A Systemic Literature Review and Meta-Analysis Reporting the Prevalence and Impact of Methicillin-Resistant Staphylococcus aureus Infection in India

Preparation and optimization of niosome encapsulated meropenem for significant antibacterial and anti-biofilm activity against methicillin-resistant Staphylococcus aureus isolates

Background

One of the targeted drug delivery systems is the use of nanocarriers, and one of these drug delivery systems is niosome. Niosome have a nano-vesicular structure and are composed of non-ionic surfactants. Objective: In this study, various niosome-encapsulated meropenem formulations were prepared. Subsequently, their antibacterial and anti-biofilm activities were evaluated against methicillin-resistant Staphylococcus aureus (MRSA) strains.

Methods

The physicochemical properties of niosomal formulations were characterized using a field scanning electron microscope, X-Ray diffraction, Zeta potential, and dynamic light scattering. Antibacterial and anti-biofilm activities were evaluated using broth microdilution and minimum biofilm inhibitory concentration, respectively. In addition, biofilm gene expression analysis was performed using quantitative Real-Time PCR. To evaluate biocompatibility, the cytotoxicity of niosome-encapsulated meropenem in a normal human diploid fibroblast (HDF) cell line was investigated using an MTT assay.

Results

An F1 formulation of niosome-encapsulated meropenem with a size of 51.3 ± 5.84 nm and an encapsulation efficiency of 84.86 ± 3.14 % was achieved. The synthesized niosomes prevented biofilm capacity with a biofilm growth inhibition index of 69 % and significantly downregulated icaD, FnbA, Ebps, and Bap gene expression in MRSA strains (p < 0.05). In addition, the F1 formulation increased antibacterial activity by 4-6 times compared with free meropenem. Interestingly, the F1 formulation of niosome-encapsulated meropenem indicated cell viability >90 % at all tested concentrations against normal HDF cells. The results of the present study indicate that niosome-encapsulated meropenem increased antibacterial and anti-biofilm activities without profound cytotoxicity in normal human cells, which could prove useful as a good drug delivery system.

Community-acquired multidrug-resistant pneumonia, bacteraemia, and infective endocarditis: A case report

BACKGROUND

The prevalence of multidrug-resistant (MDR) bacteria has increased globally, with extensive drug-resistant (XDR) bacteria posing a threat to patients.

CASE SUMMARY

This case report describes a young man admitted for suspected tropical fever infections who experienced rapid deterioration in health. Despite negative results for tropical fever infections, he had neutrophilic leucocytosis, acute kidney injury, and chest imaging findings suggestive of bilateral consolidations. On day two, he was diagnosed with infective endocarditis with possible rheumatic heart disease and MDR methicillin-resistant Staphylococcus aureus bacteraemia, and community-acquired pneumonia. Despite treatment with broad-spectrum antibiotics, he did not respond and succumbed to death on day five.

CONCLUSION

This case highlights that clinicians/public should be aware of MDR community-acquired pneumonia, bacteraemia, and endocarditis which ultimately culminate in high rates of morbidity and mortality. Early identification of pathogenic strain and prompt antibiotic treatment are a mainstay for the management and prevention of early fatalities. Simultaneously, route cause analysis of community-acquired MDR/XDR pathogens is a global need.

Efficacy and Safety of Oral and IV Levonadifloxacin Therapy in Management of Bacterial Infections: Findings of a Prospective, Observational, Multi-center, Post-marketing Surveillance Study

Background Antimicrobial resistance by bacteria poses a substantial threat to morbidity and mortality worldwide, and treatment of resistant infections is a challenge for the treating clinician. Levonadifloxacin is a novel broad-spectrum agent belonging to the benzoquinolizine subclass of quinolone, which can be used by both oral and intravenous administration for the treatment of infections caused by gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA). Patients and methods This prescription event monitoring study captured data from 1266 patients receiving levonadifloxacin (oral and/or IV) in a real-world setting to assess the safety and efficacy in the treatment of various bacterial infections. The duration of the study was 18 months. Study outcomes were clinical success and microbial success at the end of therapy. Global assessments were done for safety and efficacy at the end of therapy using a 5-point Likert scale (excellent, very good, good, satisfactory, and poor). Results The mean (median) duration of therapy was 7.2 (7.0) days, with a median time to clinical improvement of four days. Oral therapy was administered to 224 patients; 940 received IV, and 102 received IV followed by oral therapy. Patients were prescribed levonadifloxacin for gram-positive infections, skin and soft tissue infections, diabetic foot infections, septicemia, catheter-related blood-stream infections, bone and joint infections, febrile neutropenia, and respiratory infections, including COVID-19 pneumonia. The clinical cure on the eighth day was 95.7%, whereas the microbial success on the eighth day was 93.3% (n=60). For different types of infections, the clinical success rates ranged from 85.2% to 100%. There were only 30 treatment-emergent adverse events reported in 29 patients. Overall, about 95.6% of patients rated the efficacy as good to excellent, whereas only 3.8% of patients rated it satisfactory; for safety, 95.7% of patients rated it as good to excellent, with only 3.9% of patients rated it as satisfactory. Conclusions The excellent safety and efficacy profile of levonadifloxacin, when administered as an oral or intravenous therapy, makes it a desirable treatment modality for the management of various bacterial infections, including those caused by resistant pathogens such as MRSA and quinolone-resistant Staphylococcus aureus (QRSA). Features of levonadifloxacin, such as availability in both IV and oral form, minimal drug-drug interactions, lack of the need to adjust dosages in renal and hepatically impaired patients along with a broad spectrum of coverage, make it a suitable agent that meets several unmet clinical needs of physicians.

Decrease in vancomycin MICs and prevalence of hGISA in MRSA and MSSA isolates from a German pediatric tertiary care center

PURPOSE

Resistance of Staphylococcus aureus to vancomycin includes a general increase of minimal inhibitory concentrations (MIC) within the susceptible range over time (Vancomycin MIC Creep) and the presence of a subset of the bacterial population that expresses resistance (heterogeneous glycopeptide-intermediate S. aureus; hGISA). Increased MICs have been associated with adverse clinical outcomes. However, the vancomycin MIC creep is not a uniform trend suggesting the importance of regional surveys.

METHODS

We performed a retrospective analysis at a German pediatric tertiary care hospital. Isolates from 2002 to 2017 were selected which were newly identified methicillin-resistant S. aureus (MRSA) or samples from invasive methicillin-susceptible S. aureus (MSSA) or MRSA infections. Vancomycin and oxacillin MICs as well as GISA/hGISA were measured using MIC test strips and resistance was evaluated over time.

RESULTS

A total of 540 samples were tested, 200 from the early (2002-2009) and 340 from the later period (2010-2017). All samples were vancomycin susceptible, but the MIC was higher for the earlier samples as compared to the later ones (1.11 vs 0.99; p < 0.001). 14% of the samples were hGISA, GISA strains were not detected. Again, vancomycin resistance decreased over time with 28 vs. 6% hGISA (p < 0.001). There was no significant difference between MRSA and MSSA samples with respect to vancomycin MIC and hGISA prevalence.

CONCLUSION

This study shows a decreasing trend for both MIC values and presence of hGISA strains highlighting the importance of monitoring local susceptibilities. Vancomycin remains a first-line treatment option for suspected severe infection with Gram-positive cocci and proven infection with MRSA.

Real-World Evidence of Efficacy and Safety of Levonadifloxacin (Oral and IV) in the Management of Acute Bacterial Skin and Skin Structure Infections (ABSSSI): Findings of a Retrospective, Multi-Center Study

Background

Antimicrobial resistance by bacteria poses a substantial threat to the success in the treatment of acute bacterial skin and skin structure infections (ABSSSI). Levonadifloxacin is a novel benzoquinolizine subclass of quinolone which has a broad spectrum of activity, available in both oral and intravenous formulations for the treatment of skin structure infections caused by Gram-positive pathogens including methicillin-resistant Staphylococcus aureus (MRSA).

Patients and methods

This prescription event monitoring study captured data of 227 patients receiving levonadifloxacin (oral and/or IV) in a real-world setting to assess the safety and efficacy in the treatment of ABSSSI. Study outcomes were a clinical and microbial success at the end of therapy and safety was assessed based on adverse events reported.

Results

One hundred and forty patients received IV levonadifloxacin therapy, 76 patients received oral alalevonadifloxacin, and 11 received IV followed by oral therapy. The mean duration of therapy was 7.3 days. Out of 227 patients, MRSA isolates were identified in 79 patients. Clinical success rates with oral, IV, and IV followed by oral levonadifloxacin therapy were 97.3%, 97.8%, and 100% respectively. The overall microbial success rate was 99.2% and only two patients reported two adverse events.

Conclusions

The excellent safety and efficacy profile of levonadifloxacin on oral and/or intravenous therapy, makes it a desirable treatment modality for management of ABSSSI. Unique features of levonadifloxacin such as availability of both IV and oral form, minimal drug-drug interactions, exemption from dosage adjustment in renal and hepatic impaired patients and a broad spectrum of coverage, makes it a suitable agent meeting several unmet clinical needs in contemporary patients.

Molecular Confirmation of Vancomycin-Resistant Staphylococcus aureus with vanA Gene from a Hospital in Kathmandu

Staphylococcus aureus, a commensal on the skin and in the nasal cavity of humans, is one of the most serious cases of nosocomial infections. Moreover, methicillin-resistant S. aureus (MRSA) is a leading cause of morbidity and mortality worldwide. For the treatment of MRSA infections, vancomycin is considered as a drug of choice. However, the emergence of vancomycin resistance among MRSA isolates has been perceived as a formidable threat in therapeutic management. To estimate the rate of vancomycin-resistant S. aureus (VRSA) and to detect the vancomycin-resistant genes, namely, vanA and vanB, among the isolates, a hospital-based cross-sectional study was conducted from July to December 2018 in Annapurna Neurological Institute and Allied Science, Kathmandu, Nepal. S. aureus was isolated and identified from different clinical samples and processed for antibiotic susceptibility testing by the modified Kirby-Bauer disc diffusion method. The screening of MRSA was performed as per Clinical and Laboratory Standard Institute (CLSI) guidelines. VRSA was confirmed by the minimum inhibitory concentration (MIC) method by employing E-test strips. All the phenotypically confirmed VRSA were further processed to detect the vanA and vanB gene by using the conventional polymerase chain reaction (PCR) method. A total of 74 (20.3%) S. aureus were isolated, and the highest percentage of S. aureus was from the wound samples (36.5%). Of 74 S. aureus isolates, the highest number (89.2%) was resistant to penicillin, and on the other hand, linezolid was found to be an effective drug. Likewise, 45 (60.81%) were found to be MRSA, five (11.11%) were VRSA, and 93.2% of S. aureus isolates showed an MAR index greater than 0.2. Two VRSA isolates (40%) were positive for the vanA gene. The higher prevalence of MRSA and significant rate of VRSA in this study recommend routine surveillance for the MRSA and VRSA in hospital settings before empirical therapy.

High Prevalence of Methicillin-Resistant Staphylococcus aureus among Healthcare Facilities and Its Related Factors in Myanmar (2018-2019)

BACKGROUND

Antimicrobial resistance (AMR) is a growing global health problem. Staphylococcus aureus (SA) is a common bacterium associated with a variety of community and hospital infections. Methicillin-resistant Staphylococcus aureus (MRSA) accounts for most SA related morbidity and mortality. In this study, we determined the prevalence and factors associated with SA and MRSA in Myanmar.

METHODS

We collected the data retrospectively by reviewing an electronic register containing the results of bacterial culture and antibiotic susceptibility testing of biological specimens received from healthcare facilities during 2018-2019.

RESULTS

Of the 37,798 biological specimens with bacterial culture growth, 22% (8244) were Gram-positive. Among the Gram-positive bacteria, 42% (2801) were SA, of which 48% (1331) were judged as MRSA by phenotypic methods. The prevalence of MRSA was higher in the older age groups, in female patients, in urine specimens and specimens received from the intensive care unit and dermatology departments. One site (Site F) had the highest MRSA prevalence of the seven AMR sentinel sites. Most SA isolates were sensitive to vancomycin (90%) by phenotypic methods.

CONCLUSIONS

The high prevalence of MRSA indicates a major public health threat. There is an urgent need to strengthen the AMR surveillance and hospital infection control program in Myanmar.