a high susceptibility of clinical strains of Y. enterocolitica to most of the tested antibiotics. In general there was no significant difference between susceptibility to antibacterial agents of strains with or without plasmid pYV.

Drug Resistance, Microbial↗
PubMed2005

A clinical and microbiological comparison of Staphylococcus aureus toxic shock and scalded skin syndromes in children.

BACKGROUND: This study was designed to compare the clinical characteristics, toxin expression, virulence factors, and antimicrobial susceptibilities of staphylococci isolated from Taiwanese children with staphylococcal toxic shock syndrome (STSS) and staphylococcal scalded skin syndrome (SSSS). METHODS: Demographic characteristics, hospital course, and outcomes of the children were analyzed. Toxin-specific and virulence genes of the staphylococci were detected by polymerase chain reaction amplification. Antimicrobial susceptibilities were determined by disk diffusion and the Etest. RESULTS: Staphylococcus aureus was isolated from 16 children (6 in the STSS group and 10 in the SSSS group). Children with STSS tended to be older than those with SSSS, had a longer duration of hospitalization, and a much higher mortality rate. Community-associated methicillin-resistant S. aureus was isolated from 11 (68.8%) of 16 children. All of these isolates contained the ermB and mecA genes, but none had the mefA gene. All 16 isolates tested positive for the fnbA gene. The pvl and seb genes were more frequently found among S. aureus from the STSS group, compared with S. aureus from the SSSS group. We found that 67% (4 of 6) of the STSS isolates were genetically related. All of the S. aureus isolates were susceptible to vancomycin, gentamicin, doxycycline, and trimethoprim-sulfamethoxazole. Most isolates were resistant to clindamycin (63%), oxacillin (69%), and clarithromycin (81%). CONCLUSIONS: The most distinguishing feature of these isolates is the greater frequency of pvl and seb carriage among those from the STSS group. Most of the isolates were community-associated methicillin-resistant S. aureus that were highly resistant to macrolides but susceptible to trimethoprim-sulfamethoxazole. Vancomycin remains the initial drug of choice for treatment of STSS and SSSS. More studies are needed to determine the efficacy of trimethoprim-sulfamethoxazole in children with these syndromes.

Adolescent↗
PubMed1982

Agar (disk) diffusion test susceptibility of clinical isolates of Pseudomonas aeruginosa to azlocillin, cefotaxime, cefsulodin, lamoxactam, mezlocillin, and piperacillin.

The standardized Bauer-Kirby agar diffusion test served to examine 100 clinical isolates of Pseudomonas aeruginosa against various recently introduced broad-spectrum penicillins and cephalosporins. Neither cefotaxime nor lamoxactam displayed significant activity against this microorganism. Azlocillin, cefsulodin, and piperacillin were significantly more effective (p less than 0.0001) than mezlocillin against the majority of isolates. When compared individually, azlocillin and piperacillin displayed comparable in vitro activity; the same was true for cefsulodin compared with piperacillin. On the other hand, cefsulodin was somewhat more active than azlocillin (p less than 0.05, greater than 0.01) against P. aeruginosa. These data should enable diagnostic laboratories to curtail the number of antimicrobial drugs routinely utilized to examine clinical isolates of P. aeruginosa for antibiotic susceptibility, i.e., piperacillin exclusively.

Azlocillin↗