scholarly journals Fluoroquinolone Therapy in Staphylococcus aureus Infections: Where Do We Stand?

2013 ◽  
Vol 5 (02) ◽  
pp. 109-112 ◽  
Author(s):  
Neeta D Gade ◽  
Mohiuddin S Qazi

ABSTRACT Aim: The study aimed to evaluate the utility of various commonly used fluoroquinolones against Staphylococcus aureus isolates. Materials and Methods: A total of 250 isolates of S. aureus were studied from different clinical specimens like blood, pus, wound swabs, sputum, ear swabs, and body fluids between November 2009 and December 2011. All the isolates were tested for their susceptibility to fluoroquinolones and other antimicrobial agents by Kirby-Bauer disc diffusion method using criteria of standard zone of inhibition. Methicillin-resistant S. aureus (MRSA) detection was done by cefoxitin disk diffusion method. The MRSA isolates were tested for minimum inhibitory concentration (MIC) to vancomycin by E-test strips. All the MRSA strains were sent to National Staphylococcal Phage-typing Centre, Maulana Azad Medical College, New Delhi for phage typing. Results: A total of 107 strains of S. aureus (42.8%) were detected as MRSA. Multidrug resistance was observed among the MRSA strains more commonly than among the MSSA stains. Among the fluoroquinolones, maximum resistance in MRSA was seen to ciprofloxacin (92.5%), followed by ofloxacin (80.4%). None of the S. aureus isolates showed resistance to vancomycin and linezolid. The MICs of vancomycin for the MRSA tested ranged from 0.5 to 2 μg/ml. Phage typing pattern of 107 MRSA isolates revealed that 37 (34.6%) MRSA isolates were nontypeable and 70 (65.4%) were typeable. Conclusion: Ciprofloxacin can no longer be used in empirical therapy against MRSA infections. Use of other members of fluoroquinolone should be limited only to those strains that show laboratory confirmation of their susceptibility. Vancomycin remains the drug of choice to treat MRSA infections.

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 439 ◽  
Author(s):  
Vanessa Silva ◽  
Telma de Sousa ◽  
Paula Gómez ◽  
Carolina Sabença ◽  
Madalena Vieira-Pinto ◽  
...  

Methicillin-resistant Staphylococcus aureus (MRSA) are one of the main pathogens associated with purulent infections. MRSA clonal complex 97 (CC97) has been identified in a wide diversity of livestock animals. Therefore, we aimed to investigate the antibiotic resistance profiles of MRSA strains isolated from purulent lesions of food-producing rabbits. Samples from purulent lesions of 66 rabbits were collected in a slaughterhouse in Portugal. Samples were seeded onto ORSAB plates with 2 mg/L of oxacillin for MRSA isolation. Susceptibility to antibiotics was tested by the disk diffusion method against 14 antimicrobial agents. The presence of resistance genes, virulence factors and the immune evasion cluster (IEC) system was studied by polymerase chain reaction. All isolates were characterized by multilocus sequence typing (MLST), agr and spa typing. From the 66 samples analyzed, 16 (24.2%) MRSA were detected. All strains were classified as multidrug-resistant as they were resistant to at least three classes of antibiotics. All isolates showed resistance to penicillin, erythromycin and clindamycin. Seven isolates were resistant to gentamicin and harbored the aac(6′)-Ie-aph (2″)-Ia gene. Resistance to tetracycline was detected in 10 isolates harboring the tet(K) gene. The IEC genes were detected in three isolates. MRSA strains belonged to CC97, CC1, CC5, CC15 or CC22. The isolates were assigned to six different spa types. In this study we found a moderate prevalence of multidrug-resistant MRSA strains in food-producing rabbits. This may represent concern for food safety and public health, since cross-contamination may occur, leading to the spread of MRSA and, eventually, the possibility of ingestion of contaminated meat.


2020 ◽  
pp. 18-20
Author(s):  
Manish Kumar Purbey ◽  
Sanjan Sanju ◽  
R. S. Prasad ◽  
Debarshi Jana

Background Staphylococci are Gram-positive cocci arranged in clusters. They are colonized in humans and animals. Also, Staphylococcus aureus (S. aureus) is frequently associated with various superficial to deep-seated infections in humans. Due to the potential for easy transmission, Staphylococci are associated with both hospital-acquired and community-associated infections. Strains of S. aureus resistant to methicillin (MRSA) pose treatment challenges. In such cases, vancomycin isthe treatment of choice. Due to the indiscriminate use of vancomycin, recently, we are seeing the emergence of vancomycin-intermediate sensitive S. aureus (VISA) and vancomycin-resistant S. aureus (VRSA). The present study aims to evaluate the minimum inhibitory concentrations (MICs) of vancomycin and daptomycin among MRSA strains isolated from human clinical specimens Methods The study included 115 MRSA isolates collected over 24 months from October 2018 to September 2020. The strains were isolated from pus, urine, wound swabs, catheters, blood, and sputum. The bacteria were acquired from different inpatient and outpatient departments of Darbhanga Medical College and Hospital (DMCH), Laheriasrai, Bihar. Kirby-Bauer disk diffusion method using cefoxitin was used to confirm the MRSA isolates. The agar dilution and the Epsilometer method (E-test) were used to test the MICs of MRSA isolates against vancomycin and daptomycin, respectively, by the standard procedures recommended by the clinical laboratory standards institute (CLSI). Results Of the 115 S. aureus isolates, seven (6.08%) strains were resistant to vancomycin (VRSA) and 53 (46.08%) were found to be VISA using the new CLSI breakpoints. The MIC of the daptomycin was found to be ≤1 µg/ml for all the MRSA isolates. Conclusion The study results depicted an increasing trend in the vancomycin MICs among the MRSA isolates. Several tested strains show MICs in the intermediate sensitive range (VISA). The daptomycin was effective against all the MRSA isolates.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Tiago Gomes Fernandes ◽  
Amanda Rafaela Carneiro de Mesquita ◽  
Karina Perrelli Randau ◽  
Adelisa Alves Franchitti ◽  
Eulália Azevedo Ximenes

The aim of this study was to evaluate the antimicrobial activity of aqueous extract ofPsidium guineenseSwartz (Araçá-do-campo) and five antimicrobials (ampicillin, amoxicillin/clavulanic acid, cefoxitin, ciprofloxacin, and meropenem) against twelve strains ofStaphylococcus aureuswith a resistant phenotype previously determined by the disk diffusion method. FourS. aureusstrains showed resistance to all antimicrobial agents tested and were selected for the study of the interaction between aqueous extract ofP. guineenseand antimicrobial agents, by the checkerboard method. The criteria used to evaluate the synergistic activity were defined by the fractional inhibitory concentration index (FICI). AllS. aureusstrains were susceptible toP. guineenseas determined by the microdilution method. The combination of theP. guineenseextract with the antimicrobial agents resulted in an eight-fold reduction in the MIC of these agents, which showed a FICI ranging from 0.125 to 0.5, suggesting a synergistic interaction against methicillin-resistantStaphylococcus aureus(MRSA) strains. The combination of the aqueous extract ofP. guineensewith cefoxitin showed the lowest FICI values. This study demonstrated that the aqueous extract ofP. guineensecombined with beta lactamics antimicrobials, fluoroquinolones, and carbapenems, acts synergistically by inhibiting MRSA strains.


Author(s):  
AMRULLAH SHIDIKI ◽  
BIJAY RAJ PANDIT ◽  
ASHISH VYAS

Objective: Clindamycin is the drug of choice for the treatment of severe form of skin, soft tissue, and blood infections caused by resistant Staphylococcus aureus in the form of methicillin-resistant S. aureus (MRSA) and erythromycin-resistant S. aureus. In this research, we determine the susceptibility pattern of isolated S. aureus strains against antibiotics and the prevalence of resistant S. aureus in the form of MRSA, inducible clindamycin-resistant S. aureus (inducible macrolide-lincosamide-streptogramin B [iMLSB]) and constitutive clindamycin-resistant S. aureus (cMLSB). Methods: A total of 310 isolated S. aureus among 2000 different clinical samples were subjected to oxacillin (1 μg) as per the Kirby-Bauer disk diffusion method for MRSA. Clindamycin-resistant either in the form of iMLSB or cMLSB was determined through double disk diffusion method or D-test by use erythromycin (2 μg) and clindamycin (15 μg) as per the CLSI guidelines. Results: Out of total S. aureus, MRSA and methicillin-sensitive S. aureus (MSSA) were 78.06% and 20.64%, respectively. This study showed that iMLSB and cMLSB were 34.19% and 23.22%. Both iMLSB and cMLSB were found more among MRSA than MSSA (43.80%, 26.85% and 40.62%, 10.93%), respectively. Conclusion: This study helps for the characterization of different resistant strains of S. aureus along with the determination of the prevalence rate of these mutant forms causing nosocomial infections.


2012 ◽  
Vol 45 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Karinne Spirandelli Carvalho Naves ◽  
Natália Vaz da Trindade ◽  
Paulo Pinto Gontijo Filho

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is spread out in hospitals across different regions of the world and is regarded as the major agent of nosocomial infections, causing infections such as skin and soft tissue pneumonia and sepsis. The aim of this study was to identify risk factors for methicillin-resistance in Staphylococcus aureus bloodstream infection (BSI) and the predictive factors for death. METHODS: A retrospective cohort of fifty-one patients presenting bacteraemia due to S. aureus between September 2006 and September 2008 was analysed. Staphylococcu aureus samples were obtained from blood cultures performed by clinical hospital microbiology laboratory from the Uberlândia Federal University. Methicillinresistance was determined by growth on oxacillin screen agar and antimicrobial susceptibility by means of the disk diffusion method. RESULTS: We found similar numbers of MRSA (56.8%) and methicillin-susceptible Staphylococcus aureus (MSSA) (43.2%) infections, and the overall hospital mortality ratio was 47%, predominantly in MRSA group (70.8% vs. 29.2%) (p=0.05). Age (p=0.02) was significantly higher in MRSA patients as also was the use of central venous catheter (p=0.02). The use of two or more antimicrobial agents (p=0.03) and the length of hospital stay prior to bacteraemia superior to seven days (p=0.006) were associated with mortality. High odds ratio value was observed in cardiopathy as comorbidity. CONCLUSIONS: Despite several risk factors associated with MRSA and MSSA infection, the use of two or more antimicrobial agents was the unique independent variable associated with mortality.


2018 ◽  
Vol 146 (7-8) ◽  
pp. 384-390
Author(s):  
Milena Misic ◽  
Aleksandra Arsovic ◽  
Jelena Cukic ◽  
Milenko Rosic ◽  
Jelena Tosic-Pajic ◽  
...  

Introduction/Objective. The increasing resistance to macrolides and lincosamides among staphylococci and streptococci is becoming a global problem. The aim of this study was to investigate the prevalence of macrolide-lincosamide-streptogramin (MLS) resistance phenotypes in staphylococcal and streptococcal isolates in southeast Serbia. Methods. The MLS phenotypes were determined by the double-disk diffusion method in 2,121 inpatient and outpatient staphylococcal and streptococcal isolates collected during a one-year period at the Center for Microbiology. Results. The methicillin-resistant staphylococci isolates were significantly more resistant to penicillin, erythromycin, clindamycin, gentamicin, and ciprofloxacin (100%, 100%, 29.2%, 65.6%, and 53.1%, respectively) than the methicillin-sensitive ones (93.6%, 64.9%, 12%, 28.9%, and 11.7%, respectively). The inducible clindamycin resistance phenotype was dominant in S. aureus and coagulase-negative staphylococci isolates. S. pneumoniae, S. pyogenes, and S. agalactiae isolates showed very high resistance to erythromycin (77.8%, 46.2%, and 32.4%, respectively). All staphylococci and streptococci isolates were sensitive to vancomycin and linezolid, and all beta-hemolytic streptococci isolates to penicillin and ceftriaxone. Conclusion. The phenotypic triage of staphylococci is necessary in order to separate inducible resistant and truly clindamycin-sensitive isolates. Macrolides should not be recommended for empirical therapy of streptococcal infections. Penicillins remain the drug of choice for treatment of streptococcal infections in our local area.


Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 375
Author(s):  
Vanessa Silva ◽  
Sara Hermenegildo ◽  
Catarina Ferreira ◽  
Célia M. Manaia ◽  
Rosa Capita ◽  
...  

In this study we aimed to characterize antimicrobial resistance in methicillin-resistant Staphylococcus aureus (MRSA) isolated from bloodstream infections as well as the associated genetic lineages of the isolates. Sixteen MRSA isolates were recovered from bacteremia samples from inpatients between 2016 and 2019. The antimicrobial susceptibility of these isolates was tested by the Kirby–Bauer disk diffusion method against 14 antimicrobial agents. To determine the macrolide–lincosamide–streptogramin B (MLSB) resistance phenotype of the isolates, erythromycin-resistant isolates were assessed by double-disk diffusion (D-test). The resistance and virulence genes were screened by polymerase chain reaction (PCR). All isolates were characterized by multilocus sequence typing (MLST), spa typing, staphylococcal chromosomal cassette mec (SCCmec) typing, and accessory gene regulator (agr) typing. Isolates showed resistance to cefoxitin, penicillin, ciprofloxacin, erythromycin, fusidic acid, clindamycin, and aminoglycosides, confirmed by the presence of the blaZ, ermA, ermC, mphC, msrA/B, aac(6’)-Ie-aph(2’’)-Ia, and ant(4’)-Ia genes. Three isolates were Panton–Valentine-leukocidin-positive. Most strains (n = 12) presented an inducible MLSB phenotype. The isolates were ascribed to eight spa-types (t747, t002, t020, t1084, t008, t10682, t18526, and t1370) and four MLSTs (ST22, ST5, ST105, and ST8). Overall, most (n = 12) MRSA isolates had a multidrug-resistance profile with inducible MLSB phenotypes and belonged to epidemic MRSA clones.


2021 ◽  
Vol 10 (15) ◽  
pp. 1079-1082
Author(s):  
Priya Sinha ◽  
Sangeeta Dey ◽  
Aninda Sen ◽  
Kahkashan Akhter ◽  
Alok Kumar ◽  
...  

BACKGROUND Conjunctivitis is one of the most common nontraumatic eye complaints and is one of the most frequently reported diseases in the outpatient and emergency departments. Bacterial conjunctivitis has been reported as one of the most common type of infectious conjunctivitis after viral infections. It is also considered as the primary cause of acute conjunctivitis in children. This study was conducted to isolate and identify organisms causing bacterial conjunctivitis and to determine their in vitro susceptibility or resistance. METHODS This descriptive study was conducted in the Departments of Ophthalmology and Microbiology at Katihar Medical College from December 2018 to May 2020. Sociodemographic and clinical data were collected from 175 patients using structured questionnaire. External ocular specimens were collected using sterile swabs and inoculated on blood agar, MacConkey’s agar and chocolate agar. Presumptive isolates were further identified by a series of biochemical tests. All isolated organisms were tested for their in vitro antimicrobial susceptibility against various antibiotics using the Kirby-Baur disk diffusion method. RESULTS A total of 175 samples were collected, out of which, 62.8 % (110 / 175) showed growth of bacteria. Maximum cases of bacterial conjunctivitis were seen in the age group 11 - 20 years. The male to female ratio was 2.7:1. Maximum frequency of bacterial conjunctivitis was observed from May to September. Staphylococcus aureus was the most common bacteria isolate 65.5 % (72 / 110) followed by Staphylococcus epidermidis 19.1 % (21 / 110). Most of the Staphylococcus aureus isolates were found to be sensitive to moxifloxacin 98.6 % (71 / 72) and gentamicin 95.8 % (69 / 72). 25 % (18 / 72) of Staphylococcus aureus strains were found to be resistant to cefoxitin and were considered as methicillin-resistant Staphylococcus aureus (MRSA) strains. Maximum numbers of gram-negative strains were sensitive to moxifloxacin 100.0 % (9 / 9) followed by tobramycin 88.9 % (8 / 9). Pseudomonas aeruginosa strains showed maximum sensitivity to moxifloxacin 100.0 (8 / 8) followed by ofloxacin and ciprofloxacin 62.5 % (5 / 8). CONCLUSIONS This study provides an insight into the organisms isolated from cases of bacterial conjunctivitis in Katihar District of Bihar. Determining the susceptibility pattern of these pathogens to available antibiotics is crucial for effective management of bacterial conjunctivitis especially when treatment has to be given empirically. KEY WORDS Bacterial Conjunctivitis, Antibiogram


2004 ◽  
Vol 48 (4) ◽  
pp. 1124-1127 ◽  
Author(s):  
Hong Bin Kim ◽  
Hee-Chang Jang ◽  
Hee Jung Nam ◽  
Yeong Seon Lee ◽  
Bong Su Kim ◽  
...  

ABSTRACT Staphylococcus aureus, one of the most frequently isolated pathogens in both hospitals and the community, has been particularly efficient at developing resistance to antimicrobial agents. As methicillin-resistant S. aureus (MRSA) has prevailed and, furthermore, as S. aureus with reduced susceptibility to vancomycin has emerged, the therapeutic options for the treatment of S. aureus infections have become limited. To update the current status of antibiotic resistance, clinical S. aureus isolates were collected from eight university-affiliated hospitals from June 1999 to January 2001. Susceptibility tests with 28 antibiotics were performed by the disk diffusion method. Among a total of 682 isolates, the methicillin resistance rate was 64% (439 of 682), and most of the MRSA isolates were resistant to multiple classes of antibiotics. Although a constitutive macrolide-lincosamide-streptogramin B resistance phenotype was common, no isolates were resistant to quinupristin-dalfopristin or linezolid. Rifampin, fusidic acid, trimethoprim-sulfamethoxazole, and arbekacin showed superior in vitro activity compared with the other antibiotics against the MRSA isolates. No isolates showed reduced susceptibility to vancomycin.


1999 ◽  
Vol 37 (5) ◽  
pp. 1459-1463 ◽  
Author(s):  
Jennifer C. Seguin ◽  
Robert D. Walker ◽  
John P. Caron ◽  
Wesley E. Kloos ◽  
Carol G. George ◽  
...  

During a 13-month period, 11 equine patients visiting a veterinary teaching hospital for various diagnostic and surgical procedures developed postprocedural infections from which methicillin (oxacillin)-resistant Staphylococcus aureus (MRSA) strains were isolated. The S. aureus isolates were identified by conventional methods that included Gram staining, tests for colonial morphology, tests for clumping factor, and tests for coagulase and urease activities and were also tested with the API STAPH IDENT system. Antimicrobial susceptibility tests were performed by the disk diffusion method. The biochemical profile and antibiogram of each isolate suggested that the isolates may have come from a common source. Because MRSA strains are very uncommon animal isolates but are rather common human isolates, a nasal swab specimen for culture was collected voluntarily from five persons associated with equine surgery and recovery in an attempt to identify a possible source of the organisms. MRSA strains were isolated from three of the five people, with one person found to be colonized with two biotypes of MRSA. The MRSA isolates from the people appeared to be identical to the isolates from horses. Further study of the isolates included SmaI andEagI macrorestriction analysis by pulsed-field gel electrophoresis conducted in two different laboratories. The results indicated that both the equine and human isolates were members of a very closely related group which appear to have originated from a common source. On the basis of the pattern associated with the infection, it is speculated that the members of the Veterinary Teaching Hospital staff were the primary source of the infection, although the specific mode of transmission is unclear.


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