High prevalence of multidrug-resistant MRSA in a tertiary care hospital of northern India

Antimicrobial Susceptibility Profile of Methicillin-Resistant Staphylococcus Aureus Isolated from Clinical Samples at Bac Ninh Provincial General Hospital, Vietnam

Purpose

Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA) strain, can become resistant to all classes of clinically available antibiotics and causes skin infections and severe infections in the lungs, heart, and bloodstream. The study aimed to evaluate antimicrobial susceptibility patterns and MRSA exhibiting multidrug resistance obtained through a microbiological culture of clinical specimens at Bac Ninh Provincial General Hospital in Bac Ninh Province, Vietnam.

Methods

We employed a cross-sectional analysis at Bac Ninh Provincial General Hospital in Vietnam. 15,232 clinical samples from inpatients were examined. S. aureus isolates were identified using established protocols and tested for MRSA and antibiotic susceptibility. Data was analyzed using R software, with statistical calculations to assess associations between variables.

Results

Staphylococcus aureus was isolated from 417 samples (2.7%), with 77.2% being MRSA and 22.8% methicillin-susceptible Staphylococcus aureus (MSSA). Significant sources of MRSA were wounds (64.6%) and the surgical unit (50%) according to sample types and hospital wards, respectively. S. aureus showed high resistance rates, the highest being azithromycin (83.2%), and was fully susceptible to vancomycin. Among 294 multidrug-resistant (MDR) strains, the prevalence was 82.0% in MRSA and 18.0% in MSSA.

Conclusion

The study highlights widespread antimicrobial resistance among MRSA isolates from a provincial hospital in Vietnam, emphasizing the urgent need for antibiotic surveillance, formulation of antibiotic policies, and preventive measures to tackle the increasing prevalence of multidrug-resistant MRSA.

Antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated at tertiary care hospital in Riyadh, Saudi Arabia

Staphylococcus aureus is an important human pathogen that has a major impact on public health. The objective of the present work was to determine the prevalence and the pattern of antibiotic susceptibility in S aureus (MRSA) isolates from the King Khalid University Hospital (KKUH) in Riyadh, Saudi Arabia. The isolates were collected from different body sites of infection and the antibiotic susceptibility was confirmed on the Vitek 2 system. A total of 371 MRSA isolates from clinical samples were received over a 12-month period from January 2021 to December 2021. The results showed that infection was predominant among males (55.8%) and most of the isolates occurred in the older age groups, with a mean age of 43.7 years and an age span from <1 to 89 years old. The majority (34.5%) recovered from wound infection followed by (14.6%) from blood. We have observed peaks of MRSA infections during the autumn, especially in September and November. All MRSA isolates were resistant to Amoxicillin + clavulanic acid, Ampicillin, Imipenem, Oxacillin, Cloxacillin, and Penicillin while all isolates were sensitive to Daptomycin and Nitrofurantoin. Furthermore, Vancomycin was resistant in (0.3%) of MRSA isolates, and (2.9%) was resistant to Linezolid. The current study concluded that MRSA strains had developed resistance toward 24 tested antibiotics, including the previous effective drugs vancomycin and linezolid. Therefore, there is an urgent need for continuous review of infection control practices to prevent any further spread of resistant strains.

Evaluation of In-Vitro Activity of Ceftaroline Against Methicillin-Resistant Staphylococcus aureus Clinical Isolates

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major causes of hospital and community-acquired infections. Fewer drugs, such as vancomycin, teicoplanin, and daptomycin, are effective against it, but they come with high toxicity. Fifth-generation cephalosporins like ceftaroline and second-generation cefuroxime are effective against MRSA. Limited studies are available on ceftaroline resistance in the literature. This study was undertaken to determine ceftaroline resistance in MRSA in a tertiary care hospital in Eastern India. A cross-sectional, hospital-based study was carried out with MRSA isolates obtained from various clinical samples of patients. Identification of the isolates to the species level was performed by an automated Vitek system, and selected samples were genotypically confirmed by detecting the mecA gene via real-time PCR. Out of a total of 334 Staphylococcus aureus isolates examined in this study, the prevalence of MRSA was seen in 59.3% (198/334), and methicillin-sensitive Staphylococcus aureus was in 40.7% (136/334). Of the total 198 MRSA isolates, ceftaroline intermediate MRSA was seen in 8.6% (17/198), and ceftaroline sensitive MRSA was in 91.4% (181/198), respectively. Among the 17 ceftaroline intermediate MRSA isolates, 88.2% (15/17) showed a minimum inhibitory concentration (MIC) of 2 µg/ml, and 11.8% (2/17) showed an MIC of 3 µg/ml. All the remaining 91.4% (181/198) isolates were sensitive to ceftaroline and showed an MIC ≤1 µg/ml. Real-time PCR confirmed the presence of the mecA gene in MRSA isolates. In this present study, not a single isolate was resistant to ceftaroline, suggesting that it, being a safer drug, can be used in place of glycopeptides such as vancomycin or teicoplanin and linezolid, where resistance has already been detected. The rational use of ceftaroline could be useful in clinical settings, and further studies will confirm the findings.

Prevalence, antimicrobial susceptibility pattern and multidrug resistance of methicillin-resistant Staphylococcus aureus isolated from clinical samples at a tertiary care teaching hospital: an observational, cross-sectional study from the Himalayan country, Nepal

OBJECTIVE

We sought to determine the prevalence and antimicrobial susceptibility pattern of methicillin-resistant Staphylococcus aureus (MRSA) isolated from the clinical samples at a tertiary care hospital in Nepal.

METHODS

Cross-sectional, observational study design.

STUDY SETTING

The study was carried out at a tertiary care facility, the largest public hospital, Tribhuvan University Teaching Hospital (TUTH), Nepal.

PARTICIPANTS

A total of 7433 clinical samples from hospital inpatients and outpatients available in the TUTH microbiology laboratory were examined. The study included clinical samples from the patients of either sex and across all age groups that had been clinically determined to have S. aureus infections.

RESULTS

Of 7433 clinical samples analysed, S. aureus was recovered from 499 (6.71%). The prevalence of MRSA was discovered to be 26.4% (95% CI 21.6% to 30.4%). The major sources of MRSA were pus, 71 (18.5%). MRSA isolates encountered 100% resistance to penicillin and cloxacillin, followed by ciprofloxacin (80.5%), erythromycin (79.8%), cephalexin (64.9%), cotrimoxazole (61.1%) and clindamycin (58.5%). Chloramphenicol (17.9%), and gentamicin (27.4%), on the other hand, exhibited minimal resistance. None of the isolates were resistant to vancomycin (0.0%). Prevalence of multidrug resistance (MDR) was markedly higher in MRSA, 94.05% (95% CI 89.4% to 98.6%), compared with methicillin-sensitive S. aureus, 52.12% (95% CI 46.2% to 57.8%).

CONCLUSION

Our study indicated a high rate of MRSA and MDR-SA (Multidrug-resistant Staphylococcus aureus) prevalence in a Nepalese tertiary care hospital. Therefore, given the widespread burden of MRSA and the threat of the emergence of resistance to commonly used antibiotics, there is a need for the development, adoption and enforcement of appropriate control policies in these hospital settings. Regular surveillance, reporting mechanism as well as prudent use of antimicrobial agents are crucial to combating the progression of MDR-MRSA prevalence and antibiotic resistance.

Effect of povidone-iodine and propanol-based mecetronium ethyl sulphate on antimicrobial resistance and virulence in Staphylococcus aureus

Background

Reports are available on cross-resistance between antibiotics and biocides. We evaluated the effect of povidone-iodine (PVP-I) and propanol-based mecetronium ethyl sulphate (PBM) on resistance development, antibiotics cross-resistance, and virulence in Staphylococcus aureus.

Methods

The minimum inhibitory concentration (MIC) of PVP-I and PBM were determined against S. aureus ATCC 25923 using the agar-dilution method. Staphylococcus aureus ATCC 25923 was subjected to subinhibitory concentrations of the tested biocides in ten consecutive passages followed by five passages in a biocide-free medium; MIC was determined after each passage and after the fifth passage in the biocide-free medium. The developed resistant mutant was tested for cross-resistance to different antibiotics using Kirby-Bauer disk diffusion method. Antibiotic susceptibility profiles as well as biocides’ MIC were determined for 97 clinical S. aureus isolates. Isolates were categorized into susceptible and resistant to the tested biocides based on MIC distribution pattern. The virulence of the biocide-resistant mutant and the effect of subinhibitory concentrations of biocides on virulence (biofilm formation, hemolysin activity, and expression of virulence-related genes) were tested.

Results

PVP-I and PBM MIC were 5000 μg/mL and 664 μg/mL. No resistance developed to PVP-I but a 128-fold increase in PBM MIC was recorded, by repeated exposure. The developed PBM-resistant mutant acquired resistance to penicillin, cefoxitin, and ciprofloxacin. No clinical isolates were PVP-I-resistant while 48.5% were PBM-resistant. PBM-resistant isolates were more significantly detected among multidrug-resistant isolates. PVP-I subinhibitory concentrations (¼ and ½ of MIC) completely inhibited biofilm formation and significantly reduced hemolysin activity (7% and 0.28%, respectively). However, subinhibitory concentrations of PBM caused moderate reduction in biofilm activity and non-significant reduction in hemolysin activity. The ½ MIC of PVP-I significantly reduced the expression of hla, ebps, eno, fib, icaA, and icaD genes. The virulence of the biocide-resistant mutant was similar to that of parent strain.

Conclusion

PVP-I is a highly recommended antiseptic for use in healthcare settings to control the evolution of high-risk clones. Exposure to PVP-I causes no resistance-development risk in S. aureus, with virulence inhibition by subinhibitory concentrations. Also, special protocols need to be followed during PBM use in hospitals to avoid the selection of resistant strains.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-022-01178-9.

Detection of Methicillin Resistance and β-Lactamase Production in Staphylococcus aureus Isolates: A Cross Sectional Study from a Tertiary Care Hospital

Nosocomial infections are proving to be a menace for the whole health care system, with methicillin resistant Staphylococcus aureus (MRSA) being a very notorious causative agent. Along with the role of mecA gene producing penicillin-binding protein (PBP2a), production of beta-lactamase enzyme by Staphylococcus aureus makes the organism resistant to all β-lactam agents. This study aims at phenotypic detection of methicillin resistance and β-Lactamase production in all S. aureus isolates by Cefoxitin disk diffusion test and Penicillin zone-edge test, respectively. In this prospective cross-sectional study, samples were obtained from patients admitted to different departments and were processed according to the standard laboratory protocols. As per the CLSI guidelines, phenotypic detection of resistance to methicillin was done by Cefoxitin Disk Diffusion test, whereas production of beta-lactamase enzyme was phenotypically detected by penicillin zone edge test. Among 179 isolates of S. aureus, 116 (64.8%) were MRSA, whereas the remaining 63 (35.2%) isolates were methicillin-sensitive Staphylococcus aureus (MSSA). Staphylococcus aureus infection among ICU and non-ICU patients were found to be 24(13%) and 155(86.6%) respectively. Among 24 ICU patients, 19 had MRSA infection, whereas among 155 non-ICU patients, 97 had MRSA infection. Out of 63 MSSA isolates, only 2 (3.17%) were found to be sensitive to Penicillin by Zone-edge test, 04 isolates showed presence of β-lactamase production, while remaining 57 isolates were resistant to Penicillin. At the same time, several class of antibiotics were found to be ineffective against these MRSA isolates. Cases of methicillin-resistant and b–lactamase producing Staphylococcus aureus infections are on the rise in our hospital settings.

Prevalence of enterotoxin genes (SEA to SEE) and antibacterial resistant pattern of Staphylococcus aureus isolated from clinical specimens in Assiut city of Egypt

Background

Infections in communities and hospitals are mostly caused by Staphylococcus aureus strains. This study aimed to determine the prevalence of five genes (SEA, SEB, SEC, SED and SEE) encoding staphylococcal enterotoxins in S. aureus isolates from various clinical specimens, as well as to assess the relationship of these isolates with antibiotic susceptibility. Traditional PCR was used to detect enterotoxin genes, and the ability of isolates expressing these genes was determined using Q.RT-PCR.

Results

Overall; 61.3% (n = 46) of the samples were positive for S. aureus out of 75 clinical specimens, including urine, abscess, wounds, and nasal swabs. The prevalence of antibiotic resistance showed S. aureus isolates were resistant to Nalidixic acid, Ampicillin and Amoxicillin (100%), Cefuroxime (94%), Ceftriaxone (89%), Ciprofloxacin (87%), Erythromycin and Ceftaxime (85%), Cephalexin and Clarithromycin (83%), Cefaclor (81%), Gentamicin (74%), Ofloxacin (72%), Chloramphenicol(59%), Amoxicillin/Clavulanic acid (54%), while all isolates sensitive to Imipinem (100%). By employing specific PCR, about 39.1% of isolates were harbored enterotoxin genes, enterotoxin A was the most predominant toxin in 32.6% of isolates, enterotoxin B with 4.3% of isolates and enterotoxin A and B were detected jointly in 2.1% of isolates, while enterotoxin C, D and E weren’t detected in any isolate.

Conclusion

This study revealed a high prevalence of S. aureus among clinical specimens. The isolates were also multidrug resistant to several tested antibiotics. Enterotoxin A was the most prevalent gene among isolates. The presence of antibiotic resistance and enterotoxin genes may facilitate the spread of S. aureus strains and pose a potential threat to public health.

Prevalence pattern of MRSA from a rural medical college of North India: A cause of concern

Introduction:

Methicillin-resistant Staphylococcus aureus (MRSA) has become a global challenge. The shift of this organism form hospital settings to community setting and increasing resistance to non-β-lactams antibiotics have further aggravated the crisis. This trend in MRSA has necessitated the knowledge and sensitization about this agent among physicians in rural and peripheral settings.

Material and Methods:

Present study was undertaken at Department of Microbiology at rural medical college of North India from January 2017 to December 2019 (3 years). All the clinical samples collected with aseptic precautions were processed as per standard protocol. All the Staphylococcus aureus isolates cultured were subjected to antimicrobial susceptibility testing as per CLSI guidelines 2019. Screening for MRSA was done by CLSI recommended methods, such as cefoxitin disc (30 μg), oxacillin disc (1 μg), and oxacillin screen agar as per CLSI recommendation.

Results:

A steady increase in number of MRSA isolates was observed from year 2017 to 2019 with overall prevalence being 33.7%. Most MRSA isolates were obtained from pus samples. Cefoxitin disc diffusion method is a dependable detection method compared to oxacillin disc diffusion and oxacillin screen agar for identification of MRSA.

Conclusion:

The rising trend of MRSA impresses upon the acute need of stringent infection control practices namely strict compliance to hand hygiene, prevention of misuse and overuse of antibiotics and a continuous surveillance program for MRSA. Also sensitization about this agent among the primary health physician is the need of hour to implement the control measures and limit its spread in communities.

Recent pattern of antibiotic resistance in Staphylococcus aureus clinical isolates in Eastern India and the emergence of reduced susceptibility to vancomycin

PURPOSE:

We aimed to determine the recent pattern of antibiotic resistance and assess the vancomycin susceptibility profile of clinical Staphylococcus aureus in view of emerging reports of vancomycin creep, reduced vancomycin susceptibility (RVS), including heterogeneous vancomycin-intermediate S. aureus (hVISA) and vancomycin-intermediate S. aureus, and vancomycin resistance in S. aureus isolates.

MATERIALS AND METHODS:

Consecutive, nonduplicate isolates of S. aureus between July 2015 and June 2016 were subjected to antimicrobial susceptibility testing using standard disk diffusion test or Etest as per the Clinical and Laboratory Standards Institute 2015. Detection of hVISA was done by glycopeptide resistance detection Etest according to the manufacturer's instructions in strains with vancomycin minimum inhibitory concentration of 1–2 μg/ml.

RESULTS:

A total of 284 S. aureus were obtained from pus (175, 61.6%), respiratory tract (31, 10.9%), urine (27, 9.5%), blood (25, 8.8%), body fluids (18, 6.3%), and catheter tips (8, 2.8%). 127 (44.7%) isolates were methicillin resistant, and 158 (55.6%) were multidrug resistant. High resistance was observed to penicillin (81.7%), erythromycin (62.3%), and ciprofloxacin (52.1%), whereas the resistance was low to gentamicin (5.3%), rifampicin (8.1%), and doxycycline (9.5%). Two hundred and fifty-one (88.3%) isolates were fully susceptible to vancomycin, whereas 33 (11.6%) demonstrated RVS. All were uniformly susceptible to linezolid, tigecycline, and daptomycin.

CONCLUSIONS:

A moderately high percentage of S. aureus isolates demonstrated RVS, which may limit its usefulness in methicillin-resistant isolates and may be associated with increased complications in methicillin-susceptible infections. In view of increasing glycopeptide resistance, the susceptibility status of vancomycin along with other antibiotics among clinical S. aureus isolates should be investigated periodically.

Evaluating the Bioactivity of a Novel Antimicrobial and Anticancer Peptide, Dermaseptin-PS4(Der-PS4), from the Skin Secretion of Phyllomedusa sauvagii

Dermaseptins belonging to a large family of cationic membrane-disruption antimicrobial peptides display extensive antibacterial and antiproliferative activities depending on a coil-to-helix transition and the specific structural parameters. Herein, a novel dermaseptin peptide named Der-PS4 was discovered from the skin secretion of the waxy monkey tree frog, Phyllomedusa sauvagii. The complementary DNA (cDNA)-encoding precursor was obtained relying on "shotgun" cloning, and afterwards, a mature peptide amino acid sequence was identified by reverse-phase high performance liquid chromatography (RP-HPLC) and MS/MS. Specimens were chemically synthesized and applied for further functional studies. Structural analysis demonstrated a higher α-helical content in the membrane-mimetic environment compared with that in the ammonium acetate/water circumstance. Der-PS4 displayed a broad spectrum of antimicrobial activities against tested pathogenic microorganisms, however, exhibiting slight membrane-damaging effectiveness towards horse red blood cells. Coincident with the inhibitory activities on pathogens, Der-PS4 also showed considerable biofilm eradicating impact. Also, Der-PS4 penetrated cell membrane in a relative short period under each minimum bactericidal concentration. In addition, Der-PS4 possessed antiproliferative capacity against five cancer cell lines, while presenting slight suppressing effect on human microvascular endothelial, HMEC-1. These findings provide a promising insight for the discovery and development of novel drugs from a natural source.

MRSA: the leading pathogen of orthopedic infection in a tertiary care hospital, South India

Background

The rate of infection is high and heterogeneous in developing countries. This study aimed to find the rate and pattern of infection in a tertiary care hospital with a goal to improve the infection control practices.

Methods

The study was conducted in the orthopedic units of a multispecialty teaching hospital. Medical records of major orthopedic surgery adult patients without immunosuppression state were included. The bacterial culture report of the wound swabs were noted over a period of one year. The bacterial culture testing was performed by a recommended method.

Results

Among 2,249 orthopedic surgery patients, 83.7% were males, 49.1% had open wounds during admission and 32.2% patients were infected. Majority (64.2%) of the injuries were in the lower limb with 19.4% patients having undergone multiple surgeries during hospitalization. A total of 946 pathogens were grown from 725 specimens. Staphylococcus aureus was the maximum (48.4%) followed by Pseudomonas aeruginosa (26.3%) and E coli (16.7%). Among them, 57.3% were Methicillin Resistant Staphylococcus aureus (MRSA) and was the leading pathogen causing infection among orthopedic patients.

Conclusion

MRSA infection was high. Consequent to this, an interventional program entitled ‘Extended Infection Control Measures' was designed to reduce the burden of infection.

Detection and molecular typing of methicillin-resistant Staphylococcus aureus from northeastern part of India

Background

In Staphylococcus aureus, methicillin resistance is exhibited by modifications in penicillin-binding protein that minimises the binding affinity to beta-lactam antibiotics. The present study investigated the occurrence of methicillin-resistant S. aureus (MRSA) in community-acquired infections, that is, community-acquired MRSA (CA-MRSA) and in-hospital-acquired infections, that is, hospital-acquired MRSA (HA-MRSA) from Northeast India.

Methods

A total of 197 consecutive non-duplicate isolates were collected from Silchar Medical College and Hospital and other private diagnostic laboratories. The isolates were confirmed to be S. aureus at our centre. All isolates were subjected to antibiotic susceptibility testing and were screened for methicillin resistance using cefoxitin disc test. All MRSA were subjected to Polymerase Chain Reaction (PCR) assay for detection of mecA and mecC genes. DNA fingerprinting was performed for determining clonal diversity.

Results

Seventy-one isolates of 127 confirmed S. aureus were found to be methicillin resistant by screening test. mecA gene was detected in 43 isolates, and none of the isolates were positive for mecC gene. Linezolid and teicoplanin showed better activity with susceptibility pattern being 83.6% and 72.44%, respectively, whereas 66.14% were sensitive to vancomycin. Other antibiotic showed low level of activity. Pulsed Field Gel Electrophoresis (PFGE) showed 14 different banding patterns that suggest isolates were of different clonal types.

Conclusion

mecA was responsible for methicillin resistance in majority of strains. Polyclonal spread of MRSA infection in the study area indicates its diverse origin and possible lateral transfer. Thus, this study is of clinical interest in terms of selection of proper antimicrobial chemotherapy and infection control management.

Molecular characterisation of Staphylococcus aureus using spa typing as a diagnostic tool in Haryana, India

Background

Staphylococcus aureus is one of the top six most common etiologic agents of nosocomial, community and livestock acquired bacterial infections. These infections although initially were described as a major problem in hospitals have now also become a serious threat in community not only in India but also worldwide. Its prevalence varies depending on the health-care setting, country or a particular region. Thus to better understand the epidemiology of methicillin-resistant S. aureus (MRSA) in a particular geographical location, it is important to study the variations in the population using molecular tools.

Methods

This prospective study was carried out in the Department of Microbiology of Shree Guru Gobind Singh Tricentenary (SGT) Medical College. Staphylococcal protein A (spa) typing was done on 250 S. aureus isolates obtained from various clinical specimens including pus, wound swabs, urine, catheters, blood and cerebrosspinal fluid from both indoor and outdoor patients of SGT Hospital, Budhera, Gurgaon.

Results

The selected region of the spa gene of all 250 isolates which includes 87 MRSA and 163 methicillin-susceptible S. aureus were amplified. The spa gene was detected in 248 out of 250 isolates (99.2%), whereas in 2 isolates (0.8%), it remained undetected and referred as non-typable isolates. The 248 S. aureus isolates were typed into 39 spa types, which clustered into six different spa clonal clusters and eight singletons.

Conclusion

High diversity observed within S. aureus isolates indicated that many different strains circulate in the study region or in the hospital. The results would contribute in the understanding of epidemiology related to S. aureus spread and prevention.

A novel templates of piperazinyl-1,2-dihydroquinoline-3-carboxylates: Synthesis, anti-microbial evaluation and molecular docking studies

A series of piperazinyl-1,2-dihydroquinoline carboxylates were synthesized by the reaction of ethyl 4-chloro-1-methyl-2-oxo-1,2-dihydroquinoline-3-carboxylates with various piperazines and their structures were confirmed by ¹H NMR, ¹³C NMR, IR and mass spectral analysis. All the synthesized compounds were screened for their in vitro antimicrobial activities. Further, the in silico molecular docking studies of the active compounds was performed to explore the binding interactions between piperazinyl-1,2-dihydroquinoline carboxylate derivatives and the active site of the Staphylococcus aureus (CrtM) dehydrosqualene synthase (PDB ID: 2ZCQ). The docking studies revealed that the synthesized derivatives showed high binding energies and strong H-bond interactions with the dehydrosqualene synthase validating the observed antimicrobial activity data. Based on antimicrobial activity and docking studies, the compounds 9b and 10c were identified as promising antimicrobial lead molecules. This study might provide insights to identify new drug candidates that target the S. aureus virulence factor, dehydrosqualene synthase.

Detection of high levels of resistance to linezolid and vancomycin in Staphylococcus aureus

Both methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) are rapidly overcoming the current array of drugs. One hundred and fifty isolates from a hospital were studied for resistance towards linezolid and vancomycin. Fifty-four (36.0 %) isolates were MRSA. Both MRSA and MSSA showed high resistance towards linezolid when using the disc diffusion method, with the figures being 48.1 and 29.2 %, respectively. The figures for the E-test were 46.3 and 27.0 %, respectively. The vancomycin resistance was remarkable in MRSA (14.8 %), but relatively low in MSSA (3.1 %). The E-test results were 13.0 and 4.16 %, respectively. The cfr gene was detected in 78 % of linezolid-resistant isolates and the vanA operon was detected in 74 % of vancomycin-resistant isolates. This level of resistance against linezolid and vancomycin is unprecedented. These results are alarming and highlight the threat of non-treatable S. aureus strains.

Penicillin dust exposure and penicillin resistance among pharmaceutical workers in Tehran, Iran

BACKGROUND

Antimicrobial resistance (AMR) adversely impacts the prevention and treatment of a wide range of infections and is considered as a serious threat to global public health. Occupational-related AMR is a neglected area of research.

OBJECTIVE

To assess exposure to penicillin dust, penicillin active materials, and to report the frequency of penicillin resistance among pharmaceutical workers in Tehran, Iran.

METHODS

A quasi-experimental study was conducted among workers on a penicillin production line in a pharmaceutical company (n = 60) and workers in a food producing company (n = 60). Data were collected via survey, air sampling, and throat swab.

RESULTS

The mean overall concentrations of penicillin dust and penicillin active material were 6.6 and 4.3 mg/m³, respectively, in the pharmaceutical industry. Streptococcus pneumoniae (S. pneumoniae) was detected in 45% (27) individuals in the exposed group, 92.6% of which showed penicillin resistance. Resistance was significantly higher among workers in penicillin production line (p = 0.014).

CONCLUSIONS

High level of AMR among workers in penicillin production line is a health risk for the workers as well as society as a whole through the spread of drug resistant micro-organisms.

High frequency of methicillin-resistant Staphylococcus aureus in Peshawar Region of Pakistan

Staphylococcus aureus is an increasing problem in clinical practice because of reduced susceptibility to available antibiotics. The objective of the study was to determine the frequency of Methicillin-resistant S. aureus (MRSA) in Peshawar, Pakistan. Clinical isolates of S. aureus were subjected to determination of antibiotic resistance, MICs and inducible clindamycin resistance (ICR). Out of total 280 S. aureus isolates, the frequency of MRSA was 36.1 % (n = 101). MRSA infection was found higher among the age group 50-59 years (60.71 %, OR 3.09), followed by 20-29 years (47.5 %, OR 1.74). Frequency of MRSA in female and male was 39.8 and 34 % respectively. MRSA was more frequent in blood specimens (48.7 %, OR 2.14). The frequency of community and hospital acquired MRSA was 42 and 34.8 % respectively. MRSA showed high resistance (100 %) to penicillin and cefoxitin followed by erythromycin (99 %). While MRSA exhibited 100 % susceptibility to vancomycin and linezolid. We have also found 7 vancomycin intermediate sensitive S. aureus (VISA) isolates. ICR was observed in 15.84 % (n = 16) of MRSA isolates. It is concluded that MRSA is potential threat to public health in Peshawar. Vancomycin and linezolid could be prescribed as a drug of choice in treating MRSA associated infections. In addition, ICR should be routinely checked to avoid clindamycin treatment failure.

Resistant Strains of Enterotoxigenic Staphylococcus aureus; Unknown Risk for Multiple Sclerosis Exacerbation

Background:

Despite all advances in neurological sciences, there are unknown aspects in the epidemiology of multiple sclerosis (MS). Based on this hypothesis, the enterotoxigenic strains of Staphylococcus aureus (S. aureus) are possible risk factors for exacerbations of MS.

Objectives:

The present study was carried out to investigate the role of resistant strains of enterotoxigenic S. aureus in MS exacerbation.

Materials and Methods:

Two-hundred nasal swab samples were collected from non-MS (n = 80), MS stable (n = 60) and MS exacerbation (n = 60) groups. Samples were cultured and those that were S. aureus-positive were analyzed for the presence of enterotoxins, using polymerase chain reaction (PCR). Antimicrobial susceptibility was performed using disk diffusion method.

Results:

Ninety out of 200 nasal samples (45%) were positive for S. aureus. The highest levels of nasal colonization were seen in MS exacerbation group (68.33%). The most commonly detected enterotoxins were sea (30%), sec (15.55%) and seb (11.11%). There were significant differences between S. aureus colonization and type of samples (P = 0.026) and, also, between type of samples and prevalence of enterotoxins (P = 0.022). The highest levels of enterotoxigenic genes were seen in MS exacerbation group. The S. aureus strains had the highest levels of resistance against tetracycline (80%), ampicillin (72.22%), methicillin (66.66%), erythromycin (66.66%), oxacillin (63.33%), trimethoprim-sulfamethoxazole (61.11%) and cotrimoxazole (55.55%).

Conclusions:

Our findings should raise awareness about the role of sea and sec enterotoxins, in resistant strains of S. aureus, as a risk factor for MS exacerbation. It is better to keep MS patients away from polluted environments of hospitals and health centers.

Evaluation of Multidrug Resistant Staphylococcus aureus and their Association with Biofilm Production in a Tertiary Care Hospital, Tripura, Northeast India

BACKGROUND

High morbidity and mortality rates are associated with Methicillin-resistant Staphylococcus aureus (MRSA) because of development of multidrug resistance. Staphylococcus aureus (S. aureus) has the ability to colonize and form biofilms on biomaterials which is causing resistance towards antimicrobials and thus making them difficult to eradicate from the infected hosts.

MATERIALS AND METHODS

Culture isolation, identification was done following standard protocol and antibiogram of the isolates were done. The detection of MRSA, Macrolide-Lincosamide-Streptogramin B resistance (MLSB), vancomycin resistance phenotypes were done by using cefoxitin disc diffusion test, D zone test and vancomycin E test. Biofilm was detected by Congo red agar method.

RESULTS

A total of 100 (31.7%) S. aureus strains were isolated from 315 clinical specimens. The prevalence of MRSA was 47% (47/100) with 85.1% were homogeneous MRSA and 14.9% were heterogeneous. Out of 47 MRSA strains, 63.8% were Hospital acquired-MRSA (HA-MRSA) infections whereas rests 36.2% were caused by Community acquired-MRSA (CA-MRSA) strains. Maximum number of MRSA isolates belonged to group A biotype (34%). A 14.9% isolates were of nontypeable group. Out of 100 S. aureus isolates, the prevalence of Vancomycin resistant S. aureus (VRSA) was found to be 3%. The MLSB phenotypes showed that the rates of inducible MLSB (iMLSB), constitutive MLSB (cMLSB) and Macrolide-Streptogramin B (MSB) in case of MRSA to be 19.1%, 31.9% and 12.8%. Prevalence of low-level (MUP(L)) and high-level mupirocin resistance (MUP(H)) among MRSA was 19.1% and 6.4%. Biofilm production was found in 55% strains of S. aureus. Out of 47 MRSA strains 76.6%were producing biofilm in comparison to 38.8% in methicillin-sensitive S. aureus (MSSA). Higher degree of antibiotic resistance in biofilm producers was seen especially in case of ciprofloxacin, co-trimoxazole, rifampicin, kanamycin, erythromycin and clindamycin whereas gentamycin, tetracycline and penicillin resistance was more in non-biofilm producers.

CONCLUSION

This study shows high rate of circulating MRSA with a majority of these isolates are multi-drug resistant of which mostly are biofilm producers in our hospital setup. Development of antimicrobial stewardship program based on the local epidemiological data and national guidelines is the need of the hour.

Clinical and Antibacterial Efficacy and Safety of Besifloxacin Ophthalmic Suspension Compared With Moxifloxacin Ophthalmic Solution

PURPOSE

To evaluate the efficacy of besifloxacin ophthalmic suspension 0.6% compared with moxifloxacin ophthalmic solution 0.5% in the treatment of bacterial conjunctivitis in an Indian population.

DESIGN

Multicenter, randomized, double-masked, active-controlled, parallel-group, clinical trial, including 6 clinical sites in India.

METHODS

Patients were randomized to receive 1 drop of besifloxacin or moxifloxacin in the infected eye(s), 3 times daily, for 5 days. Primary efficacy end points included clinical resolution and bacterial eradication at day 5. Secondary efficacy end points included clinical resolution and bacterial eradication at day 8, ocular discharge, bulbar conjunctival injection, investigator's global assessment, and bacterial eradication by species. Efficacy was analyzed using the Cochran-Mantel-Haenszel and Pearson χ2 tests. Safety was assessed by the incidence of ocular and nonocular treatment-emergent adverse events (AEs), changes in visual acuity, and biomicroscopy and ophthalmoscopy findings. Data presented are that for the subset of patients from India.

RESULTS

Of the 123 patients randomized at clinical sites in India, 96.7% completed the study. Day 5 differences in microbial eradication (100% besifloxacin vs 96.3% moxifloxacin) and in clinical resolution (78.9% besifloxacin vs 71.4% moxifloxacin) were not statistically significant. No statistically significant between-group differences were observed for secondary end points. All ocular AEs in both groups were mild or moderate in severity. There were no drug-related ocular AEs with besifloxacin.

CONCLUSIONS

Treatment of bacterial conjunctivitis with besifloxacin 0.6% produces similar antibacterial and clinical efficacy as that with moxifloxacin 0.5% in an Indian population, with no clinically meaningful safety concerns.

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

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.

Could chloramphenicol be used against ESKAPE pathogens? A review of in vitro data in the literature from the 21st century

The widespread use of antibiotics has been associated with the emergence of antimicrobial resistance among bacteria. 'ESKAPE' (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acintobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) pathogens play a major role in the rapidly changing scenario of antimicrobial resistance in the 21st century. Chloramphenicol is a broad spectrum antibiotic that was abandoned in developed countries due to its association with fatal aplastic anemia. However, it is still widely used in the developing world. In light of the emerging problem of multi-drug resistant pathogens, its role should be reassessed. Our paper reviews in vitro data on the activity of chloramphenicol against ESKAPE pathogens. Susceptibility patterns for Gram-positives were good, although less favorable for Gram-negatives. However, in combination with colistin, chloramphenicol was found to have synergistic activity. The risk-benefit related to chloramphenicol toxicity has not been analyzed. Therefore, extra precautions should be taken when prescribing this agent.

Nosocomial Infections and Drug Susceptibility Patterns in Methicillin Sensitive and Methicillin Resistant Staphylococcus aureus

AIM

Staphylococcus aureus is one of the leading causes of nosocomial infections and is known for its ability to develop resistance to antibiotics. The drug susceptibility pattern of Methicillin Sensitive S. aureus (MSSA) and Methicillin Resistant S. aureus (MRSA) may vary. AIMs and Objectives: This study was carried out to determine and compare the drug susceptibility patterns in nosocomial MSSA and MRSA.

MATERIAL AND METHODS

The study was conducted between September 2009 and August 2011. Standard conventional methods were used for the isolation and identification of S. aureus. MRSA was identified by the cefoxitin (30 μg) disk method. Antibiotic susceptibility test was done using Kirby-Bauer disk diffusion method and the interpretation of the results was done using CLSI guidelines.

RESULTS

Out of 685 strains of S. aureus studied, 173(25.25%) were MRSA and 512 (74.25%) were MSSA. Out of 173 MRSA strains, 114(65.89%) were isolated from pus, 22(12.71%) from vaginal swab, 18(10.40%) from central catheter tip and the remaining from other specimens. All isolates were susceptible to vancomycin and least number of isolates were susceptible to penicillin. MRSA displayed significantly higher resistance to other antibiotics. 45.7% of MRSA strains were resistant to clindamycin, 64.7% to ciprofloxacin, 87.3% to cotrimoxazole, 54.3% to erythromycin, 17.3% to gentamicin, 16.8% to netilmycin, and 58.38% to tetracycline. Inducible clindamycin resistance was detected in 37 (21.38%) strains of MRSA.

CONCLUSION

Nosocomial infections caused by MRSA is a significant problem. MRSA and MSSA differ with their susceptibility to antibiotics. All MRSA isolates in our hospitals were susceptible to vancomycin. Proper selection of the antibiotics based on antibiotic susceptibility test results is needed for effective treatment and prevention of emergence of resistance in MRSA and MSSA.

Combination of alpha-melanocyte stimulating hormone with conventional antibiotics against methicillin resistant Staphylococcus aureus

Our previous studies revealed that alpha-melanocyte stimulating hormone (α-MSH) is strongly active against Staphylococcus aureus (S. aureus) including methicillin resistant S. aureus (MRSA). Killing due to α-MSH occurred by perturbation of the bacterial membrane. In the present study, we investigated the in vitro synergistic potential of α-MSH with five selected conventional antibiotics viz., oxacillin (OX), ciprofloxacin (CF), tetracycline (TC), gentamicin (GM) and rifampicin (RF) against a clinical MRSA strain which carried a type III staphylococcal cassette chromosome mec (SCCmec) element and belonged to the sequence type (ST) 239. The strain was found to be highly resistant to OX (minimum inhibitory concentration (MIC) = 1024 µg/ml) as well as to other selected antimicrobial agents including α-MSH. The possibility of the existence of intracellular target sites of α-MSH was evaluated by examining the DNA, RNA and protein synthesis pathways. We observed a synergistic potential of α-MSH with GM, CF and TC. Remarkably, the supplementation of α-MSH with GM, CF and TC resulted in ≥64-, 8- and 4-fold reductions in their minimum bactericidal concentrations (MBCs), respectively. Apart from membrane perturbation, in this study we found that α-MSH inhibited ∼53% and ∼47% DNA and protein synthesis, respectively, but not RNA synthesis. Thus, the mechanistic analogy between α-MSH and CF or GM or TC appears to be the reason for the observed synergy between them. In contrast, α-MSH did not act synergistically with RF which may be due to its inability to inhibit RNA synthesis (<10%). Nevertheless, the combination of α-MSH with RF and OX showed an enhanced killing by ∼45% and ∼70%, respectively, perhaps due to the membrane disrupting properties of α-MSH. The synergistic activity of α-MSH with antibiotics is encouraging, and promises to restore the lost potency of discarded antibiotics.

Community-associated, methicillin-susceptible, and methicillin-resistant Staphylococcus aureus bone and joint infections in children: experience from India

Previously, the treatment of Staphylococcus aureus infections was less complex, as most of those isolated were susceptible to β-lactam antibiotics. In recent years, there has been a marked increase in the incidence of invasive community-acquired (CA) methicillin-resistant S. aureus (MRSA) among children worldwide. However, data on the clinical characteristics and outcomes related to pediatric bone and joint infections caused by CA-S. aureus are very limited in India. In this tertiary hospital-based study, 74 patients with invasive S. aureus less than 18 years of age were identified between January 2004 and December 2008. All patients fulfilled the case definition of CA-S. aureus with evidence of infection before admission; they presented to our hospital without previous antibiotic use and were culture positive for S. aureus within 48 h of admission. All data including demographics, clinical features, treatment protocol, laboratory findings, and antimicrobial susceptibilities were recorded and compared using the SPSS 11.5 statistical software. Of the 74 patients with culture-positive S. aureus bone and joint infection, 41 had MRSA (55%). Forty-nine patients (66.2%) had osteomyelitis, of whom 29 (59.18%) had MRSA and 25 (33.7%) had septic arthritis, of whom 12 (48%) had MRSA. The MRSA group had a significantly higher erythrocyte sedimentation rate, C-reactive protein value, neutrophil count, and white blood cell count (P<0.05). The MRSA group also had longer duration of febrile days, hospital stay, and antibiotic course compared with the methicillin-susceptible S. aureus (MSSA) group (P<0.05). A clinical predictive algorithm was developed using seven significant independent multivariate predictors, with the probability of MRSA being 94% if all seven predictors were positive and 9% if five predictors were positive. Resistance to many classes of antibiotics was noted among S. aureus isolates including trimethoprim-sulfamethoxazole (MRSA 80%, MSSA 24%), erythromycin (MRSA 83%, MSSA 67%), clindamycin (MRSA 54%, MSSA 34%), and ciprofloxacin (MRSA 61%, MSSA 48%). No vancomycin resistance was observed. The morbidity associated with MRSA bone and joint infection in children is significantly higher than that caused by MSSA. Early diagnosis at the primary healthcare level and treatment with appropriate antistaphylococcal therapy are crucial to achieve optimal clinical outcomes. High levels of antimicrobial resistance of both MSSA and MRSA isolates to several classes of antibiotics are a major concern warranting the need for antimicrobial stewardship and ongoing surveillance.

Rationalizing antibiotic use to limit antibiotic resistance in India

Antibiotic resistance, a global concern, is particularly pressing in developing nations, including India, where the burden of infectious disease is high and healthcare spending is low. The Global Antibiotic Resistance Partnership (GARP) was established to develop actionable policy recommendations specifically relevant to low- and middle-income countries where suboptimal access to antibiotics - not a major concern in high-income countries - is possibly as severe a problem as is the spread of resistant organisms. This report summarizes the situation as it is known regarding antibiotic use and growing resistance in India and recommends short and long term actions. Recommendations aim at (i) reducing the need for antibiotics; (ii) lowering resistance-enhancing drug pressure through improved antibiotic targeting, and (iii) eliminating antibiotic use for growth promotion in agriculture. The highest priority needs to be given to (i) national surveillance of antibiotic resistance and antibiotic use - better information to underpin decisions on standard treatment guidelines, education and other actions, as well as to monitor changes over time; (ii) increasing the use of diagnostic tests, which necessitates behavioural changes and improvements in microbiology laboratory capacity; (iii) setting up and/or strengthening infection control committees in hospitals; and (iv) restricting the use of antibiotics for non-therapeutic uses in agriculture. These interventions should help to reduce the spread of antibiotic resistance, improve public health directly, benefit the populace and reduce pressure on the healthcare system. Finally, increasing the types and coverage of childhood vaccines offered by the government would reduce the disease burden enormously and spare antibiotics.

Prevalence and Antimicrobial Susceptibility Pattern of Methicillin-resistant Staphylococcus Aureus [MRSA] Isolates at a Tertiary Care Hospital in Mangalore, South India

Background/Aim:

Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of nosocomial infections worldwide. The aim of this study was to determine the prevalence of MRSA and their antimicrobial susceptibility pattern in our hospital located in Mangalore, India.

Materials and Methods:

The bacterial isolates from various clinical specimens of patients admitted in our hospital were cultured as per standard protocol and all isolates of Staphylococcus aureus obtained were included in the study. The isolates were identified by standard methods like catalase test, slide and tube coagulase tests, and growth on Mannitol salt agar (HiMedia Lab, Mumbai). The antimicrobial susceptibility testing was performed by Kirby–Bauer disc diffusion method. The D-test for inducible clindamycin resistance was performed. The isolates were tested for methicillin resistance by using oxacillin disc by disc diffusion method and confirmed by agar screen test (oxacillin 6 μgm/ml). The results were interpreted according to CLSI criteria.

Results:

During a period of one year, a total of 237 isolates of S. aureus were studied and 69 (29.1%) were found to be methicillin-resistant. MRSA isolates showed greater resistance to multiple drugs than methicillin sensitive Staphylococcus aureus MSSA isolates. Inducible clindamycin resistance was 18.8% in MRSA as against 3.5% in MSSA. About 40–50% of MRSA were resistant to erythromycin, gentamicin, and chloramphenicol, while less than 30% were resistant to ciprofloxacin and amikacin. However, all strains were sensitive to vancomycin.

Conclusion:

The regular surveillance of hospital-acquired infections of MRSA may be helpful in formulating and monitoring the antibiotic policy. This may also help in preserving antibiotics like vancomycin, only for life-threatening staphylococcal diseases.

Nasal carriage of multi-drug resistant Staphylococcus aureus in healthy inhabitants of Amassoma in Niger delta region of Nigeria

BACKGROUND

Nasal Staphylococcus aureus is a major source of community and hospital associated staphylococcal infections. This study determined the prevalence of nasal S. aureus isolates and investigated their antimicrobial resistance profile in healthy volunteers.

METHODS

Nasal specimens of healthy volunteers in Amassoma were cultured and screened for S. aureus using standard microbiological protocols and their antibiotic profile susceptibility was investigated using disc diffusion and agar dilution techniques.

RESULTS

A total of 40 (33.3%) S. aureus isolates were obtained from 120 nares specimens screened. Twenty three (57.5%) and 17 (42.5%) of the isolates were from university students and villagers respectively. The isolates showed an overall 75% resistance to ampicillin, 52.5% to doxycycline, 47.5% to chloramphenicol, 35% to erythromycin and 32.5% to cotrimoxazole; with 27.5% methicillin resistant. No isolate was resistant to gentamicin while few isolates were resistant to cefuroxime (2.5%), augmentin (5.0%), ciprofloxacin (10.0%), ofloxacin (10.0%) and vancomycin (7.5%). Twenty one (52.5%) of all the isolates were multi-drug resistant, ten (47.6%) of which were methicillin resistant Staphylococcus aureus (MRSA) and only 3 (7.5%) were fully susceptible to all the tested antimicrobial drugs.

CONCLUSIONS

The observation calls for strategies to prevent their spread to more vulnerable populations where the consequences of their infections can be severe.