Characterization of nalidixic acid-resistant and fluoroquinolone-reduced susceptible Salmonella Typhimurium in swine

From 2001 to 2008, a total of 27 isolates of Salmonella enterica serovar Typhimurium were obtained from 930 swine. All 27 isolates were resistant to streptomycin and tetracycline. Seventeen isolates were multidrug resistant to more than three antimicrobial agents. Seven of these multidrug-resistant isolates were pentaresistant to ampicillin, chloramphenicol, streptomycin, tetracycline, and nalidixic acid. Among 27 isolates, 14 isolates (51.8 %) were nalidixic acid resistant (MIC, ≥128 μg/ml) and had reduced susceptibility to various quinolones (MIC, 0.125 to 2 μg/ml). When quinolone resistance-determining regions in the gyrA and gyrB genes of these isolates were sequenced, 13 isolates had Asp87→Tyr mutations and 1 isolate had Asp87→Gly mutation in the quinolone resistance-determining region of gyrA, whereas no mutation was found in gyrB. Genes for qnrA, qnrB, and qnrS were not detected by PCR with specific primers. Pulsed-field gel electrophoresis of genomic DNA digested with Xba I showed two patterns suggesting a clonal spread of Salmonella Typhimurium in swine in Korea.

Serous Retinal Detachment in a Patient with Rhino-Orbital Mucormycosis

BACKGROUND

Rhino-orbital mucormycosis is a difficult disease to treat. We report one case of rhino-orbital mucormycosis, complicated by serous retinal detachment, that responded to aggressive treatment.

CASE

A 38-year-old man with diabetic ketoacidosis was referred to the emergency department of our hospital with fever, proptotic right eye, and complaint of lethargy.

OBSERVATIONS

Fundus examination showed serous retinal detachment and focal lesions of retinitis with exudate at the inferior portion coincident with the position of opacification in the orbit on MRI. Fluorescein angiography showed pooling of dye in the detached retina and leakage from focal lesions of retinitis. We thoroughly removed the large necrotic materials in the orbit and sinus through the lower conjunctiva without enucleation or exenteration. Microscopic examination and culture of the necrotic materials that were removed from the orbit proved that the patient had mucormycosis. The serous retinal detachment improved 10 days after orbital debridement combined with intravenous and local (intraorbital) amphotericin B treatment. Visual acuity recovered to 20/50.

CONCLUSION

We propose that inflammation of the sclera in close contact with necrotic fungi materials may cause serous retinal detachment.

Hepatocellular carcinoma metastatic to the orbit

Orbital metastases of hepatocellular carcinoma are rare. The authors report a case of hepatocellular carcinoma metastatic to the orbit. A 56-year-old woman with hepatitis B infection as confirmed serologic test for hepatitis B surface antigen (HBsAg) demonstrated superior displacement of the left eyeball. The clinical appearance of the patient demonstrated an inferior displacement of the right eye. MRI disclosed an orbital mass that extended toward the lower eyelid and into the temporal fossa with destruction of the lateral orbital wall. Upon subsequent abdominal computed tomographic scans, the primary tumor was found in the liver. A biopsy specimen of the orbit showed trabecular structures with eosinophilic cytoplasm. Bile canaliculi and sinusoids were also seen. The tumor cells showed vesicular nuclei with mitoses. Immunohistochemical markers such as high-molecular-weight keratin and alpha-fetoprotein showed a positive response. However, immunohistochemical markers such as low-molecular-weight keratin and polyclonal carcinoembryonic antigen showed as negative. We diagnosed the tumor as a hepatocellular carcinoma metastatic to the orbit. A review of the pertinent literature disclosed relatively few occurrences of hepatocellular carcinoma metastasizing to the orbit.