Molecular Investigation of Staphylococcal Cassette Chromosome mec (SCCmec) Elements Isolated from Intensive Care Unit

Background and Aims: Based on the results, Staphylococcus aureus is one of the serious infectious agents found in community and hospitals with remarkable potential for high morbidity and mortality around the globe. The present study was carried out for molecular investigation of methicillinresistant Staphylococcus aureus strains and Staphylococcal Chromosomal Cassette mec (SCCmec) phenotypes isolated from the intensive care unit in Hazrat Fatemeh Zahra hospital of Isfahan. Materials and Methods: A total of 76 clinical wound samples were collected from Hazrat Fatemeh Zahra Hospital in Isfahan and evaluated by polymerase chain reaction (PCR) methods. The Methicillin resistance Staphylococcus aureus (MRSA) screening was performed by genotypic and phenotypic methods; also antibiotic resistance pattern was determined by using the disk diffusion method and related genes by PCR. Results: Totally, 53 (69.7%) out of 76 clinical samples were positive for MRSA. Of the 76 MRSA strains, 39 (63.51%) were PVL positive (51.3%). The most commonly infected samples were collected from wounds (40.8%). The most commonly detected antibiotic resistance genes were mecA (89.61%), tetK (88.23%), tetM (49.15%) and msrA (46.93%). Resultantly, it was shown that MRSA has the highest level of resistance against methicillin (98%), penicillin (97.24%), tetracycline (89.64%). It was also revealed that the most commonly detected SCCmec types in the MRSA strains are types II (14.53%) and III (16.82%). Conclusions: In summary, this paper argues that the orderly surveillance of hospital-associated infections and initial management and supervision of the antibiotic resistance patterns are required to control the prevalence of MRSA.

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Susceptibility of Clinical Isolates of Staphylococcus aureus to Ceftaroline

JOURNAL FOR CLINICAL AND DIAGNOSTIC RESEARCH ◽

10.7860/jcdr/2021/46121.14442 ◽

2021 ◽

Author(s):

Harsha Sreedharan ◽

KB Asha Pai

Keyword(s):

Staphylococcus Aureus ◽

Tertiary Care Hospital ◽

Methicillin Resistance ◽

Descriptive Analysis ◽

Tertiary Care ◽

The United States ◽

Clinical Isolates ◽

Diffusion Method ◽

Clinical Samples ◽

Care Hospital

Introduction: Methicillin-Resistant Staphylococcus aureus(MRSA) infection is a major global healthcare problem, the prevalence of which varies from 25-50% in India. It is known to cause Skin and Soft tissue Infections (SSI), endovascular infections, endocarditis, pneumonia, septic arthritis, osteomyelitis, and sepsis. Vancomycin is the drug of choice for treating severe MRSA infections. Ceftaroline, a fifth-generation cephalosporin has been approved by the United States Food and Drug Administration (US FDA) for treating acute bacterial SSI caused by susceptible micro-organisms including MRSA, Community acquired respiratory tract infection, MRSA bacteremia and endocarditis. Aim: To assess the susceptibility of clinical isolates of S. aureusto ceftaroline, in a Tertiary Care Hospital. Materials and Methods: This prospective study was conducted in the Department of Microbiology of a Tertiary Care Hospital over a period of two months from June 2019 to July 2019. S.aureus isolates from various clinical samples were screened for methicillin resistance by disc diffusion method using cefoxitin disc and ceftaroline susceptibility of these isolates was assessed by E-strip method. The isolates were classified as ceftaroline susceptible, Susceptibility Dose Dependent (SDD) and ceftaroline resistant respectively as per CLSI guidelines. A descriptive analysis of the data was done and the results were presented as frequencies and percentages. Results: All the S.aureus isolates were found to be susceptible to ceftaroline. Methicillin Sensitive Staphylococcus aureus(MSSA) isolates had lower Minimum Inhibitory Concentration (MIC) when compared to MRSA. The highest MIC among MRSA was 0.5 μg/mL. Conclusion: Ceftaroline can be considered as an effective alternative for treatment of infections caused by MRSA.

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Prevalence of Methicillin Resistant and Virulence Determinants in Clinical Isolates of Staphylococcus aureus

The Open Infectious Diseases Journal ◽

10.2174/1874279301810010108 ◽

2018 ◽

Vol 10 (1) ◽

pp. 108-115

Author(s):

Manjunath Chavadi ◽

Rahul Narasanna ◽

Ashajyothi Chavan ◽

Ajay Kumar Oli ◽

Chandrakanth Kelmani. R

Keyword(s):

Staphylococcus Aureus ◽

Cell Morphology ◽

Methicillin Resistance ◽

Protein A ◽

Clinical Isolates ◽

Clinical Samples ◽

Virulence Determinants ◽

Methicillin Resistant ◽

Alternative Medicines ◽

Mrsa Strains

Introduction:Methicillin-resistantStaphylococcus aureus(MRSA) is the major threat that is a result of the uncontrolled use of antibiotics causing a huge loss in health, so understanding their prevalence is necessary as a public health measure.Objective:The aim of this study was to determine the prevalence of methicillin-resistant MRSA and virulence determinant among associatedS. aureusfrom the clinical samples obtained from various hospital and health care centers of the Gulbarga region in India.Materials and Methods:All the collected samples were subjected for the screening ofS. aureusand were further characterized by conventional and molecular methods including their antibiotic profiling. Further, the response of methicillin antibiotic on cell morphology was studied using scanning electron microscopy.Results:A total 126S. aureuswas isolated from the clinical samples which showed, 100% resistant to penicillin, 55.5% to oxacillin, 75.3% to ampicillin, 70.6% to streptomycin, 66.6% to gentamicin, 8.7% to vancomycin and 6.3% to teicoplanin. The selected MRSA strains were found to possessmecA(gene coding for penicillin-binding protein 2A) andfemA(factor essential for methicillin resistance)genetic determinants in their genome with virulence determinants such as Coagulase (coa) and the X region of the protein A (spa)gene. Further, the methicillin response in resistantS. aureusshowed to be enlarged and malformed on cell morphology.Conclusion:The molecular typing of clinical isolates ofS. aureusin this study was highly virulent and also resistant to methicillin; this will assist health professionals to control, exploration of alternative medicines and new approaches to combat Staphylococcal infections more efficiently by using targeted therapy.

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Antimicrobial Sensitivity Pattern in the Mixed Intensive Care Unit in a Tertiary Care Hospital of Eastern Nepal

Eastern Green Neurosurgery ◽

10.3126/egn.v2i2.29237 ◽

2020 ◽

Vol 2 (2) ◽

pp. 9-15

Author(s):

Niraj Kumar Keyal ◽

Mahendra Shrestha ◽

Partima Sigdel Ghimire

Keyword(s):

Intensive Care Unit ◽

Staphylococcus Aureus ◽

Intensive Care ◽

Tertiary Care Hospital ◽

Tertiary Care ◽

Polymyxin B ◽

Clinical Samples ◽

Care Hospital ◽

Gram Negative ◽

Sensitivity Pattern

Background: Empirical antibiotics are used in the intensive care unit based on developing countries’ guidelines due to a lack of a bacteriological profile of individual ICU and institution policy. Therefore, this study was conducted to know the antibiogram of the intensive care unit and to make institution policy for antibiotic use in ICU. Materials and methods: It was a prospective descriptive cross-sectional study conducted in the mixed surgical and medical intensive care unit of a tertiary care hospital for one year in 625 patients. Various clinical samples were collected aseptically and organisms were identified by the cultural characteristics, morphology, gram stain, and different biochemical test. Antimicrobial susceptibility was done with a disc diffusion test. Data collection was done in a preformed sheet that included all tested antibiotic and demographic variables. Statistical analysis was done by using statistical package for the social sciences. The result was presented as frequency and percentage. Results: Out of 625 samples, 135(22%) showed growth in culture. Among them, 96(71%) and 39(29%) were gram-negative bacilli and gram-positive cocci respectively. The tracheal aspirate was the most common type of specimen which comprised 49(36.29%) isolates. The most common organism was Staphylococcus aureus which accounts for 27(20%) isolates, followed by Acinetobacter baumanni 25(18.51%), Klebsiella pneumoniae 22(16.29%) and Pseudomonas aeurignosa 21(15.55%). The incidence of multidrug-resistant and extended drug resistance was 44(32.5%) and 45(33%) respectively. Meanwhile, the incidence of methicillin-resistant staphylococcus aureus was 70%. However, in the case of Acinetobacter baumannii and Enterobacteriaceae, all were sensitive to polymyxin B and meropenem. Conclusion:Antibiotics should be prescribed based on the antibiogram of individual intensive care units that can decrease antibiotic resistance. Polymyxin B and meropenem can be prescribed for gram-negative bacilli and vancomycin for Staphylococcus aureus.

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Peculiarities of antibiotic resistance of Staphylococcus aureus strains isolated from nosocomial infections

Kazan medical journal ◽

10.17816/kmj2020-325 ◽

2020 ◽

Vol 101 (3) ◽

pp. 325-329

Author(s):

S A Atakishizade

Keyword(s):

Antibiotic Resistance ◽

Nosocomial Infections ◽

Methicillin Resistance ◽

Surgical Site Infections ◽

Diffusion Method ◽

Methicillin Resistant ◽

Inducible Clindamycin Resistance ◽

Significant Difference ◽

Microbiological Testing ◽

Mrsa Strains

Aim. To study of the antibiotic resistance of S. aureus strains isolated from nosocomial infections (pneumonia, surgical site infections and sepsis) in a multidisciplinary surgical clinic. Methods. Microbiological testing of sputum in 41 patients with pneumonia, of samples (wound, abscess, drainage) obtained from 40 patients with surgical site infections (SSI) and of blood from 46 patients with signs of sepsis was performed. The obtaining cultures were identified by conventional methods (including morphological, cultural, biochemical features, etc.). Disc diffusion method was used to detect methicillin-resistant S. aureus (MRSA) strains. Inducible clindamycin resistance (ICR) of S. aureus strains was determined by double disk approximation test (D-test). Results. Methicillin-resistant S. aureus was found in 14.3% (2 of 14) of the patients with surgical site infections, in the sputum 27.3% (3 of 11) of the patients with pneumonia, and in the blood 50.0% (7 of 14) of the patients with sepsis (p 0.05). The rate of inducible clindamycin resistance of isolated S. aureus strains in patients with surgical site infections (2 of 14 cases, 14.3%) and with pneumonia (2 of 11 cases, 18.2%) did not statistically significant difference with the rate of methicillin resistance (p 0.05). However the rate was significantly lower septic infections 7.1% and 50.0% respectively (p=0.0328). Conclusion. Among S. aureus strains isolated from nosocomial infections, the rate of methicillin-resistant S. aureus had not depended on the type of nosocomial infection; the rate of inducible clindamycin resistance in septic infections was lower than resistance to methicillin.

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Determination of minimum inhibitory concentration (MIC) of cloxacillin for selected isolates of methicillin-resistant Staphylococcus aureus (MRSA) with their antibiogram

Bangladesh Journal of Veterinary Medicine ◽

10.3329/bjvm.v6i1.1350 ◽

1970 ◽

Vol 6 (1) ◽

pp. 121-126 ◽

Cited By ~ 14

Author(s):

MA Islam ◽

MM Alam ◽

ME Choudhury ◽

N Kobayashi ◽

MU Ahmed

Keyword(s):

Staphylococcus Aureus ◽

Minimum Inhibitory Concentration ◽

Inhibitory Concentration ◽

Agar Plate ◽

Susceptibility Test ◽

Diffusion Method ◽

Clinical Samples ◽

Methicillin Resistant ◽

Antibiotic Susceptibility Test ◽

Mrsa Strains

The minimum inhibitory concentration (MIC) represents the concentration of antimicrobial at which there is complete inhibition of growth of organism. In order to determine the MIC of cloxacillin, 10 MRSA were previously detected from 40 clinical isolates of Staphylococcus aureus by polymerase chain reaction (PCR). Agar plate dilution test was used to determine the MIC of cloxacillin. The clinical samples were collected from Mymensingh Medical College Hospital, Mymensingh. The study was done in the Department of Medicine, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh from July 2006 to June 2007. The MIC of the cloxacillin for 5 MRSA strains were â¥32 (mg/ml), for 1 MRSA strain was â¥ 128(mg/ml) and for another 4 MRSA strains were above â¥128 (mg/ml). Antimicrobial susceptibility test of the isolated organisms were done by disc diffusion method. On antibiotic susceptibility test, MRSA strains showed 100% resistant against penicillin, oxacillin, cloxacillin and amoxycillin. Cent per cent susceptibility of MRSA was found against vancomycin, ciprofloxacin, erythromycin, fusidic acid and rifampicin. Key words: Minimum inhibitory concentration (MIC), antibiotic resistance, cloxacillin, methicillin-resistant Staphylococcus aureus (MRSA) DOI = 10.3329/bjvm.v6i1.1350 Bangl. J. Vet. Med. (2008). 6 (1): 121-126

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Detection of Virulence Factors and Antibiotic Resistance Pattern of Clinical and Intensive Care Unit Environmental Isolates of Pseudomonas aeruginosa

Infectious Disorders - Drug Targets ◽

10.2174/1871526520666191231124717 ◽

2020 ◽

Vol 20 (5) ◽

pp. 758-762

Author(s):

Omid Zarei ◽

Hassan Mahmoudi ◽

Ali Mohammadi Bardbari ◽

Pezhman Karami ◽

Mohammad Yousef Alikhani

Keyword(s):

Intensive Care Unit ◽

Pseudomonas Aeruginosa ◽

Antibiotic Resistance ◽

Intensive Care ◽

Virulence Factors ◽

Opportunistic Pathogen ◽

Diffusion Method ◽

Resistance Pattern ◽

Disk Diffusion Method ◽

Human Infections

Background: Pseudomonas aeruginosa is a gram-negative non-glucose fermenting aerobic bacteria and an opportunistic pathogen in humans and animals. The present study was carried out to investigate the distribution of virulence factors and antibiotic resistance properties of P. aeruginosa isolated from patients and intensive care unit (ICU) environment. Material and Methods: A total of 116 P. aeruginosa isolated from patients and ICU environment were collected from Besat hospital in Hamadan, the West of Iran. P. aeruginosa isolates were analyzed based on the presence of the virulence factors encoding genes included exoA, exoS, exoU, and algD using polymerase chain reaction (PCR). Antimicrobial susceptibility test was performed using a disk diffusion method. Results: The results showed the prevalence of exoA 33 (56.9%), exoS 21 (36.20%), exoU 37 (63.8%), and algD 35 (60.34%) genes in ICU environment P. aeruginosa strains and exo A 23 (39.25%), exoS 25 (43.1%), exoU 40(68.98%), and algD 25 (43.1%) genes in clinical isolates of P. aeruginosa. High resistance levels of the clinical and ICU environment isolate to ampicillinsulbactam (100%), were also observed. Conclusions: Our findings should raise awareness about antibiotic resistance in hospitalized patients in Iran. Clinicians should exercise caution in prescribing antibiotics, especially in cases of human infections.

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Is Methicillin-Resistant Staphylococcus Aureus More Contagious than Methicillin-Susceptible S. Aureus in a Surgical Intensive Care Unit?

Infection Control and Hospital Epidemiology ◽

10.1086/502094 ◽

2002 ◽

Vol 23 (9) ◽

pp. 491-494 ◽

Cited By ~ 45

Author(s):

Menno R. Vriens ◽

Ad C. Fluit ◽

Annet Troelstra ◽

Jan Verhoef ◽

Chris van der Werken

Keyword(s):

Intensive Care Unit ◽

Staphylococcus Aureus ◽

Intensive Care ◽

Methicillin Resistance ◽

Surgical Intensive Care Unit ◽

Surgical Intensive Care ◽

Methicillin Resistant ◽

Active Screening ◽

Screening Programs ◽

Surgical Icu

Background and Objective:In the Netherlands, the prevalence of methicillin resistance among Staphylococcus aureus isolates has been kept to less than 1% by using active screening programs and isolation. At the University Medical Center Utrecht (UMCU), an active screening program for methicillin-resistant S. aureus (MRSA) in the surgical intensive care unit (ICU) was implemented in 1986. Between 1992 and 2001, only 6 patients with MRSA were admitted to the surgical ICU. However, 4 of these 6 strains were able to spread to 23 other patients and 15 healthcare workers (HCWs). We were surprised by the epidemic behavior of these strains and wondered whether this was exceptional for S. aureus or whether methicillin-susceptible S. aureus (MSSA) was also spreading in the ICU.Design:A 2-month, prospective, observational study to investigate the incidence and spread of MSSA in the surgical ICU of UMCU and historical data collected during a 10-year period regarding MRSA.Setting:A 10-bed surgical ICU in a 1,042-bed teaching hospital.Results:Weekly swabs revealed the presence of MSSA in 11 (24%) of 45 patients and 16 (22%) of 72 HCWs. Of all 4,105 patient–HCW contacts, there were only 21 episodes in which both the patient and the HCW were found to carry MSSA. With the use of pulsed-field gel electrophoresis, no identical strains could be identified.Conclusion:In our surgical ICU, MRSA seems to spread more easily than MSSA, probably because of selection under antibiotic pressure or a still unknown intrinsic factor within MRSA.

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Prevalence of methicillin resistance and superantigenic toxins in Staphylococcus aureus strains isolated from patients with cancer

BMC Microbiology ◽

10.1186/s12866-021-02319-7 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Effat Abbasi Montazeri ◽

Azar Dokht Khosravi ◽

Saeedeh Khazaei ◽

Ali Sabbagh

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Cancer Patients ◽

Methicillin Resistance ◽

Resistance Pattern ◽

Patients With Cancer ◽

Resistance Patterns ◽

Mrsa Strains ◽

Southwest Iran ◽

Antibiotic Resistance Patterns

Abstract Background This study aimed to determine the frequency of methicillin-resistant Staphylococcus aureus (MRSA), antibiotic resistance patterns, superantigenic toxins profile, and clonality of this pathogen in patients with cancer. Results In total, 79 (25.7%) isolates were confirmed as Staphylococcus species, from which 38 (48.1%) isolates were S. aureus, and 29 (76.3%) isolates were confirmed as MRSA. The highest resistance in MRSA strains was seen against ciprofloxacin (86.2%) and erythromycin (82.8%). Teicoplanin, and linezolid were the most effective antibiotics. From all MRSA isolates, 3 strains (10.3%) were resistant to vancomycin with minimum inhibitory concentration values of 128 μg/ml. The prevalence of superantigenic toxins genes was as follows: pvl (10.5%), tsst-1 (36.8%), etA (23.7%), and etB (23.7%). The t14870 spa type with frequency of 39.5% was the most prevalent clone type circulating in the cancer patients. Conclusions This study showed the circulating of spa t14870 as the most predominant MRSA clone in cancer patients of southwest Iran. Also, a diverse antibiotic resistance pattern and toxin profiles were seen among MRSA isolates.

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Monitoring of multiresistant community-associated MRSA strains from patients with pathological processes of different localization

Regulatory Mechanisms in Biosystems ◽

10.15421/021841 ◽

2018 ◽

Vol 9 (2) ◽

pp. 281-286

Author(s):

T. V. Sklyar ◽

K. V. Lavrentievа ◽

V. G. Gavrilyuk ◽

N. V. Kurahina ◽

M. O. Vereshchaha ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Nasal Cavity ◽

Fusidic Acid ◽

Threshold Value ◽

Urine Samples ◽

Diffusion Method ◽

Clinical Samples ◽

Methicillin Resistant ◽

Vancomycin Resistant ◽

Mrsa Strains

The therapy of infections, caused by methicillin-resistant Staphylococcus aureus (MRSA) with multiple resistance to antibiotics remains one of the most acute problems all over the world. It is all the more complicated since a priori the MSRA strains are not sensitive to the group of β-lactam antibiotics and multiresistant isolates are resistant to other groups of antimicrobial preparations, including antibiotics of choice (rifampicin, vancomycin, fusidic acid, co-trimoxazole and linezolid). From the samples of biomaterials of patients with pathological processes of different localization, we isolated 335 strains of bacteria, which were identified as Staphylococcus aureus, 169 (50.4%) of which were methicillin-resistant variants: 57.5% cultures were isolated from the nasal discharge; 50.7% – from faeces at intestinal dysbioses; by 40.0% – from conjunctival discharge, pharyngeal swab, outer ear swab and sputum; 33.3% – from urine samples. Antibiotic susceptibility of the isolated cultures was estimated by the disc-diffusion method and the method of serial dilution. The MRSA strains appeared to be most resistant to gentamycin, erythromycin (by 59.5% of cultures) and ciprofloxacin (53.3% of isolates), most sensitive – to vancomycin, co-trimoxazole and fusidic acid. The frequency of isolation of the cultures that are resistant to antibiotics did not exceed 4.1%. Rifampicin suppressed the growth of 75.8% and linezolid – of 100.0% of strains. Depending on the kind of biomaterial taken, MRSA strains, isolated from the nasal cavity, outer ear, urine samples, samples of sputum and faeces at intestinal dysbioses proved to be most resistant to the tested antimicrobial preparations. Rifampicin- and vancomycin-resistant strains of methicillin-resistant staphylococci made up 21.3% of the total number of the detected MRSA. They were most often isolated from the clinical samples taken from the nasal cavity and faeces. When determining minimal inhibitory concentration (MIC) of rifampicin and vancomycin, which are antibiotics of choice for treatment of infections caused by multiresistant MRSA, it was found that for 55.5% of the MRSA strains isolated from faeces, MIC of rifampicin coincided with the threshold value for this antibiotic and for 44.5%, it exceeded the threshold value by 2 times (4 µg/ml). 22.2% of them were characterized by the critical value of susceptibility to vancomycin (MIC ≥ 2 µg/ml). From rifampicin- and vancomycin-resistant MRSA stains, isolated from the nasal cavity, MIC of rifampicin coincided with the threshold value for this antibiotic for 66.7% of cultures, and exceeded it at least by 2 times for 33.3%. 11.1% of them were characterized by the critical level of susceptibility to vancomycin (MIC ≥ 2 µg/ml) and by 3.7% of strains exceeded MIC by 2 and 4 times respectively (4 and 8 µg/ml).

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Prevalence of MRSA and Antimicrobial Susceptibility Staphylococcus aureus in Clinical Samples in National Capital Region, India

Journal of Pharmaceutical Research International ◽

10.9734/jpri/2021/v33i59a34266 ◽

2021 ◽

pp. 209-215

Author(s):

Pradeep Kumar ◽

Geeta Gupta ◽

Gajendra Kumar Gupta ◽

Vashishth Mishra ◽

Gaurav Gupta

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistance ◽

Tertiary Care ◽

Clinical Samples ◽

National Capital Region ◽

Medical College ◽

Diffusion Technique ◽

National Capital ◽

Mrsa Strains ◽

Transmission Capability

Background: Infections caused by Staphylococci are frequently linked to indwelling medical equipment. These are extremely difficult to treat with antibiotics. In India, the prevalence of Methicillin-Resistant Staphylococcus aureus (MRSA) varies from 30 to 70%, resulting in high mortality, increased economic burden, and high treatment failure in tertiary care hospitals. Rapid and reliable identification of MRSA is critical for infection management and avoiding the needless use of antibiotics. Materials and Methods: This prospective study was carried out in the Department of Microbiology, Santosh Medical College, Ghaziabad, from the 1st of August 2020 to the 31st of January 2021. MRSA isolates were screened and confirmed using standard methods recommended by the Clinical and Laboratory Standards Institute (CLSI). Methicillin resistance, in Staphylococcus aureus strains, was evaluated using oxacillin/cefoxitin. The Kirby-Bauer disc diffusion technique was used to assess the antibiotic susceptibility pattern of all MRSA strains. Results: In this investigation, MRSA was identified in 29.4% of the 384 Staphylococcus aureus strains. When compared to females, men outnumbered females. Cefoxitin detects a greater amount of MRSA than oxacillin. In this investigation, the majority of MRSA was found in pus samples. Conclusion: MRSA prevalence is known to vary depending on geographical region, hospital type, investigated population, and technique of detection used. Given the clinical implications of MRSA infection and its fast transmission capability, MRSA strains must be monitored on a regular basis.

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