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Antibiotic Sensitivity (antibiotic + sensitivity)
Selected AbstractsIncidence, spectrum and antibiotic sensitivity pattern of bacterial infections among patients with acute pancreatitisJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2001Pramod Kumar Garg Abstract Background and Aim: Secondary infection of pancreatic necrotic tissue and peripancreatic fluid is a serious complication of acute pancreatitis resulting in significant morbidity and mortality. The aim of this study was to find out the spectrum of bacterial infections, and their antibiotic sensitivity pattern in patients with acute pancreatitis. Methods: All consecutive patients with acute pancreatitis were studied prospectively. Detailed investigations were carried out to identify bacterial infections and their antibiotic sensitivities in patients with suspected infection. These investigations included cultures of various body fluids, throat swabs, indwelling cannula and catheter tips. Pancreatic tissue was obtained by using needle aspiration or at surgery for Gram's stain, culture and sensitivity. All cultures were repeated until the presence of infection was confirmed or excluded. Results: A total of 169 patients with acute pancreatitis were studied during the period between January 1997 and June 2000 (mean age 41.3 years; 116 males and 53 females). Of the 169 patients, 63 had infections at various sites. A total of 80 cultures were positive, and 12 different bacterial isolates were cultured from samples taken from these 63 patients. Polymicrobial infection was seen in 32% of patients. Twenty-four patients had a confirmed pancreatic infection. Blood cultures had a growth of organisms in 19 patients, with evidence of ongoing or worsening pancreatitis, thus raising a strong suspicion of infected necrosis in them. The commonest organisms were Escherichia coli from 20 cultures and Pseudomonas aeruginosa from 18 cultures. The antibiotic sensitivity pattern showed that most bacteria were sensitive to third generation cephalosporins and quinolones; notably among them were cefotaxime, ceftazidime, and ciprofloxacin. Conclusion: Bacterial infections were seen in 37% of patients with acute pancreatitis. The commonest organisms were Pseudomonas aeruginosa and Escherichia coli. Most bacterial isolates were sensitive to third generation cephalosporins and quinolones. [source] Intracellular Staphylococcus aureus and antibiotic resistance: Implications for treatment of staphylococcal osteomyelitisJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2006J. Kent Ellington Abstract Staphylococcus aureus is responsible for 80% of human osteomyelitis. It can invade and persist within osteoblasts. Antibiotic resistant strains of S. aureus make successful treatment of osteomyelitis difficult. Null Hypothesis: antibiotic sensitivities of S. aureus do not change after exposure to the osteoblast intracellular environment. Human and mouse osteoblast cultures were infected and S. aureus cells were allowed to invade. Following times 0, 12, 24, and 48 h (,± the addition of erythromycin, clindamycin, and rifampin at times 0 or 12 h), the osteoblasts were lysed and intracellular bacteria enumerated. Transmission electron microscopy was performed on extracellular and intracellular S. aureus cells. In mouse osteoblasts, administration of bacteriostatic antibiotics at time 0 prevented the increase in intracellular S. aureus. If the antibiotics were delayed 12 h, this did not occur. When rifampin (bactericidal) was introduced at time 0 to human and mouse osteoblasts, there was a significant decrease in number of intracellular S. aureus within osteoblasts compared to control. If rifampin was delayed 12 h, this did not occur. Significant time-dependent S. aureus structural changes were observed after exposure to the osteoblast intracellular environment. These studies demonstrate that once S. aureus is established intracellularly for 12 h, the bacteria are less sensitive to antibiotics capable of eukaryotic cell penetration (statistically significant). These antibiotic sensitivity changes could be due in part to the observed structural changes. This leads to the rejection of our null hypotheses that the antibiotic sensitivities of S. aureus are unaltered by their location. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source] High levels of fusidic acid-resistant Staphylococcus aureus despite restrictions on antibiotic useCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 2 2009A. Mitra Summary Background., High rates of fusidic acid (FA)-resistant Staphylococcus aureus (FRSA) in patients with skin disease have been previously attributed to high usage of topical FA. Aims., To assess whether local community guidelines to restrict topical FA has affected its prescription and use and the level of FRSA in patients with skin disease. Methods.,Stapylococcus aureus isolates from microbiology samples received over a 4-month period in 2004 were tested for antibiotic sensitivities. Comparison was then made with the results of a previous study carried out in 2001. Results., A significant fall was seen in the use of topical FA in dermatology patients. In 2001, 62% of patients had used FA-containing preparations within the previous 6 months, compared with just 15% of patients in 2004 (P < 0.001). The number of topical FA prescriptions in primary and secondary care dropped between 2001 and 2004. The proportion of S. aureus isolates resistant to FA in dermatology patients had not significantly fallen between 2001 (50%) and 2004 (41%) (P = 0.4). However, there was a significant increase in FA resistance within hospital inpatients, nondermatology outpatients and primary-care patients (P < 0.05). The FRSA level had doubled in hospital inpatients (20%) and almost tripled in nondermatology outpatients (28%) and primary care patients (25%). Conclusion., Persistent high levels of FA resistance may represent the development of an FRSA reservoir in the community. Continued restriction of FA is still recommended. [source] Characterization of potential stress responses in ancient Siberian permafrost psychroactive bacteriaFEMS MICROBIOLOGY ECOLOGY, Issue 1 2005Monica A. Ponder Abstract Past studies of cold-acclimated bacteria have focused primarily on organisms not capable of sub-zero growth. Siberian permafrost isolates Exiguobacterium sp. 255-15 and Psychrobacter sp. 273-4, which grow at subzero temperatures, were used to study cold-acclimated physiology. Changes in membrane composition and exopolysaccharides were defined as a function of growth at 24, 4 and ,2.5 °C in the presence and absence of 5% NaCl. As expected, there was a decrease in fatty acid saturation and chain length at the colder temperatures and a further decrease in the degree of saturation at higher osmolarity. A shift in carbon source utilization and antibiotic resistance occurred at 4 versus 24 °C growth, perhaps due to changes in the membrane transport. Some carbon substrates were used uniquely at 4 °C and, in general, increased antibiotic sensitivity was observed at 4 °C. All the permafrost strains tested were resistant to long-term freezing (1 year) and were not particularly unique in their UVC tolerance. Most of the tested isolates had moderate ice nucleation activity, and particularly interesting was the fact that the Gram-positive Exiguobacterium showed some soluble ice nucleation activity. In general the features measured suggest that the Siberian organisms have adapted to the conditions of long-term freezing at least for the temperatures of the Kolyma region which are ,10 to ,12 °C where intracellular water is likely not frozen. [source] AcrA suppressor alterations reverse the drug hypersensitivity phenotype of a TolC mutant by inducing TolC aperture openingMOLECULAR MICROBIOLOGY, Issue 6 2010Jon W. Weeks Summary In Escherichia coli, the TolC,AcrAB complex forms a major antibiotic efflux system with broad substrate specificity. During the complex assembly, the periplasmic helices and bottom turns of TolC are thought to interact with a hairpin helix of AcrA and hairpin loops of AcrB respectively. In the present study we show that a four-residue substitution in TolC's turn 1, which connects outer helices 3 and 4 proximal to TolC's periplasmic aperture, confers antibiotic hypersensitivity, without affecting TolC-mediated phage or colicin infection. However, despite the null-like drug sensitivity phenotype, chemical cross-linking analysis revealed no apparent defects in the ability of the mutant TolC protein to physically interact with AcrA and AcrB. A role for TolC turn 1 residues in the functional assembly of the tripartite efflux pump complex was uncovered through isolating suppressor mutations of the mutant TolC protein that mapped within acrA and by utilizing a labile AcrA protein. The data showed that AcrA-mediated suppression of antibiotic sensitivity was achieved by dilating the TolC aperture/channel in an AcrB-dependent manner. The results underscore the importance of the periplasmic turn 1 of TolC in the functional assembly of the tripartite efflux complex and AcrA in transitioning TolC from its closed to open state. [source] Have the Organisms that Cause Breast Abscess Changed With Time?,,Implications for Appropriate Antibiotic Usage in Primary and Secondary CareTHE BREAST JOURNAL, Issue 4 2010Natalie Dabbas MBBS Abstract:, Many patients with breast abscess are managed in primary care. Knowledge of current trends in the bacteriology is valuable in informing antibiotic choices. This study reviews bacterial cultures of a large series of breast abscesses to determine whether there has been a change in the causative organisms during the era of increasing methicillin-resistant Staphylococcus aureus (MRSA). Analysis was undertaken of all breast abscesses treated in a single unit over 2003 , 2006, including abscess type, bacterial culture, antibiotic sensitivity and resistance patterns. One hundred and ninety cultures were obtained (32.8% lactational abscess, 67.2% nonlactational). 83% yielded organisms. Staphylococcus aureus was the commonest organism isolated (51.3%). Of these, 8.6% were MRSA. Other common organisms included mixed anaerobes (13.7%), and anaerobic cocci (6.3%). Lactational abscesses were significantly more likely to be caused by S. aureus (p < 0.05). Methicillin-resistant Staphylococcus aureus rates were not statistically different between lactational and nonlactational abscess groups. Appropriate antibiotic choices are of great importance in the community management of breast abscess. Ideally, microbial cultures should be obtained to institute targeted therapy but we recommend the continued use of flucloxacillin with or without metronidazole (or amoxicillin-clavulanate as a single preparation) as initial empirical therapy. [source] Bacteriologic Comparison of Tonsil Core in Recurrent Tonsillitis and Tonsillar Hypertrophy,THE LARYNGOSCOPE, Issue 12 2007Jin Hyeok Jeong MD Abstract Objectives: Although many bacteriology studies on tonsillar diseases have been completed, all have been confined to children and were characterized by a paucity of cases. The purpose of this study was to analyze the underlying bacterial pathogens in tonsillar disease. Methods: A retrospective study was performed on 824 patients who underwent elective tonsillectomy with or without adenoidectomy. We analyzed the differences between the bacterial pathogens in recurrent tonsillitis and tonsillar hypertrophy with regard to age, season, and antibiotic sensitivity. Results: Among 824 cases, 966 bacterial strains from the tonsil core were isolated. In recurrent tonsillitis, Staphylococcus aureus was the most common pathogen (30.3%), followed by Haemophilus influenzae (15.5%) and group A ,-hemolytic Streptococcus (Streptococcus pyogenes, 14.4%). In patients over 14 years of age, quite differently from other age groups, Klebsiella pneumoniae was isolated at a significantly higher percentage. In tonsillar hypertrophy, H. influenzae was isolated most commonly (31.4%) regardless of age, followed by S. pyogenes (24.2%), S. aureus (22.9%), and Streptococcus pneumoniae (12.6%). Furthermore, mixed infection was common because of its high resistance to penicillin. In both groups, S. pneumoniae was more common in younger patients, whereas K. pneumoniae was relatively common in adults. We found no differences in the detection rate by season; however, H. influenzae was frequently isolated in the tonsillar hypertrophy group regardless of seasonal variations. We also found no difference in the antibiotic sensitivity between the two groups; however, strains resistant to penicillin were relatively prevalent and showed a high sensitivity to third-generation cephalosporin. Conclusions: We observed some differences in the types of bacteria in the tonsillar core between the recurrent tonsillitis and tonsillar hypertrophy groups. Our study indicates that essential bacteria have been changing and, thus, we need to change our choice of antibiotics. [source] Characterisation of isolates of Staphylococcus aureus from acute, chronic and subclinical mastitis in cows in NorwayAPMIS, Issue 9 2000TORE Tollersrud Eighty-six Staphylococcus aureus isolates from cases of bovine mastitis were characterised biochemically and with respect to serotype, multilocus enzyme electrophoresis genotypes, antibiotic sensitivity, and production of enterotoxins A through D (SEA-D) and toxic shock syndrome toxin-1 (TSST-1). The samples were obtained from 81 different cows from 79 Norwegian dairy herds in 10 different counties in southern Norway. There was an equal representation of isolates from cases of acute, chronic and subclinical mastitis. Multilocus enzyme electrophoresis using 13 genetic loci showed that 69 of 86 isolates had the same electrophoretic type. This common electrophoretic type comprised isolates that differed in the expression of other phenotypical characteristics studied. Fifty-eight percent of the isolates produced one or more enterotoxins, predominantly a combination of SEC and TSST-1. Capsular serotyping revealed that 95% of the isolates belonged to serotype 8. No correlation was found between the factors studied and the clinical classification of mastitis. It appears that the majority of S. aureus isolates recovered from cases of bovine mastitis in Norway are genetically closely related and express common phenotypical characteristics. [source] | |||||||||||||