Dear Label_Name,

Greetings! I hope you are well.

I am writing on behalf of an international publishing house, Science and Education Publishing, USA (http://www.sciepub.com).

Science and Education Publishing (SciEP) is a multidisciplinary open access publisher of Journals covering the fields of Science, Technology and Medicine. All SciEP publications are subject to high-quality peer review, editorial and production processes and are freely available online.

Welcome to the April, 2013 edition of SciEP newsletter, providing monthly summaries of articles on science & education related topics of interest to scientist and professionals. The mission of our journals is to provide an open access forum for publishing new findings on issues pertinent to scientific and academic field. We also invite you to submit original research papers, review articles, short reports, or case studies are considered for publication in our Multidisciplinary Journals.

American Journal of Public Health Research
DOI: 10.12691/ajphr-1-1-3

The Implementation of a Tele-Homecare System with Service Oriented Architecture and HL7 Message Transmission Standard
Ching-Sung Wang

American Journal of Medical and Biological Research
DOI: 10.12691/ajmbr-1-1-2

The Influence of Ethanol on Pyruvate Kinases Activity in Vivo, in Vitro, in Silico
Lelevich Sergey Vladimirovich, Khrustalev Vladislav Victorovich, Barkovsky Eugene Victorovich, Shedogubova Tatyana Aleksandrovna

American Journal of Medical Sciences and Medicine
DOI: 10.12691/ajmsm-1-1-1

Clinical and Histological Features in Wegener Granulomatosis
Li Cavoli Gioacchino, Passantino Rita, Bono Luisa, Tortorici Calogera, Ferrantelli Angelo, Giammarresi Carlo, Rotolo Ugo

American Journal of Infectious Diseases and Microbiology
DOI: 10.12691/ajidm-1-1-2

The Curse of Lymphatic Filariasis: Would the Continual Use of Diethylcarbamazine Eliminate this Scourge in Papua New Guinea?
Anne Lanham, Lillian Mwanri

We have released issues of some journals on February 2013.
American Journal of Public Health Research
American Journal of Medical Sciences and Medicine
American Journal of Medical and Biological Research
American Journal of Pharmacological Sciences
American Journal of Clinical Medicine Research
American Journal of Nursing Research
American Journal of Cancer Prevention
American Journal of Medicine Studies
American Journal of Infectious Diseases and Microbiology
American Journal of Cardiovascular Disease Research
American Journal of Biomedical Research
American Journal of Mechanical Engineering
American Journal of Microbiological Research
Journal of Preventive Medicine
American Journal of Food and Nutrition
American Journal of Hypertension Research
American Journal of Sports Science and Medicine
Journal of Cancer Research and Treatment
American Journal of Zoological Research
Journal of Biomedical Engineering and Technology
American Journal of Microbiological Research
Biomedical Science and Engineering

We are pleased to announce that submissions are now being accepted for peer review for all the journals across all our subject areas in SciEP.

Please submit your manuscript via our online submission system:
http://www.sciepub.com/author/signin

To unsubscribe from our mailing list, please click on the following link: unsubscribe

I am looking forward to hearing from you.

Kind regards,

David Rain
Email:join@sciepub.com
Science and Education Publishing (http://www.sciepub.com)

Investigation on Vancomycin Resistance (VRSA) among Methicillin Resistant S. aureus (MRSA) in Khartoum State, Sudan

Marwa Mohamed Osman*, Muataz Mohamed Osman, Nihal Abdulla Mohamed, Samah Mohamed Osman, Mamoun Magzoub, Suliman Mohamed El-Sanousi

Department of Biotechnology, Africa city of Technology, Khartoum, Sudan

Abstract: Background: Staphylococcus aureus is one of the most important and frequent cause of nosocomial infections worldwide. This study was carried out to investigate the prevalence of Vacomycin-Resistant Staphylococcus aureus and antibiotic sensitivity pattern in clinical isolates in Khartoum. Methods: One hundred and thirty three various samples were collected from some hospitals in Khartoum over a period of 5 months. The samples were cultured on bacteriological media for the isolation of Staphylococcus aureus using standard methods of isolation and identification of bacteria. The Staphylococcus aureus were tested for Methicillin susceptibility using 5 μg Oxacillin disc and Oxacillin E-test, with Resistance defined as an MIC of ≥ 4µg/ ml. Results: In this study all MRSA isolates displayed an Oxacillin MIC of ≥256µg/ml. The MRSA strains were 41.0% while the Resistance to vancomycin was examined by vancomycin E-test, with resistance defined as an MIC of ≥16 µg ml. In this study all VSSA isolates displayed vancomycin MIC of ≤ 2µg/ml "except three intermediate resistant isolate MIC between 4-8 µg/ml". The percentage of the VISA strains was 12.0%. Discussion: The unprevalence of resistance to vancomycin may be related to the low usage of this antibiotic in this study area The majority MRSA isolates were multidrug-resistant (MDR) to different classes of antibiotics including; amoxicillin /clavulinic acid, ampicillin, tetracycline, erythromycin clindamycin and ciprofloxacin. Nitroforantoine exhibit no resistant pattern while 92% of MRSA isolates were susceptible to chloramphenicol. The unprevalence of resistance to Vancomycin may be related to the low usage of this antibiotic so Vancomycin might be used as a drug of choice for the treatment of MRSA infection.

Keywords: prevalence, MRSA, VRSA, Khartoum, Sudan

Citation: Marwa Mohamed Osman, Muataz Mohamed Osman, Nihal Abdulla Mohamed, Samah Mohamed Osman, Mamoun Magzoub, Suliman Mohamed El-Sanousi, Investigation on Vancomycin Resistance (VRSA) among Methicillin Resistant S. aureus (MRSA) in Khartoum State, Sudan. American Journal of Microbiological Research, 4 (2). 56-60. January 2016. doi:10.12691/ajmr-4-2-2

1. Introduction

Staphylococcus aureus is one of the most important a frequent cause of nosocomial infections worldwide [1]. Emergence of Methicillin-resistant S. aureus strain (MRSA) in 1961 made staphylococcal infections as a major therapeutic challenge [2]. Methicillin Sensitive S. aureus (MSSA) and Methicllin Resistant S. aureus (MRSA). MRSA strains have been associated with a or hospital acquired infections world over and have also emerged as an important cause of community acquired infections [3]. MRSA infections are a problem across the whole health economy, and have been shown to be associated with a poorer outcome and higher mortality than similar infections caused by Methicllin-sensitive strains of S. aureus (MSSA).

Many of these isolates are becoming multidrug resistant and are susceptible only to glycopeptides antibiotics such as Vancomycin [4] Vancomycin-resistant Staphylococcus aureus (VRSA) infections, which are always methicillin-resistant, are a rare but serious public health concern [5]. In 1988, vancomycin-resistant enterococci (VRE) were first reported. These organisms quickly became endemic in hospital intensive care units. In vitro conjugative transfer of the vanA gene from enterococci to S.aureus was demonstrated in 1992. However, it was not until 1996, when the first case of vancomycin intermediate S.aureus (VISA; MIC, 8–16 µg/mL) was detected, that decreased susceptibility to vancomycin became a clinical reality. None of the VISA strains identified contained the vanA gene or any of the other vancomycin-resistant genes found in VRE. In vitro studies suggest that, with prolonged vancomycin exposure, VISA organisms produce a thickened cell wall matrix, limiting drug penetration [6,7]. Recently, however, due to the use of Vancomycin for treatment of hospital-based infections, there has been growing resistance to Vancomycin by species such as Enterococcus [8]. The emergence of Vancomycin resistance in Enterococcus gave rise to the possibility of horizontal transmission of resistance elements to S. aureus. In the laboratory, Vancomycin resistance has been transferred from Enterococcus faecalis to S. aureus [9]. The objective of our study was to determine the prevalence of Vancomycin resistance Staphylococcus aureus (VRSA) among Methicillin resistant S. aureus (MRSA) in Khartoum State.

2. Methods

This cross sectional study was conducted during the period of March to October 2015. Swabs of wound, skin (axella, groin), sputum, ear, and throat, also urine, blood and body fluids and sputum specimens were collected. Patients in Intensive Care Unit (ICU) and wards, nasal swabs were collectred from different Khartoum hospitals after obtaining consent. Patients were aged between days to 84 years from both sexes. Mannitol Salt Agar, Müeller Hinton agar, Nutrient agar, Nutrient broth and DNAase Agar media were prepared in laboratory depending on the manufacturers' instruction. S. aureus were identified by fermentation of mannitol, colony morphology, Gram stain, Catalase test and sub-cultured on nutrient agar for coagulase test and deoxyribonuclease (DNase) test by conventional methods. All MRSA strains were determined by disk diffusion method using and confirmed by MIC (bioMerieux) method using the Oxacillin E-test then by Vancomucin E-test for VRSA strains according to National Committee for Clinical Laboratory Standards [10]. The following antibiotic disks were tested: Oxacillin, (OX 5μg), Vancomycin (VA 30μg), Ampicillin/Cavulinic acid (AMC 10μg), Amoxicillin (AMX 10μg), Tetracyclin (TE 30μg), Erythromycin (E 15μg), Gentamycin (GEN 10μg), Ciprofloxacin (CIP 5μg), Clindamycin (CD 2μg), Chloramphenicol (C 30μg) Ceftrixone (CTR 30μg), Trimethoprim-sulphanimide (COT 30μg, Nitrofurantoin (NIT 300μg) and Meropenem (MEM 10 μg). Potential anti-MRSA synergy was measured by fractional inhibitory concentration indices (FICI) This could be calculated as: The FIC of drug ‘A’, given by FICA = MICA combination / MICA alone while The FIC of drug ‘B’, given by FICB = MICB combination /MICB alone The FIC index of the combination in each tube is given by the sum of the FICs for each of the drugs present in the tube: FIC index = FICA + FICB [11].

2.1. Statistical Analysis

Statistical analyses were conducted using SPSS (version 20; SPSS Inc., Chicago, IL) software. Descriptive analyses of percentages of categorical variables were reported using chi square x². p value of < 0.05 denoted a statistically significant difference in all statistical comparisons.

2.2. Ethical Clearance

This study was approved by ethical clearance committee, Department of Microbiology- Tropical Medicine Research Institute., Khartoum, Sudan.

3. Results

Out of the 135 bacteria isolated from clinical specimens, 79(58.5%) were identified to be Staphylococcus species. Only 61 (97.2%) were Identified biochemically to be S. aureus, out of this 36(59%) Methicillin Sensitive S. aureus (MSSA) and 25(41%) Methicllin Resistant S. aureus (MRSA), Figure 1, Figure 3. MRSA were collected from patients in ICU units and wards from different Khartoum hospitals. Resistance to Methicillin was determined by two methods: Agar diffusion test to detect oxacillin (≤ 10 mm) was considered resistant (3.9) and E-test for determination of Oxacillin Minimum Inhibitory Concentration (MIC).

Figure 1. Distribution of S. aureus isolates (MRSA/MSSA)

The resistance defined as an MIC of ≥4 µg/ml (10). In this study all MRSA isolates displayed an Oxacillin MIC of ≥256µg/ml. Resistance to vancomycin was determined by two methods: Agar diffusion test to detect vancomycin resistance (≤ 9 mm) was considered resistant (12) and E-test for determination of vancomycin MIC. The resistance defined as an MIC ≥16 µg/ml (5,10). In this study all VSSA isolates displayed vancomycin MIC of < 2µg/ml "except three intermediate resistant isolates MIC between 4-8 µg/ml" The percentage of the VISA was 12.0%, Table 1, Figure 4. We found a VISA strain in a patient who had underlying conditions including immunosuppressive therapy, long-time hospitalization, and serious disease. The majority of the MRSA isolates were resistant to multiple antimicrobial agents, in this study out of 25 MRSA strains isolated, exhibited high resistance to different classes of antibiotics including; Amoxicillin/Clavulinic acid and Ampicillin (100%), Ceftriaxone and Erythromycin (80%), Meropenem (60%), Ciprofloxacin, Clindamycin and Trimetoprim-Sulphanomide (56%), and Tetracycline (44%). Nitroforantoie exhibit no resistant pattern (100%) while 92% of MRSA isolates were susceptible to Chloramphenicol Table 2. No synergistic effects were detected from the above mentioned combined antibiotics according to FICI.

Figure 2. prevalence of MRSA/MSSA strains obtained from different clinical specimens in Khartoum state

Figure 3. E-test technique for MRSA/MSSA strains (a) MRSA strain with MIC > 256 µg/ml and (b) MSSA strain with MIC = 2µg/ml

Figure 4. VISA strains by E-test method: (a) MIC =4 µg/ml, (b) MIC= 8 µg/ml

Table 1. Prevalence of VISA/VSSA obtained from clinical specimens according to E-test method (BíomMéríeux) of vancomycin

Table 2. Antimicrobial resistance pattern of MRSA obtained from clinical specimens

4. Discussion

In our study Oxacillin disk could not detect all MRSA isolates but Oxacillin MIC test had determined these MRSA isolates. Our result is similar to a study conducted in Iran [13]. It showed that the sensitivity of Cefoxitin disk and Oxacillin MIC test equal to PCR. Disc diffusion method of Vancomycin did not differentiate between VISA and VSSA strains. So the result is not considered unless the MIC of Vancomycin is used according to NCCLS. Besides those MRSA isolates, Coagulase Negative Staphylococcus (CoNS) was also isolated from clinical specimens in two patients. One of them was found to be methicillin and vancomycin resistant and the other was methicillin and vancomycin susceptible. Methicillin resistant coagulase negative isolate may be a result of the horizontal transfer of mecA gene between MRSA and coagulase negative staphylococcal species. In our study, all isolates ´except three intermediate resistant isolates in which MIC values between 4-8 μg/ml` were susceptible to vancomycin. They displayed MICs of < 2 μg/ml). The unprevalence of resistance to vancomycin may be related to the low usage of this antibiotic in the study area. Also our result substantiated the result of the study carried out in Khartoum [14]. Antibiotics resistance has become a serious public health concern with economic and social implications throughout the world, being community acquired infections like Streptococcal infections, pneumonia, typhoid fever or hospital acquired infections due to MRSA, VRE, VISA or extended spectrum β -lactamase (ESBL) enzyme producing Gram -ve bacteria.

These infections lead to higher rates of hospitalization, longer hospital stay, and increased cost of treatment and thus increased economic burden on the community [15]. MRSA strains were sensitive to Nitroforantoie, Chloramphenicol (100%), (92%) respectively while they were highly resistant to antibiotics including; amoxicillin /clavulinic acid and ampicillin (100%), ceftriaxone and erythromycin (80%), meropenem (60%), ciprofloxacin, clindamycin and trimetoprim- sulphanomide (56%), and tetracycline (44%). Our results go with the results of a study conducted in Sudan [4] that revealed a cross-resistance of MRSA strains. The rapid proliferation of antibiotic-resistant pathogens has spurred the use of drug combinations to maintain clinical efficacy and combat the evolution of resistance. Drug pairs can interact synergistically or antagonistically, yielding inhibitory effects larger or smaller than expected from the drugs’ individual potencies. The inhibitory effect of two drugs in combination can be larger or smaller than expected from their individual effects, corresponding to synergistic or antagonistic interactions between the drugs respectively. Synergistic interactions are usually thought of as advantageous since, for a given amount of drug. They inhibit the growth of drug-sensitive pathogens more effectively. However, in vitro studies have suggested that, for the same level of inhibition, more synergistic drug pairs may foster antibiotic resistance. Antagonistic drug combinations, on the other hand, are less effective at inhibiting drug-sensitive pathogens, but can reduce and even invert the selective advantage of single-drug resistant mutants, causing selection against resistance [16]. While this is so, we recommend more combinations of different antibiotics to solve this resistant problem.

5. Conclusion

In conclusion, S. aureus is highly prevalent in Khartoum hospitals, Sudan. MRSA is highly prevalent among populations of S. aureus isolated from different clinical specimens in different hospitals in Khartoum State, Sudan, with most of the MRSA isolates being from ICU patients.

The unprevalence of resistance to vancomycin may be related to the low usage of this antibiotic in the study area where it is used as a drug of choice for the treatment of MRSA infection.

Acknowledgments

The authors wish to acknowledge Professor Hassan Bashir EL-Amin for his helpful advice, Ms. Hadia in Zaitona hospital and Ms. Kamylia in ENT Hospital for their help in sample collection.

Competing Interests

The authors declare that they have no competing interests.

References

[1]   | Kluytmans J.A., Wertheim H.F. Nasal carriage of Staphylococcus aureus and prevention of nosocomial infections. Infection. 2005; 33: 3-8.
[2]   | Tarai B, Das P, Kumar D. Recurrent Challenges for Clinicians: Emergence of Methicillin-Resistant Staphylococcus aureus, Vancomycin Resistance, and Current Treatment Options. Journal of Laboratory Physicians. 2013;5(2):71-78.
[3]   | Kaur, H. et al. Susceptibility testing and resistance phenotypic detection in Staphylococcus aureus by conventional and molecular methods: Importance of automated (Vitek 2) system. International Journal of Engineering Research and Development. 2012; 3(10): 68.
[4]   | Kheder, S.I et al. Prevalence and Antimicrobial Susceptibility Pattern of Methicillin Resistance Staphylococcus in a Sudanese Surgical Ward. Pharmacology & Pharmacy, 2012; 3: 103-108.
[5]   | Jennie Finks, Eden Wells, Teri Lee Dyke, Nasir Husain, Linda Plizga, Renuka Heddurshetti, Melinda Wilkins, James Rudrik, Jeffrey Hageman, Jean Patel, and Corinne Miller, Vancomycin- Resistant Staphylococcus aureus, Michigan, USA, Emerg Infect Dis. 2009 Jun; 15(6): 943-945.
[6]   | Centers for Disease Control and Prevention. Vancomycin-Resistant Staphylococcus aureus – Pennsylvania. Morbid. Mortal. Weekly Rep 2002; 51: 902.
[7]   | Banerjee T., Anupurba S. (2012). Colonization with Vancomycin Intermediate Staphylococcus aureus Strains Containing the vanA Resistance Gene in a Tertiary-Care Center in North India. J. Clin. Microbiol. 50 (5): 1730-1732.
[8]   | Neu, H.C. The Crisis in Antibiotic Resistance. Science 1992; 257: 1064-1072.
[9]   | Cookson, B., A.C. Fluit and F.J. Schmitz. Introduction. In A.C. Fluit & F.J. Schmitz (Eds.), MRSA Current Perspectives (pp. 1-9). Norfolk, England: Caister Academic Press 2003 pp. 1-9.
[10]   | Clinical Laboratory Standards Institute. Performance Standards for Antimicrobial Susceptibility Testing; Twenty-Second Informational Supplement 2012; CLSI document M100-S22.32, 3:44-70
[11]   | Kyaw B.M, arora S., Chu Sing Lim C.S. Bactericidal antibiotic- phytochemical combinations against methicillin resistant Staphylococcus aureus. Braz J Microbiol 2012; 43(3): 938-945.
[12]   | C. P. KOLBERT, J. ARRUDA, P. VARGA-DELMORE, X. ZHENG, M. LEWIS, J. KOLBERG and D. H. PERSING. Branched-DNA Assay for Detection of the mecA Gene in Oxacillin-Resistant and Oxacillin-Sensitive Staphylococci. JOURNAL OF CLINICAL MICROBIOLOGY, 1998;36 (9): 2640-2644.
[13]   | Solmaz D., Mohsen A., Elham J., and Reza S. Prevalence and antimicrobial resistance pattern of methicillin resistant Staphylococcus aureus (MRSA) strains isolated from clinical specimens in Ardabil, Iran. Iran J Microbiol. 2014; 6 (3): 163-168.
[14]   | Misk Elyamen A. E., Mogahid M. E., Omar B. A., B. and Elfadil E.O. Molecular Detection of Methicillin Resistant Staphylococcus aureus in Patients with Urinary Tract Infections in Khartoum State. Journal of Science and Technology 2014; 15(1): 1-8.
[15]   | Kapil A. The challenge of antibiotic resistance: Need to contemplate. Indian J Med. 2005; 121: 83-91.
[16]   | Torella J.P., Chait R., Kishony R. Optimal Drug Synergy in Antimicrobial Treatments. PLoS Comput Biol. 2010; 6(6): e1000796.