Life-threatening MRSA sepsis with bilateral pneumonia, osteomyelitis, and septic arthritis of the knee in a previously healthy 13-year-old boy: a case report

Invasive Community-Acquired Methicillin-Resistant Staphylococcus aureus With Aortic Aneurysm in a 10-Year-Old Patient: A Case Report

The clinical presentation of disseminated community-acquired Methicillin-resistant Staphylococcus aureus (MRSA) in young pediatric patients without a known predisposing risk factor poses a diagnostic dilemma due to its non-specific clinical symptoms. This can lead to delayed initiation of appropriate antibiotics and surgical interventions to achieve a favorable outcome and prevent mortality. Appropriate imaging with good clinical judgment is required in the management of this infection. Outpatient surveillance for subacute and chronic complications is required for a good long-term prognosis. Few reported cases of disseminated infections with aortic aneurysm exist in the literature. We report a case of a child without predisposing risk factors managed for community-acquired MRSA sepsis, acute respiratory distress syndrome (ARDS), multiple abscesses, osteomyelitis, and necrotizing pneumonia with a post-discharge unruptured aortic aneurysm. This case emphasizes the importance of post-discharge monitoring even in patients with favorable outcomes.

Novel fluorobenzothiazole as a dual inhibitor of gyrase B and topoisomerase IV against Gram-positive pathogens

Aim: The development of a novel inhibitor targeting gyrase B and topoisomerase IV offers an opportunity to combat multidrug resistance. Methods: We investigated the activity of RBx 10080758 against Gram-positive bacteria in vitro and in vivo. Results: RBx 10080758 showed a potent 50% inhibitory concentration of 0.13 μM and 0.25 μM against gyrase B and topoisomerase IV, respectively, and exhibited strong whole-cell in vitro activity with MIC ranges of 0.015-0.06 and 0.015-0.03 μg/ml against Staphylococcus aureus and Streptococcus pneumoniae, respectively. In a rat thigh infection model with methicillin-resistant S. aureus, RBx 10080758 at 45 mg/kg exhibited a >3 log10 CFU reduction in thigh muscles. Conclusion: RBx 10080758 displayed potent activity against multiple multidrug-resistant Gram-positive bacteria with a dual-targeting mechanism of action.

Paediatric and adult patients from New Caledonia Island admitted to the ICU for community-acquired Panton-Valentine leucocidin-producing Staphylococcus aureus infections

Severe infections involving Panton-Valentine leukocidin-producing Staphylococcus aureus (PVL + Sa) are increasing. This monocentre, retrospective descriptive cohort assessed clinical characteristics and outcome of paediatric and adult patients admitted for community-acquired PVL + Sa infections to the unique intensive care unit (ICU) on New Caledonia Island. Overall, 72 patients (including 23 children) admitted for acute respiratory failure (42%), sepsis/septic shock (21%), and/or postoperative care (32%) were analysed. Most patients had pulmonary (64%), skin/soft tissue (SSTI) (54%) and/or osteoarticular (38%) infections. Multifocal infections (≥ 2 sites) and bacteraemia were reported in 65% and 76% of the patients, respectively. Methicillin-resistant S. aureus isolates were reported in 61% of adult cases versus 30% in children (p < 0.05). Mechanical ventilation, vasoactive support and source control were administered in 53%, 43% and 58% of the patients, respectively. All paediatric patients received adequate empirical antibiotic therapy versus 30/49 adults (p < 0.001). Adequate documented therapy was obtained ≤ 72 h in 70/72 (97%) patients. Death was only reported in adults (n = 10 (14%)), mainly during pulmonary infection (22%), SSTIs (21%) and bacteraemia (24%)). In summary, in ICU patients from New Caledonia Island the clinical presentation of severe community-acquired PVL + Sa infections seems different from Western European observations with high rates of multifocal infections and methicillin-resistant strains.

Necrotizing pneumonia and purulent meningitis caused by bloodstream infection of CA-MRSA in a child: A rare case report

CASE PRESENTATION

We report the case of a girl aged 2 years and 10 months who had fever for 2 days, vomiting, poor mental status for 1 day, and one episode of convulsions.

SYMPTOMS AND SIGNS

The patient experienced a rapid onset of symptoms with fever, vomiting, and convulsions. Upon physical examination on admission, she presented with the following: temperature 38.6°C; pulse 185 beats/min; respiration 49 beats/min; blood pressure 89/51 mmHg; drowsiness; piebald skin all over her body; rice-grain-sized pustular rashes scattered on the front chest and both lower limbs, protruding from the surface of the skin; bilateral pupils that were equal in size and a circle with a diameter of about 3.0 mm, and slow light reflex; cyanotic lips; shortness of breath; positive for the three-concave sign; a small amount of phlegm that could be heard in both lungs; capillary refill time of 5 s; cold extremities; and a positive Babinski sign.

DIAGNOSTIC METHOD

A chest computed tomography scan showed multiple nodular and flake-like high-density shadows of varying sizes in each lobe in bilateral lungs, and a cavity with blurred edges could be seen in some nodules. A cranial magnetic resonance imaging examination demonstrated that the hyperintensity of diffusion-weighted imaging could be observed on the left cerebellar hemisphere and left parietal blade. Blood cultures, sputum, cerebrospinal fluid, and bronchoalveolar lavage fluid (BALF) by fiberoptic bronchoscopy all indicated the growth of methicillin-resistant Staphylococcus aureus (MRSA).

TREATMENT METHODS

After admission, the child was given meropenem combined with vancomycin, cefoperazone sulbactam combined with rifamycin, linezolid (oral) for anti-infection successively, and other adjuvant therapies.

CLINICAL OUTCOMES

The patient recovered clinically and was discharged from our hospital.

RECOMMENDED READERS

Neurology; Respiratory Medicine; Infectious Diseases Department.

Panton-valentine leukocidin Staphylococcus aureus severe infection in an infant: a case report and a review of the literature

Background

Panton-Valentine leukocidin (PVL) is one of the major virulence factor of Staphylococcus aureus (SA) that might be associated with invasive life-threating infections. A prompt diagnosis and adequate treatment are essential in achieving the best outcome and avoiding serious sequelae. We describe a case of severe invasive PVL-SA infection in an infant. A literature review starting from 2010 was also performed in order to discuss clinical presentations, radiological findings, treatment and outcome.

Case presentation

This is a case of a 6-month-old boy who rapidly developed high fever and poor general condition. He was diagnosed as having multiple muscular abscesses, multiple foci of osteomyelitis and bloodstream infections caused by Panton-Valentine leukocidin Methicillin-resistant Staphylococcus aureus. He received intravenous antibiotics and surgical drainage of the abscess with progressive recovery.

Conclusion

Our report highlights the importance of improving awareness of this severe infection, as a prompt diagnosis and adequate manage is essential in order to save life and to prevent serious complications.

Potentiated antimicrobial blue light killing of methicillin resistant Staphylococcus aureus by pyocyanin

As antimicrobial resistance continues to threaten the efficacy of conventional antibiotic therapy, it is paramount that we investigate innovative approaches to treat infectious diseases. In this study, we investigated the antimicrobial capabilities of the innovative combination of antimicrobial blue light (aBL; 405 nm wavelength) with the Pseudomonas aeruginosa pigment pyocyanin against methicillin resistant Staphylococcus aureus (MSRA. We explored the effects of different radiant exposures of aBL and increasing concentrations of pyocyanin against planktonic cells and those within biofilms. In addition, we investigated the effect of the aBL/pyocyanin on the endogenous staphyloxanthin pigment, as well as the role of hydrogen peroxide and singlet oxygen scavenging in the efficacy of this combination. Lastly, we investigated the potential for the aBL/pyocyanin to reduce the MRSA burden within a proof-of-principle mouse abrasion infection model. We found pyocyanin to be a powerful potentiator of aBL activity under all in vitro conditions tested. In addition, we serendipitously discovered the capability of the aBL/pyocyanin combination to bleach staphyloxanthin within colonies of MRSA. Furthermore, we established that singlet oxygen is an important mediator during combined aBL/pyocyanin exposure. Moreover, we found that the combination of aBL and pyocyanin could significantly reduce the viability of MRSA within a proof-of-principle early onset MRSA skin abrasion infection. Exposure to the treatment did not have deleterious effects on skin tissue. In conclusion, the combination of aBL and pyocyanin represents a potentially powerful therapeutic modality for the treatment of infections caused by MRSA.

Dual-wavelength photo-killing of methicillin-resistant Staphylococcus aureus

With the effectiveness of antimicrobials declining as antimicrobial resistance continues to threaten public health, we must look to alternative strategies for the treatment of infections. In this study, we investigated an innovative, drug-free, dual-wavelength irradiation approach that combines 2 wavelengths of light, 460 nm and 405 nm, against methicillin-resistant Staphylococcus aureus (MRSA). MRSA was initially irradiated with 460-nm light (90-360 J/cm2) and subsequently irradiated with aliquots of 405-nm light (54-324 J/cm2). For in vivo studies, mouse skin was abraded and infected with approximately 107 CFUs of MRSA and incubated for 3 hours before irradiating with 460 nm (360 J/cm2) and 405 nm (342 J/cm2). Naive mouse skin was also irradiated to investigate apoptosis. We found that staphyloxanthin, the carotenoid pigment in MRSA cells, promoted resistance to the antimicrobial effects of 405-nm light. In addition, we found that the photolytic effect of 460-nm light on staphyloxanthin attenuated resistance of MRSA to 405-nm light killing. Irradiation of 460 nm alone did not elicit any antimicrobial effect on MRSA. In a proof-of-principle mouse skin abrasion infection model, we observed significant killing of MRSA using the dual-wavelength irradiation approach. However, when either wavelength of light was administered alone, no significant decrease in bacterial viability was observed. Moreover, exposure of the dual-wavelength irradiation to naive mouse skin did not result in any visible apoptosis. In conclusion, a dual-wavelength irradiation strategy may offer an innovative, effective, and safe approach for the treatment of skin infections caused by MRSA.