Cystic and solitary nodular pulmonary metastases in a patient with low-grade endometrial stromal sarcoma: A case report and literature review.

Pulmonary metastases of endometrial stromal sarcoma (ESS) are uncommon and can be difficult to diagnose. The aims of the present study were to investigate the clinical and pathological features, and enhance the awareness of pulmonary metastases in patients with low-grade ESS. The study reports a case of low-grade ESS that resulted in cystic and nodular pulmonary metastases. Furthermore, the PubMed database was searched using 'pulmonary metastases of low-grade endometrial stromal sarcoma' as the key phrase. The literature on pulmonary metastases of low-grade ESS was reviewed and 35 cases were included in the present study. The clinical manifestations, imaging data, pathological features, treatment and prognosis of the 35 previously reported cases and the current case were retrospectively analyzed. The age range of the 36 patients diagnosed with low-grade ESS was 28-65 years. The time period from confirmation of ESS to lung metastases was 1.5-27 years. In 50% of the patients, the pulmonary metastases were asymptomatic. The most common pulmonary symptom was dyspnea, followed by chest pain, pneumothorax and coughing. The most common chest imaging presentation was multiple pulmonary nodules, followed by a solitary nodule or mass. Histology was used to identify that the pulmonary metastases had the pathological features of low-grade ESS. The immunohistochemical results demonstrated strong diffuse immunoreactivity for cluster of differentiation 10, estrogen receptor and progesterone receptor in almost all the specimens. The review of the literature revealed that pulmonary metastases from low-grade ESS are rare but not negligible. Furthermore, the detailed clinical information, imaging findings and immunohistochemical detection are important for making a diagnosis.

[Antimicrobial resistance and genotyping of Acinetobacter baumannii in ICU].

OBJECTIVE: To investigate the outbreak of acinetobacter baumannii in the ICU, and to explore the antimicrobial resistance characteristics of pathogens, and therefore to determine the optimal prevention strategies. METHODS: From May to June 2007, most of the cases of infection by acinetobacter baumannii in our ICU were collected. PFGE (pulsed field gel electrophoresis) and standard disk diffusion susceptibility tests were performed on the strains isolated from the patients' body fluids including sputum, blood, urine, secretion and from the ICU environment involving the patients' bed sheet, skin surface and medical staff's hands, humidification water of ventilator tubes. RESULTS: Twelve strains were resistant to imipenem and meropenem. Colistin sulphate and tigecycline showed a high rate of antimicrobial activity against the strains, the rate of susceptibility being 100% and 91.7% respectively. These strains belonged to 3 clones (clone A, B, C) and there were 2 sub-clones (A1, A2) belonging to clone A. The sub-clone A1 was isolated from the surface of unwashed medical staff's hands and patients' body fluids. From intermediate to resistance, the antimicrobial characteristics of clone A and clone B to minocycline changed over a month, and there was one strain that was resistant to tigecycline. CONCLUSION: The outbreak of acinetobacter baumannii in the ICU was caused by carbapenem resistant acinetobacter baumannii (CRAb). The delicate changes of disk diffusion susceptibility in clones A and B occurred in one month. Unwashed hands of medical staff were probably responsible for the outbreak.

[Expression of high-level cephalosporinase due to mutation in the AmpC attenuator of a clinical Escherichia coli strain].

OBJECTIVE: To study the resistant phenotype of a clinical strain of Escherichia coli and to explore the effect of its attenuator mutation on AmpC expression. METHODS: A clinical strain of Escherichia coli 20022 (ECO20022) resistant to cefoxitin was isolated clinically. The phenotype was examined by three-dimensional methods, isoelectric focusing (IEF), and microdilution method. The regulator genes of ECO20022 were amplified and sequenced, and the difference between them was analyzed by BLAST method. Then the regulator genes were cloned into pCAT3-basic vector (a promoterless reporter gene vector). Microdilution method was used to detect the minimal inhibitory concentration (MIC) of chloramphenicol and ampicillin to this strain with E. coli ATCC25922 as quality control bacterium. ELISA was used to detect the content of chloramphenicol acetyl transferase (CAT). RESULTS: Compared to the standard E. coli K-12, there were four base substitutions, i.e., 22C-T, 26, 27TA-GT, and 32G-A in the attenuator region of ECO20022. Three-dimensional method showed that this strain was high AmpC-producing. IEF found that it produced three beta-lactamases with the values of PI of 5.4, 8.2, and 9.0 respectively. The beta-lactamase with the PI of 9.0 could be inhibited by cloxacillin but not by clavulanate. The strain was resistant to not only most of third generation cephalosporins, but also to cefepime; however it was still susceptible to carbapenem. The secondary structure of the attenuator RNA of ECO20022 was different from the traditional structure of E. coli K-12. The regulator gene was successfully cloned into pCAT3-basic vector and direct and indirect tests indicated that this regulator gene enhanced the CAT expressing level as much as 10 times that of Escherichia coli K-12. CONCLUSION: AmpC attenuator mutation leads to high AmpC expression in Escherichia coli, resulting in a significant rise of resistance level to beta-lactamase and a great menace to clinical antibiotic therapy.

[DHA-1 type cephalosporinase accompanied with SHV-12 prevailed in clinical isolates of Klebsiella pneumoniae].

OBJECTIVE: To study the prevalence, phenotype and genotype of the AmpC and ESBLs-producing clinical isolate of Klebsiella pneumoniae. METHODS: The clinical isolates of Klebsiella pneumoniae were examined by standard disk diffusion susceptibility tests, three-dimensional methods, isoelectric focusing (IEF) and microdilution methods. The conjugation experiment, multiplex PCR and DNA sequencing methods were used for further analysis. RESULTS: Four out of a total of 86 isolates tested were shown to be highly AmpC-producing by three-dimensional method. IEF showed that these strains produced a AmpC like beta-lactamase with a PI of 7.8, and DNA sequencing showed that the gene which expressed this AmpC like beta-lactamase was identical to DHA-1, a plasmid mediated cephalosporinase gene. These strains also produced an ESBL like beta-lactamase with a PI of 8.2 and the gene which expressed this beta-lactamase was identical to SHV-12. These strains were resistant not only to most of the third generation cephalosporins, but also to cefepime. However they were still susceptible to carbapenem. CONCLUSIONS: Highly AmpC-producing DHA-1 accompanied with SHV-12 in Klebsiella pneumoniae was reported here for the first time. They result in a significant rise in antibiotic resistance, which is regarded as a great challenge for clinical antibiotic therapy.

[A new member of CMY type cephalosporinase prevailing in Escherichia coli].

OBJECTIVE: To study the resistant phenotype and molecular biology character of plasmid mediated high AmpC-producing clinical isolates of Escherichia coli and to find new AmpC genotype. METHODS: The cefoxitin highly resistant clinical isolates of Escherichia coli were studied by K-B method, three-dimensional method, Isoelectric Focusing (IEF) and the MIC of these strains were examined by micro-dilution method. The conjugation experiment, multiplex PCR and DNA sequencing methods were used in further study. RESULTS: Above 719 strains studied, there are 6 isolates were showed as high AmpC-producing by three-dimensional method and IEF found they could produce a beta-Lactamase which PI was 8.9 and could be inhibited by cloxacillin but not by clavulnate. The strains were resistant to most of third generation cephalosporins, but were susceptible to cefepime, meropenem and imipenem. The experiment also showed that the gene which express this AmpC like beta-Lactamase could be transferable. Multiplex PCR indicated they belong to Citrobacter freundii family. Sequencing of corresponding DNA revealed 99% identities of the deduced amino acid sequence with CMY-2 and CMY-7 respectively. It is a new CMY type cephalosporinase. CONCLUSION: A new CMY type cephalosporinase has been found in clinical strains of Escherichia coli in our hospital. It was resistant to many antibiotics and its resistance could be transferred horizontally.