Whole-Genome Analysis of bla(CTX-M-55)-Carrying Escherichia coli Among Pigs, Farm Environment, and Farm Workers

No abstract available.

Differences in Colistin-resistant Acinetobacter baumannii Clinical Isolates Between Patients With and Without Prior Colistin Treatment

BACKGROUND: The increasing morbidity and mortality rates associated with Acinetobacter baumannii are due to the emergence of drug resistance and the limited treatment options. We compared characteristics of colistin-resistant Acinetobacter baumannii (CR-AB) clinical isolates recovered from patients with and without prior colistin treatment. We assessed whether prior colistin treatment affects the resistance mechanism of CR-AB isolates, mortality rates, and clinical characteristics. Additionally, a proper method for identifying CR-AB was determined. METHODS: We collected 36 non-duplicate CR-AB clinical isolates resistant to colistin. Antimicrobial susceptibility testing, Sanger sequencing analysis, molecular typing, lipid A structure analysis, and in vitro synergy testing were performed. Eleven colistin-susceptible AB isolates were used as controls. RESULTS: Despite no differences in clinical characteristics between patients with and without prior colistin treatment, resistance-causing genetic mutations were more frequent in isolates from colistin-treated patients. Distinct mutations were overlooked via the Sanger sequencing method, perhaps because of a masking effect by the colistin-susceptible AB subpopulation of CR-AB isolates lacking genetic mutations. However, modified lipid A analysis revealed colistin resistance peaks, despite the population heterogeneity, and peak levels were significantly different between the groups. CONCLUSIONS: Although prior colistin use did not induce clinical or susceptibility differences, we demonstrated that identification of CR-AB by sequencing is insufficient. We propose that population heterogeneity has a masking effect, especially in colistin non-treated patients; therefore, accurate testing methods reflecting physiological alterations of the bacteria, such as phosphoethanolamine-modified lipid A identification by matrix-assisted laser desorption ionization-time of flight, should be employed.

Increasing Incidence of Listeriosis and Infection-associated Clinical Outcomes

BACKGROUND: Listeriosis caused by Listeria monocytogenes has a high case-fatality rate (CFR) of approximately 20% to 30%. An increasing incidence of listeriosis has been reported in many countries recently. We investigated the annual incidence, clinical characteristics, and outcomes of listeriosis at three different hospitals in Korea and evaluated the effects of appropriate empiric antimicrobial treatments on patient outcomes. METHODS: We retrospectively collected the data of all culture-positive cases of human listeriosis from three hospitals of different sizes in Korea during 2006–2016 and calculated the annual number of cases and incidence per 100,000 admissions. RESULTS: A total of 58 patients with L. monocytogenes were included in this study. The incidence of listeriosis was significantly higher in 2013–2016 than in 2006–2012 (RR 3.1; 95% CI 1.79–5.36; P < 0.001), mainly because of an increase in patients over 60 years of age (RR 3.69; 95% CI 1.70–8.02; P < 0.001). Multivariate analysis showed that healthcare-associated infection (adjusted OR, 12.15; 95% CI, 2.56–86.01; P=0.004) and empirical treatment with first-line antimicrobial agents (adjusted OR, 0.08; 95% CI, 0.00–0.63; P=0.044) were associated with CFR. CONCLUSIONS: Healthcare-associated infections caused by L. monocytogenes are associated with high CFR. Adequate initial empirical treatments could reduce CFR, suggesting that careful consideration of an empirical antimicrobial regimen is warranted for elderly or immunocompromised patients admitted to the hospital.

Increase of Clostridium difficile in Community; Another Worrisome Burden for Public Health / 대한임상미생물학회지

BACKGROUND: Increasing rates of Clostridium difficile infection (CDI) have been reported mainly in Europe and North America; however, only limited reports have originated in Korea. The current epidemiology of CDI in the community could help to understand the outpatient healthcare environment and to extend infection control measures to outpatient settings. METHODS: C. difficile isolates in NHIS Ilsan Hospital from 2012 to 2014 were included in this study. Clinical characteristics, acquisition types, and previous antimicrobial therapy were obtained via Electronic Medical Records. C. difficile culture was performed only in unformed stool. Toxin was positive by enzyme-linked fluorescent immunoassay (ELFA) in 247 specimens. In addition, toxin B and binary toxin gene were detected by PCR in 57 specimens. CDI was defined by toxigenic C. difficile isolation in unformed stool. RESULTS: In the previous 3 years, 251 unduplicated C. difficile cases have been detected; 168 healthcare facility- associated hospital onset (HCFA-HO), 45 healthcare facility-associated community onset (HCFA-CO), and 38 community-associated (CA). Toxin positive rates by ELFA for toxin A&B were HCFA-HO 50.6% (84/166), HCFA-CO 41.9% (18/43), and CA 42.1% (16/38). Toxin positive rate by PCR for tcdB were HCFA-HO 62.9% (22/35), HCFA-CO 69.2% (9/13), and CA 100% (9/9). No binary toxin (cdtA/cdtB) was detected in 57 cases. CONCLUSION: Community-associated CDI may be underestimated in Goyang province, Korea, especially by commonly used ELFA toxin assay. The spread of community-associated CDI should be recognized as an increasing burden of public health.

Clinical Experience of Power- Assisted Lipoplasty(PAL)

Many people desire body contouring. Liposuction is a powerful tool for plastic surgeons in body contouring and widely used in many countries. The ideal liposuction technique allows greater volumes to be aspirated while minimizing blood loss, operative time, and complication. The mechanism of liposuction involves mechanical suctioning, followed by destruction of fat tissue by cannula movement. In PAL, a cannula powered by compressed nitrogen gas or an electric power source reciprocates between 2000 and 4000 cpm with a 2-3mm amplitude. We have treated 12 patients by PAL during 2001 January-September with excellent results. PAL made surgeons less fatique and discomfort, and resulted in shorter operation times, and decreased seroma formation and less scars at the incision site. PAL is also effective in fibrous fat aspiration in case of gynecomastia, superficial suction, large volume removal, and secondary liposuction. Conclusively the technique is safe, fast and capable of producing results comparable to those achieved with traditional or ultrasonic-assisted lipoplasty.

Tissue Engineered Neocartilage using Polyglycolic Acid(PGA) and Chondrocyte

Neomorphogenesis using tissue engineering technique by cell transplantation with biodegradable polymer has been introduced as a new method to achieve organ replacement or to create new tissues. Using this tissue engineering technique, neocartilage formation can be possible when isolated chondrocyte is combined with biocompatible and biodegradable polymer scaffolds. The purposes of this study are to investigate whether chondrocyte-polyglycolic acid(PGA) polymer can be designed to induce cartilage formation in a predetermined shape, to analyze the properties of neocartilage by histologic and immunohistochemical study. Chondrocytes were isolated from the articular cartilage of swine shoulder joint and seeded onto four PGA polymers(disc shape, diameter;1cm, thickness; 0.3 cm) at a concentration of 5 x 107 chondrocytes per cm3. Chondrocyte-PGA polymers were implanted into left side of subcutaneous pockets on the dorsa of 4 athymic mice. PGA polymers without chondrocyte were implanted into the right side of subcutaneous pockets of the same animals as a control study. The chondrocyte-PGA polymers were harvested 2, 4, 6 and 8 weeks after implantation and investigated grossly, histologically and immunohistochemically. Chondrocytes were also cultured in Ham's F-12 medium under 5% CO2 incubator at 37degrees C and analyzed by histologic and immunohistologic study. The analysis confirmed the following results: 1. In vitro study, it was confirmed by Hematoxylin-Eosin (H-E) stain and toluidine blue stain that histologic findings of cultured chondrocyte corresponded to normal chondrocyte. 2. After 4 weeks of implantation of chondrocyte-PGA polymer, specimens changed in gross finding to pearly white opalescence and firm on palpation and this findings were accentuated progressively. But PGA polymers without chondrocyte could not maintain its shape and were resolved gradually. 3. The appearance of normal immature cartilage was detected at 2 weeks of implantation of chondrocyte-PGA polymer in H-E stain and toluidine blue stain. Maturation process of cultured chondrocyte was observed by steps in the 4th, 6th and 8th week. 4. Using the immunohistochemistric study, the presences of Type II collagen and CD44 were confirmed in cultured chondrocytes. This finding meant that neocartilage could inherit the original properties of chondrocyte. 5. Nipple-shaped cartilage discs which could assure the mechanical and histologic properties of normal cartilage were successfully created. It seems to be possible to apply this method to other kinds of manufacture with various shaped-PGA polymer. This study showed not only new cartilage formation could be possible using chondrocyte and PGA polymer but also engineered tissue could be one of the modalities to treat the patients suffering from the shortage of tissue in the future. With further prudent researches, tissue engineering technique can be a distinguished armament in reconstruction of human body including cartilage.

Resurfacing in Penile Paraffinoma by Groin Flap

Paraffinoma induces many unexpected complications such as tissue necrosis, granuloma formation, hypersensitivity, embolism and even carcinoma. The treatment modality is known to be primary repair, flap surgery, skin graft, radiotherapy and high frequency current treatment after the excision of the lesion. Although these methods can remove the paraffinoma and resurface penile shaft, various complications such as skin tension after surgery, hypertrophic scars, difficulty of erection, and deficiency of bulkiness are frequently occurred. Groin flap is the proper method for the patients who want simultaneously soft tissue reconstruction and augmentation of penis. A 32 year-old male patient who visited our clinic had firm mass, abscess, skin necrosis, and dyspareunia after the injection of paraffin into penis 3 months ago. Reconstruction was executed using right side of the groin flap after the radical resection of the whole tissues ruined by infections and infiltration of paraffin. The penile bulkiness, erectile function and duration of erection was all satisfactory. The follow-up period was 7 months after the surgery and no specific complication was developed. Groin flap is the satisfactory method to enhance penile bulkiness as well as resurface the lesion.