Molecular and Clinical Features of Heterogeneous Vancomycin Intermediate Staphylococcus aureus in Tertiary Care Hospitals of South India

Objectives: This study aimed to detect heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) among methicillin resistant S. aureus (MRSA) isolated from healthcare-associated infections and identify staphylococcal cassette chromosome mec (SCCmec) types. Methods: Isolation and identification of MRSA were done using standard bacteriological methods. Antimicrobial susceptibility testing was done using Kirby-Bauer disc diffusion and macrolide-lincosamide-streptogramin B (MLSB) phenotypes identified using D test. The minimum inhibitory concentration (MIC) of vancomycin was determined using agar dilution. hVISA were confirmed by modified population analysis profile-area under the curve (PAP-AUC) test. SCCmec types and Panton-Valentine leukocidin (pvl) were detected using multiplex PCR. Results: Out of 220 MRSA stains, 14 (6.4%) were hVISA. None of the MRSA isolate was vancomycin intermediate or resistant. All hVISA were susceptible to linezolid and teicoplanin. Macrolide-streptogramin B (MSB) phenotype was present in 42.9% hVISA. 92.9% hVISA strains had vancomycin MIC in the range 1-2 µg/mL. Majority of hVISA and vancomycin susceptible MRSA were isolated from skin and soft tissue infections. SCCmec III and IV were present in 50% and 35.7% hVISA respectively. 14.3% hVISA harboured SCCmec V. Conclusion: The rate of hVISA among MRSA was 6.4%. MRSA strains should be tested for hVISA before starting vancomycin treatment. None of the isolates was vancomycin intermediate or resistant. All the hVISA strains were susceptible to linezolid and teicoplanin. The majority of hVISA were isolated from skin and soft tissue infections. The majority hVISA harboured SCCmec III and IV. Keywords: MRSA; Hospital infection; Molecular typing; Vancomyci

Healthcare-Associated Methicillin-Resistant Staphylococcus aureus : Clinical characteristics and antibiotic resistance profile with emphasis on macrolide-lincosamide...

Objectives: Healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen worldwide and its multidrug resistance is a major concern. This study aimed to determine the clinical characteristics and antibiotic susceptibility profile of healthcare-associated MRSA with emphasis on resistance to macrolide-lincosamide-streptogramin B (MLSB) phenotypes and vancomycin. Methods: This cross-sectional study was carried out between February 2014 and February 2015 across four tertiary care hospitals in Mangalore, South India. Healthcare-associated infections among 291 inpatients at these hospitals were identified according to the Centers for Disease Control and Prevention guidelines. Clinical specimens were collected based on infection type. S. aureus and MRSA isolates were identified and antibiotic susceptibility tests performed using the Kirby-Bauer disk diffusion method. The minimum inhibitory concentration of vancomycin was determined using the Agar dilution method and inducible clindamycin resistance was detected with a double-disk diffusion test (D-test). Results: Out of 291 healthcare-associated S. aureus cases, 88 were MRSA (30.2%). Of these, 54.6% were skin and soft tissue infections. All of the isolates were susceptible to teicoplanin and linezolid. Four MRSA isolates exhibited intermediate resistance to vancomycin (4.6%). Of the MRSA strains, 10 (11.4%) were constitutive MLSB phenotypes, 31 (35.2%) were inducible MLSBphenotypes and 14 (15.9%) were macrolide-streptogramin B phenotypes. Conclusion: Healthcare-associated MRSA multidrug resistance was alarmingly high. In routine antibiotic susceptibility testing, a D-test should always be performed if an isolate is resistant to erythromycin but susceptible to clindamycin. Determination of the minimum inhibitory concentration of vancomycin is necessary when treating patients with MRSA infections

COMPARISON OF ETEST AND AGAR DILUTION FOR DETERMINING MINIMUM INHIBITORY CONCENTRATION OF VANCOMYCIN TO HEALTHCARE-ASSOCIATED METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS

ABSTRACTObjectives: To compare agar dilution method and Etest in the determination of minimum inhibitory concentration (MIC) of vancomycin to healthcareassociatedmethicillin-resistantStaphylococcusaureus(HA-MRSA).Methods: A total of 98 non-duplicate strains of HA-MRSA isolated from different clinical specimens were tested for their antibiotic susceptibilitypattern by Kirby-Bauer disk diffusion method and vancomycin MIC by agar dilution method and Etest (BioMerieux, France).Results: Out of 98 strains of HA-MRSA, 94 (95.9%) were vancomycin susceptible (MIC ≤2 µg/ml and 4 (4.1%) were vancomycin intermediate (MIC4 µg/ml) by agar dilution method. By Etest, 53 (54.1%) were vancomycin susceptible, 4 (4.1%) were vancomycin intermediate, and the remaining 41isolates had vancomycin MIC between 2 µg/ml and 4 µg/ml.Conclusion: Etest allows the detection of HA-MRSA strains with intermediate MIC values in addition to traditional dilutions. These properties willhelp in detection of MIC creep and also decision-making in using vancomycin for the treatment of serious infections caused by HA-MRSA.Keyword: Vancomycin, Minimum inhibitory concentration, Etest, Agar dilution

IN VITRO ACTIVITY OF VANCOMYCIN AND DAPTOMYCIN AGAINST HEALTHCARE-ASSOCIATED METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS ISOLATED FROM CLINICAL SPECIMENS

ABSTRACTObjective: The present cross-sectional study was conducted to determine minimum inhibitory concentration (MIC) of daptomycin and vancomycinto clinical isolates of healthcare-associated-methicillin-resistant Staphylococcus aureus (HA-MRSA).Methods: Centers for Disease Control and Prevention Criteria were used to define HR infections due to MRSA. Antibiotic susceptibility testing wasdone by Kirby–Bauer disk diffusion method. MIC of vancomycin and daptomycin was determined by Agar dilution method and E-test, respectively.Results of antibiotic susceptibility testing and MIC were interpreted as per Clinical Laboratory Standard Institute guidelines.Results: A total of 110 strains of MRSA were isolated from healthcare-associated infections. All were susceptible to daptomycin, linezolid, andteicoplanin. A total of 106 isolates were vancomycin susceptible and four were vancomycin-intermediate S. aureus (VISA). MIC ofvancomycin were 2 µg/ml. All MRSA isolates were susceptible to daptomycin. Four VISA strains had daptomycin MIC 1 µg/ml.Conclusion: The present study showed the emergence of VISA among HA-MRSA isolates with high MIC for vancomycin. Although all HA-MRSAisolates were susceptible to daptomycin, VISA isolates had high daptomycin MIC. This indicates that daptomycin may not be used as an alternativechoice for VISA infections.Keywords: Healthcare-associated methicillin-resistant Staphylococcus aureus, Vancomycin, Daptomycin.9090and MIC5

VANCOMYCIN INTERMEDIATE AND VANCOMYCIN RESISTANT STAPHYLOCOCCUS AUREUS – MECHANISMS, CLINICAL SIGNIFICANCE AND DETECTION

Vancomycin is used as the antibiotic of choice for severe infection caused by methicillin resistant Staphylococcus aureus. Increased use of vancomycin and the selective pressure has resulted in the emergence of S.aureus with reduced susceptibility to vancomycin and vancomycin resistant S.aureus. This review summarizes the definition, mechanism, clinical significance and epidemiology of S.aureus with reduced susceptibility to vancomycin. It also discusses laboratory methods for detection and treatment options available for these pathogens

Characterization of virulence factors and antibiotic resistance pattern of uropathogenic Escherichia coli strains in a tertiary care center [version 2; peer review: 2 approved]

Background: Urinary tract infection(UTI) is one of the commonly prevalent bacterial infection in humans.The uropathogenic E. coli (UPEC) expresses a range of virulence factors that contribute to their pathogenicity. The emergence of multidrug resistance (MDR)-associated UTI is increasing.This study monitors the distribution of virulence factors among UPEC strains to note the antibiogram, outcome and type of associated UTI. Methods:A prospective cross-sectional time-bound study of six months was done on clinically significant urinary isolates of Escherichia coli. Detection of haemolysin production and serum resistance was done by phenotypic methods. Genotypic characterization of the virulence genes (papC, iutA, hlyA, cnf1) was done by multiplex PCR. Demographic data, clinical history, antibiogram and type of UTI was collected from clinical case records. Results:75 E.coli isolates from patients with suspected UTIs were included. Females had a higher preponderance of UTI (66.7%). 93% of patients were adults and the remaining 7% were from paediatrics.  24 (32%) isolates showed haemolysis by plate haemolysis and all isolates were serum-resistant. Out of 75 isolates, 65 were positive for at least one of four targeted genes, while remaining ten isolates were negative for all four genes.Multidrug resistance was found in 40 (53.3%) isolates. 97.4% of the UTI cases had a favourable clinical outcome at discharge. Mortality due to urosepsis was 2.6%. Conclusion:Association of hemolysin production with resistance to imipenem and norfloxacin in UPEC strains was significant.Presence of hlyA gene is positively associated with ceftazidime resistance. Nitrofurantoin, piperacillin, tazobactam, and cefaperazone sulbactam are possible candidates for empirical therapy of UTIs. Drugs like aminoglycosides, carbapenems and fosfomycin may be used as reserve drugs in the treatment of MDR-UTI.However, inappropriate usage can increase antibiotic resistance. Hence proper selection of antibiotics in hospitals taking into account the local antibiogram is needed to reduce the emergence of antibiotic resistance

Hematopoietic Cell Transplantation in Patients With Primary Immune Regulatory Disorders (PIRD): A Primary Immune Deficiency Treatment Consortium (PIDTC) Survey.

Primary Immune Regulatory Disorders (PIRD) are an expanding group of diseases caused by gene defects in several different immune pathways, such as regulatory T cell function. Patients with PIRD develop clinical manifestations associated with diminished and exaggerated immune responses. Management of these patients is complicated; oftentimes immunosuppressive therapies are insufficient, and patients may require hematopoietic cell transplant (HCT) for treatment. Analysis of HCT data in PIRD patients have previously focused on a single gene defect. This study surveyed transplanted patients with a phenotypic clinical picture consistent with PIRD treated in 33 Primary Immune Deficiency Treatment Consortium centers and European centers. Our data showed that PIRD patients often had immunodeficient and autoimmune features affecting multiple organ systems. Transplantation resulted in resolution of disease manifestations in more than half of the patients with an overall 5-years survival of 67%. This study, the first to encompass disorders across the PIRD spectrum, highlights the need for further research in PIRD management

<span style="font-size:14.0pt;font-family:"Times New Roman";color:#141414;mso-bidi-font-weight: bold" lang="EN-IN">Synthesis and antibacterial activities of some fluorine containing <span style="font-size:14.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";color:#141414;mso-ansi-language:EN-IN; mso-fareast-language:EN-IN;mso-bidi-language:HI;mso-bidi-font-weight:bold" lang="EN-IN">arylfurylpropenones, pyrazolines and <i>N- </i>acetylpyrazoline</span></span>

440-447Several fluorine containing arylfurylpropenones 3 have been synthesized starting from arylfurfurals 1 and 2,4-dichloro-5- fluoroacetophenone 2. These arylfurylpropenones are then used for the synthesis of fluorine containing arylfurylpyrazolines 4.The newly synthesized pyrazolines are then converted into their N-acetyl derivatives 5. The structures of these compounds have been confirmed on the basis of elemental analysis, IR, NMR and mass spectral studies. The mechanism for the formation of pyrazolines has been investigated. The above compounds are also subjected to antibacterial screening. Their minimal inhibitory concentration <span style="font-size:14.0pt;line-height:115%;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";color:#393939;="" mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">(MIC) values indicate that some of these compounds exhibit <span style="font-size:14.0pt;line-height:115%; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:#393939;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">exce<span style="font-size:14.0pt;line-height:115%; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:#141414;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">ll<span style="font-size:14.0pt;line-height:115%; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:#393939;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">ent <span style="font-size:14.0pt;line-height:115%; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:#262626;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">antibacterial <span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:#393939;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">ac<span style="font-size:14.0pt;line-height:115%; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:#141414;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">tivities

Studies on arylfuran derivatives: Part IX-Synthesis and characterization of some fluorine containing arylfurylvinylquinazolinones as possible antibacterial agents

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