Home About us Contact
|
Home About us Contact | ||
|
|
||
Susceptibility Patterns (susceptibility + pattern)
Selected AbstractsComparison of Salmonella enterica serotype Infantis isolates from a veterinary teaching hospitalJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2007M. Dunowska Abstract Aims:, To compare Salmonella enterica serotype Infantis isolates obtained from patients or the environment of a veterinary teaching hospital over a period of 9 years following a nosocomial outbreak to determine whether isolates were epidemiologically related or represented unrelated introductions into the hospital environment. Methods and Results:, Fifty-six S. Infantis isolates were compared based on their phenotypic (antimicrobial drug [AMD] susceptibility pattern) and genotypic (pulsed-field gel electrophoresis [PFGE] pattern and presence of integrons) characteristics. Epidemiologically unrelated S. Infantis isolates clustered separately from all but two of the hospital isolates, and several isolates from different years and various sources were indistinguishable from each other in cluster analysis of two-enzyme PFGE results. A high percentage of isolates (80·3%) were resistant to at least one AMD, with 67·8% showing resistance to >5 AMD. The majority (74·1%) of isolates tested contained type 1 integrons. Conclusion:, Results strongly suggest that there was nosocomial transmission of S. Infantis during the initial outbreak, and that contamination arising from this outbreak persisted across years despite rigorous hygiene and biosecurity precautions and may have led to subsequent nosocomial infections. Significance and Impact of the Study:, Evidence of persistence and transmission of Salmonella clones across years, even in the face of rigorous preventive measures, has important implications for other facilities that have experienced outbreaks of Salmonella infections. [source] The use of ribotyping and antibiotic resistance patterns for identification of host sources of Escherichia coli strainsLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2005M. Samadpour Abstract Aims:, To compare antibiotic resistance and ribotyping patterns ability to identify triplicate isolates sent from a group of 40 Escherichia coli taken from seven host sources. Methods and Results:, Of the 120 isolates, 22 isolates were resistant to ampicillin, streptomycin, tetracycline and trimethoprim and 98 isolates were susceptible. Antibiotic patterns identified 33 of the triplicates and three of the six groups had isolates from multiple hosts. Ribotyping divided the isolates into 27 ribotype groups with all triplicates grouped into the same ribotype group with one host per group. Conclusions:, Antibiotic susceptibility pattern placed 98 of the isolates in a single group with 50% of the antibiotic susceptibility pattern groups containing multiple host species. Ribotyping groups were host specific with each host having one to seven ribotype groups. Significance and Impact of the Study:, Antibiotic susceptibility pattern groups have been used for environmental source identification and faecal pollution tracking, however these groups do not always distinguish between host species. Stability of the markers is a potential concern and this system can only be used if antibiotic resistance levels are high in the isolates studied. All isolates have a ribotype group which was stable and like other molecular methods has advantages over antibiotic susceptibility pattern groups which uses a phenotypic method. [source] Viridans group streptococci: a reservoir of resistant bacteria in oral cavitiesCLINICAL MICROBIOLOGY AND INFECTION, Issue 2 2002A. Bryskier The worldwide spread of erythromycin A-resistant streptococci, including Streptococcus pneumoniae, is of concern. Many studies have demonstrated that the viridans group streptococci can be a reservoir of erythromycin A resistance. Within oral streptoccoci, an important difference in the susceptibility pattern has been noted. The purpose of this short editorial is to highlight the importance of this group of bacteria as a reservoir of resistance to erythromycin A and the possible transfer of resistance to S. pneumoniae and S. pyogenes. [source] Resistant Pathogens in Urinary Tract InfectionsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2002Lindsay E. Nicolle MD Antimicrobial susceptibility of bacteria causing urinary tract infection (UTI) has evolved over several decades as antimicrobial exposure has repeatedly been followed by emergence of resistance. Older populations in the community, long-term care facilities, or acute care facilities have an increased prevalence of resistant bacteria isolated from UTI. Resistant isolates are more frequent in long-term care populations than the community. Resistant isolates include common uropathogens, such as Escherichia coli or Proteus mirabilis, and organisms with higher levels of intrinsic resistance, such as Pseudomonas aeruginosa or Providencia stuartii. Isolation of resistant organisms is consistently associated with prior antimicrobial exposure and higher functional impairment. The increased likelihood of resistant bacteria makes it essential that a urine specimen for culture and susceptibility testing be obtained before instituting antimicrobial therapy. Therapy for the individual patient must be balanced with the possibility that antimicrobial use will promote further resistance. Antimicrobial therapy should be avoided unless there is a clear clinical indication. In particular, asymptomatic bacteriuria should not be treated with antimicrobials. Where symptoms are mild or equivocal, urine culture results should be obtained before initiating therapy. This permits selection of specific therapy for the infecting organism and avoids empiric, usually broad-spectrum, therapy. Where empirical therapy is necessary, prior infecting organisms should be isolated, and recent antimicrobial therapy, as well as regional or facility susceptibility patterns, should be considered in antimicrobial choice. Where empirical therapy is used, it should be reassessed 48 to 72 hours after initiation, once pretherapy cultures are available. [source] Phenotypes, serotypes and antibiotic susceptibility of Swedish Porphyromonas gingivalis isolates from periodontitis and periodontal abscessesMOLECULAR ORAL MICROBIOLOGY, Issue 2 2007G. Dahlén This study was conducted to reveal phenotypic, serological subtypes and antibiotic susceptibility among fresh isolates of Porphyromonas gingivalis in a Swedish population with periodontitis and periodontal abscess. Fifty-five subgingival strains were isolated and tentatively designated as P. gingivalis from 55 consecutive paper-point samples taken from 51 patients with periodontitis (at least one site with >6-mm pocket depth) in Sweden and were sent in for microbiological evaluation. Eight P. gingivalis strains from periodontal abscesses were also included. Four P. gingivalis strains served as reference and another four type strains were included. The strains were characterized by colony morphology, biochemical tests, enzyme profile, gas,liquid chromatography and antibiotic susceptibility. The strains were further characterized for whole cell protein profiles using sodium dodecyl sulphate,polyacrylamide gel electrophoresis (SDS,PAGE) and were identified to serotype by specific monoclonal antibodies. Among the 55 P. gingivalis strains 35 had smooth (S), 13 rough (R) and seven semi-rough colony morphologies. All strains were phenotypically homogeneous in biochemical tests, enzyme profile and antibiotic susceptibility. All strains produced phenylacetic acid and , -fucosidase. Almost all (96%) of the subgingival strains, but relatively fewer (62%) of the abscess strains, belonged to serotype A. Two subgingival and three abscess strains were classified as serotype B. No specific SDS,PAGE protein profiles were recorded for the two serotypes. The P. gingivalis strains from Swedish periodontitis cases showed homogeneity in terms of biochemical phenotypes and antibiotic susceptibility patterns. The strains fell into two serotypes, of which serotype A predominated in the periodontitis cases and serotype B was overrepresented in periodontal abscesses. [source] Sample survey of drug-resistant tuberculosis in Henan, China, 1996RESPIROLOGY, Issue 1 2002GUOBIN WANG Background: There is little reliable data on the global drug resistance to tuberculosis (TB) as most of the existing data is based upon biased samples, is not standardized or was obtained using poor techniques. For this reason, the World Health Organization (WHO) and the International Union Against Tuberculosis and Lung Disease (IUATLD) developed a global project on anti-TB drug resistance surveillance (DRS) in 1994. China joined this project in 1995 and the province of Henan was selected as the first site for collection of representative samples to survey the prevalence of drug-resistant TB. Methodology: Standard drug susceptibility testing by the proportion method against streptomycin (S), isoniazid (H), rifampicin (R), and ethambutol (E) was performed with Mycobacterium tuberculosis isolated from 916 new cases and 456 previously treated cases. Treatment outcome of these patients has been evaluated according to the regimens and drug susceptibility patterns. Results: Drug resistance among new cases to any drug was found to be 43.0% and any resistance: S, 32.5%; H, 31.0%; R, 20.7%; and E, 10.3%. Drug resistance among previously treated cases to any drug was 68.2% and any resistance: S, 52.2%; H, 49.3%; R, 48.3%; and E, 20.4%. The cure rate for new cases was 43.3% and 29.4% for previously treated cases. The poor cure rate resulted mainly from a high defaulter rate. Conclusion: Drug-resistant TB was found to be highly prevalent in Henan and the cure rate remained poor. The results strongly indicated that Henan should take immediate action to improve the cure rate of patients through expansion of the introduction of the directly observed treatment short-course strategy. [source] Veterinary Drug Usage and Antimicrobial Resistance in Bacteria of Animal OriginBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 4 2005Frank M. Aarestrup There are large variations in the amounts of antimicrobial agents used to produce the same amount of meat among the different European countries, which leaves room for considerable reductions in some countries. The emergence of resistant bacteria and resistance genes due to the use of antimicrobial agents are well documented. In Denmark it has been possible to reduce the usage of antimicrobial agents for food animals significantly and in general decreases in resistance have followed. Guidelines for prudent use of antimicrobial agents may help to slow down the selection for resistance and should be based on knowledge regarding the normal susceptibility patterns of the causative agents and take into account the potential problems for human health. Current knowledge regarding the occurrence of antimicrobial resistance in food animals, the quantitative impact of the use of different antimicrobial agents on selection of resistance and the most appropriate treatment regimes to limit the development of resistance is incomplete. Programmes monitoring the occurrence and development of resistance and consumption of antimicrobial agents are strongly desirable, as is research into the most appropriate ways to use antimicrobial agents in veterinary medicine. [source] In vitro antifungal susceptibility patterns of dermatophyte strains causing tinea unguiumCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 6 2007E. Sarifakioglu Summary Background., Dermatophytes are the major responsible organisms in onychomycosis. Although recent antifungal agents have high success rates in treating this condition, lack of clinical response may occur in 20%. Antifungal drug resistance may be one of the causes of treatment failure. The need for in vitro antifungal drug resistance in daily practice is still under discussion. Objective., We aimed to determine the in vitro susceptibility patterns of dermatophytes causing onychomycosis, against the traditionally available systemic antifungal agents terbinafine, itraconazole and fluconazole. Methods., In total, 100 otherwise healthy patients with suspected onychomycosis were included. Nail clippings were cultured on Sabouraud dexrose agar, mycobiotic agar and dermatophyte test medium. Antifungal susceptibility tests were carried out, mainly following The National Committee for Clinical and Laboratory Standards (M38-P) protocol standard for filamentous fungi. Different concentrations of terbinafine (0.008,8 µg/mL), itraconazole (0.015,16 µg/mL) and fluconazole (0.06,64 µg/mL) were tested. Minimum inhibitory concentration end-point determination was chosen as 100% growth inhibition for terbinafine and 80% for azoles. Results., Of the 100 nail samples, 43% grew dermatophytes. The main causative organism was Trichophyton rubrum (91%) followed by Trichophyton mentagrophytes (9%). Terbinafine had the lowest minimum inhibitory concentration (0.008 µg/mL) followed by itraconazole. Fluconazole showed the greatest variation in minimum inhibitory concentration (0.03,2 µg/mL) and had different susceptibility patterns for the two species. Conclusions., Of the three antifungals tested, terbinafine had the most potent in vitro antifungal activity against dermatophytes. Antifungal susceptibility tests would be useful to screen antifungal-resistant dermatophyte strains. [source] | |||||||||||||