Crohn's disease complicated by intestinal infection with methicillin-resistant Staphylococcus aureus

We report on a 24-year-old male patient with history of bloody diarrhea, abdominal pain and vomiting. Endoscopy revealed massive ulcerative discontinuous proctosigmoiditis with deep, sharply demarcated epithelial denudations and enterotoxigenic methicillin-resistant Staphylococcus aureus (MRSA) was detected in mucosal biopsies. After treatment with linezolide and steroids, a significant amelioration of colitis was detected and testing for MRSA became negative. In face of the case presented here, we suggest that in patients with refractory inflammatory bowel disease (IBD), microbiological assessment should be performed to detect a possible Staphylococcus aureus infection in order to initiate an antimicrobial treatment in addition to IBDspecific treatment.

Methicillin-resistant Staphylococcus aureus pneumonia in diabetics: a single-center, retrospective analysis

Background: Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia is an important issue with significant morbidity and mortality in clinical practice, especially in diabetes mellitus (DM). Studies focusing on S. aureus pneumonia in DM is limited, we sought to make a relatively comprehensive exploration of clinical characteristics, antimicrobial resistance, and risk factors for mortality of S. aureus pneumonia in DM and non-diabetics mellitus (non-DM). Methods: A retrospective study was conducted in Ruijin Hospital from 2014 to 2017. The characteristics of DM and non-DM patients were assessed, including demographics, comorbidities, using of invasive mechanical ventilation, Hemoglobin A1c (HbA1C), confusion, urea, respiratory rate, blood pressure, age ≥65 years (CURB-65) score, length of hospital stay, clinical outcomes, antimicrobial susceptibility. Independent risk factors for mortality were identified by univariate and multivariate logistic regression analysis. Results: A total of 365 patients with S. aureus pneumonia were included in our study, including 144 with DM and 221 non-DM. DM patients were more susceptible to MRSA infection (65.3% vs. 56.1%, P > 0.05), suffered from much severer pneumonia with a higher CURB-65 score, invasive mechanical ventilation rate (46.5% vs. 28.1%, P < 0.01) and mortality rates (30.6% vs. 23.1%, P > 0.05);almost all DM patients had higher antimicrobial resistance than non-DM patients, the DM group had a higher coinfection rate (47.2% vs. 45.7%, P > 0.05), and Acinetobacter baumannii was the most common bacterium in DM, while Klebsiella pneumoniae ranked first in patients with non-DM. Independent risk factors for pneumonia-related mortality were MRSA and CURB-65. Higher HbA1c levels were linked to a higher MRSA infection and co-infection rate and more severe pneumonia, leading to an increase in mortality. Conclusions: DM patients with poor glucose control are more susceptible to MRSA infection. They suffer from higher antimicrobial resistance, a higher co-infection rate, and much severer pneumonia than non-DM. MRSA itself is an independent risk factor for mortality in all patients.

Phage therapy: An alternative to antibiotics in the age of multi-drug resistance

The practice of phage therapy, which uses bacterial viruses(phages) to treat bacterial infections, has been around for almost a century. The universal decline in the effectiveness of antibiotics has generated renewed interest in revisiting this practice. Conventionally, phage therapy relies on the use of naturally-occurring phages to infect and lyse bacteria at the site of infection. Biotechnological advances have further expanded the repertoire of potential phage therapeutics to include novel strategies using bioengineered phages and purified phage lytic proteins. Current research on the use of phages and their lytic proteins against multidrug-resistant bacterial infections, suggests phage therapy has the potential to be used as either an alternative or a supplement to antibiotic treatments. Antibacterial therapies, whether phage-or antibiotic-based, each have relative advantages and disadvantages; accordingly, many considerations must be taken into account when designing novel therapeutic approaches for preventing and treating bacterial infection. Although much about phages and human health is still being discovered, the time to take phage therapy serious again seems to be rapidly approaching.

Antibiotic Metabolites from the Coral-Associated Actinomycete Streptomyces sp. OUCMDZ-1703

From the oligotrophic culture of a soft coral-associated actinomycetes strain, Streptomyces sp. OUCMDZ-1703, we isolated and identified two new chlorinated polyketides that we named strepchloritides A and B （1 and 2）, three thiazole derivatives known as watasemycin A （3）, pulicatin G （4） and aerugine （5）, along with pyrrole- 2-carboxamide, furan-2-carboxamide and 1-（3,5-dihydroxyphenyl）ethanone. The new structures of 1 and 2 were determined by spectroscopic studies such as 1D- and 2D-NMR and MS analyses, while the known compounds were identified by comparison of the NMR data with those in literatures. The results showed that actinomycete strain OUCMDZ-1703 could use the relative high ratio of chlorine in the oligotrophic medium to synthesize chlorinated natural products. New compounds 1 and 2 displayed cytotoxicity against the MCF-7 ceils with ICs0 values of 9.9 and 20.2 ~tmoloL-1, respectively. Thiazole derivatives 3 and 5 were first found to be active against three clinical strains of methicillin-resistant Staphylococcus aureus （MRSA082, MRSA111 and MRSA234） with the same MIC/MBC values of 7.81/7.81 μg·mL-1.