Enteral vancomycin and probiotic use for methicillin-resistant Staphylococcus aureus antibiotic-associated diarrhoea

Probiotics and Their Bioproducts: A Promising Approach for Targeting Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus

Antibiotic resistance is a serious global health problem that poses a threat to the successful treatment of various bacterial infections, especially those caused by methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). Conventional treatment of MRSA and VRE infections is challenging and often requires alternative or combination therapies that may have limited efficacy, higher costs, and/or more adverse effects. Therefore, there is an urgent need to find new strategies to combat antibiotic-resistant bacteria. Probiotics and antimicrobial peptides (AMPs) are two promising approaches that have shown potential benefits in various diseases. Probiotics are live microorganisms that confer health benefits to the host when administered in adequate amounts. AMPs, usually produced with probiotic bacteria, are short amino acid sequences that have broad-spectrum activity against bacteria, fungi, viruses, and parasites. Both probiotics and AMPs can modulate the host immune system, inhibit the growth and adhesion of pathogens, disrupt biofilms, and enhance intestinal barrier function. In this paper, we review the current knowledge on the role of probiotics and AMPs in targeting multi-drug-resistant bacteria, with a focus on MRSA and VRE. In addition, we discuss future directions for the clinical use of probiotics.

Methicillin-Resistant Staphylococcus aureus-Associated Diarrhea in a Critically Ill Burn Patient

Described in surgical patients after antibiotic use in the 1950s and 1960s, Staphylococcus aureus (S. aureus) enterocolitis is a rare form of nosocomial diarrhea. However, S. aureus is not routinely tested like Clostridium difficile (C. difficile). We report a case of methicillin-resistant S. aureus (MRSA) enterocolitis found on stool culture in a 22-week pregnant female with a previously negative nasal MRSA culture, and a total burn surface area greater than 60%. She also developed necrotizing MRSA pneumonia and bacteremia. After starting broad-spectrum antibiotic for the necrotizing pneumonia with subsequent acute respiratory distress syndrome, the patient exhibited large voluminous diarrhea that tested positive for MRSA and negative for C. difficile in the stool culture. Similar to other reports of high-volume diarrhea, the diarrhea resolved quickly with enteral vancomycin. S. aureus should be considered along with C. difficile during the workup of nosocomial diarrhea, especially with exposure to broad-spectrum antibiotics in the critically ill patient.

A Case of Postoperative Methicillin-Resistant Staphylococcus aureus Enterocolitis in an 81-Year-Old Man and Review of the Literature

Patient: Male, 81-year-old

Final Diagnosis: Methicillin-resistant Staphylococcus aureus bacteremia • Methicillin-resistant Staphylococcus aureus enterocolitis

Symptoms: Diarrhea • sepsis

Medication: —

Clinical Procedure: Computed tomography • echocardiography • polymerase chain reaction • whipple procedure

Specialty: Gastroenterology and Hepatology • Infectious Diseases • Surgery

Use of a water-based probiotic to treat common gut pathogens

This work reports the anti-pathogenic effect of a commercially available water-based probiotic suspension, Symprove™, against three commonly encountered infectious organisms; Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA) and Shigella sonnei. An isothermal calorimetric assay was used to the monitor growth of the species individually and in binary combinations, while colony plate counting was used to enumerate viable cell numbers. It was observed that all pathogenic species were faster growing than the probiotic bacteria in Symprove™ after inoculation into growth medium yet in all instances bacterial enumeration at the end of the experiments revealed a significant reduction in the pathogen population compared with the controls. A control population between 10⁸ and 10⁹ CFU/ml was obtained for E. coli and S. sonnei whilst approximately 10⁶ CFU/ml was obtained for MRSA. Upon co-incubation for 48 h, no viable counts were obtained for E. coli; a 4-log reduction was obtained for S. sonnei whilst MRSA numbers were down to less than 10 cells/ml. The results show that Symprove™ has antipathogenic activity against E. coli, S. sonnei and MRSA.

The Use of Microbiome Restoration Therapeutics to Eliminate Intestinal Colonization With Multidrug-Resistant Organisms

Antibiotic resistance (AR) has been described by the World Health Organization as an increasingly serious threat to global public health. Many mechanisms of AR have become widespread due to global selective pressures such as widespread antibiotic use. The intestinal tract is an important reservoir for many multidrug-resistant organisms (MDROs), and next-generation sequencing has expanded understanding of the resistome, defined as the comprehensive sum of genetic determinants of AR. Intestinal decolonization has been explored as a strategy to eradicate MDROs with selective digestive tract decontamination and probiotics being notable examples with mixed results. This review focuses on fecal microbiota transplantation and the early evidence supporting its efficacy in decolonizing MDROs and potential mechanisms of action to reduce AR genes. Current evidence suggests that fecal microbiota transplantation may have promise in restoring healthy microbial diversity and reducing AR, and clinical trials are underway to better characterize its safety and efficacy.

Methicillin-Resistant Staphylococcus aureus as a Probable Cause of Antibiotic-Associated Enterocolitis

Antibiotic-associated diarrhea is typically associated with Clostridium difficile. However, Staphylococcus aureus has also been described as a cause of antibiotic-associated enterocolitis and diarrhea and is likely an underrecognized etiology. We present a case of enterocolitis and urinary tract infection caused by methicillin-resistant S. aureus following antibiotic treatment.

Fecal Carriage of Staphylococcus aureus in the Hospital and Community Setting: A Systematic Review

BACKGROUND AND RATIONALE

Staphylococcus aureus fecal carriage has been identified as a potential source for nosocomial transmission and a risk factor for disease development. This systematic review determined the overall S. aureus [including methicillin susceptible and resistant S. aureus (MSSA and MRSA)] fecal carriage rates within the community and healthcare settings.

METHODOLOGY

Peer-reviewed articles indexed in Medline, Scopus, Academic Search Premier, Africa-Wide Information, CINAHL, and Web of Science were identified using applicable and controlled vocabulary through to 11 November 2015. Eligible studies were ascertained by three independent reviewers. Random-effects meta-analyses of proportions were performed to determine S. aureus, MSSA and MRSA fecal carriage rates reported by eligible studies.

RESULTS

Twenty six studies were included in this review. The pooled estimates for S. aureus, MSSA and MRSA fecal carriage were 26% (95% confidence interval (CI): 16.8-36.3%), 86% (95% confidence interval (CI): 65.9-97.9%) and 10% (95% CI: 0.7-27.0%), respectively. Fecal S. aureus carriage rates increased on average from 10 to 65% during the first 8 weeks of life, followed by an average carriage rate of 64% at 6 months and 46% at 1 year of life. Genotyping techniques were employed mainly in studies conducted in developed countries and comprised largely of gel-based techniques. Six studies reported on the role of S. aureus fecal strains in diarrhea (n = 2) and the risk for acquiring infections (n = 4). Eight of the 26 studies included in this review performed antibiotic susceptibility testing of S. aureus fecal isolates.

CONCLUSION

This study provides evidence that screening for S. aureus fecal carriage, at least in populations at high risk, could be an effective measure for the prevention of S. aureus transmission and infection in the healthcare and community setting. More well-structured studies need to be conducted and sequence-based genotyping techniques should be employed for the comparison of isolates on a global scale in both developing and developed countries.

Case of antibiotic-associated diarrhea caused by Staphylococcus aureus enterocolitis

PURPOSE

A case of Staphylococcus aureus enterocolitis (SEC) misdiagnosed as toxin-negative Clostridium difficile is reported.

SUMMARY

An 82-year-old white man weighing 50 kg (body mass index, 16.8 kg/m(2)) was transported from an assisted living facility to the emergency department with the chief complaints of weakness, nausea, and diarrhea for one week and one bright-red stool on the morning of admission. Before hospital admission, he was treated for a urinary tract infection with ciprofloxacin 500 mg twice daily for 10 days. Stool cultures were negative for C. difficile but positive for S. aureus. The antimicrobial stewardship pharmacist recommended treatment with vancomycin 125 mg orally every 6 hours for staphylococcal colitis. Oral vancomycin was discontinued after three doses on the morning of hospital day 8 after a gastroenterology consultation. Within 48 hours of the discontinuation of oral vancomycin, the patient had eight stools per day. Vancomycin was reinitiated and the patient's symptoms began to again improve. On hospital day 19, the patient was discharged with a prescription for 7 more days of therapy with vancomycin (to complete a 15-day course) and a diagnosis of toxin-negative C. difficile, despite having symptoms consistent with SEC and an enteric culture positive for S. aureus.

CONCLUSION

An 82-year-old man was transferred from an assisted living facility to the hospital with profuse diarrhea and dehydration. Enteric cultures were positive for methicillin-resistant S. aureus with multiple negative C. difficile toxin B assays. Appropriate therapy was delayed and the patient potentially misdiagnosed with toxin-negative C. difficile when the clinical symptoms and diagnostic testing were consistent with SEC.