Microbiological isolates and associated complications of dacryocystitis and canaliculitis in a prominent tertiary ophthalmic teaching hospital in northern China.

BACKGROUND: To report the microbiological isolates, aetiology, complications, antibiotic susceptibilities, and clinical remission of dacryocystitis and canaliculitis in a prominent tertiary ophthalmic teaching and referral hospital located in northern China and to offer appropriate recommendations for preventing and formulating drug treatment strategies. METHODS: This prospective study recruited a total of 477 participants who had been diagnosed with either dacryocystitis or canaliculitis. The cohort comprised 307 patients with chronic dacryocystitis, 111 patients with acute dacryocystitis, and 59 patients with canaliculitis. Purulent discharge from the lacrimal duct was collected using a sterile swab and immediately subjected to microbial culture. Antimicrobial susceptibility testing was conducted following established protocols. All participants were scheduled for follow-up visits within 14 days after receiving antibiotic therapy. RESULTS: The present findings indicated that women exhibited a higher susceptibility to the condition, as evidenced by the occurrence of 367 cases in comparison to 110 cases among men. Among the 477 patients, definitive causes were established in 59 individuals, accounting for 12.4% of the patients. Additionally, ocular complications were reported by 132 patients, representing 27.7% of the total. Monocular involvement was observed in the majority of cases, with 402 out of 477 patients (84.3%) affected, while binocular involvement was present in 75 patients (15.7%). In total, 506 microbiological strains were recovered from 552 eyes, with Staphylococcus epidermidis (16.4%) being the most prevalent microorganism. Other predominant isolates included Corynebacterium macginleyi (9.1%), Staphylococcus aureus (5.1%), Streptococcus pneumoniae (4.9%), Haemophilus (4.4%), Propionibacterium acnes (3.5%), and Eikenella corrodens (3.1%). Among the 12 isolated fungi, Candida parapsilosis accounted for 66.7%. The susceptibility to antimicrobial agents tested in gram-negative bacilli (79.5%) was observed to be higher than that of anaerobic bacteria (76.7%) and gram-positive cocci (55.4%). With pharmacological therapy, the remission rate of acute dacryocystitis (72.7%) was found to be higher than that of canaliculitis (53.3%) and chronic dacryocystitis (42.3%). CONCLUSIONS: This study highlights the microbial spectrum of dacryocystitis and canaliculitis, particularly C.macginleyi, E.corrodens and C.parapsilosis, which are also more frequently isolated. Vancomycin and imipenem may be more effective treatment options. Most cases have an unknown aetiology, and essential preventive measures involve postoperative cleansing of the lacrimal passage following eye and nasal surgeries, as well as the proactive management of rhinitis.

Post-traumatic endophthalmitis caused by streptococcus species in preschool children: clinical features, antibiotic susceptibilities and outcomes.

BACKGROUND/OBJECTIVES: Streptococcus is a common cause of post-traumatic endophthalmitis in children. This study aimed to analyse the clinical features, antibiotic susceptibilities and outcomes of traumatic endophthalmitis caused by streptococcus in preschool children. SUBJECTS/METHODS: Patients aged ≤6 years with traumatic streptococcal endophthalmitis seen at Zhongshan Ophthalmic Center between January 2013 and December 2018 were included in this retrospective study. RESULTS: In total, 21 patients (21 eyes) were included. The mean age of the patients was 3.3 ± 1.7 years, where 57.1% were males. Scissors (28.6%, n = 6) were the most common cause of injury; 86.7% of patients were injured at home. Zone I (80.9%) was the most common wound site; 90.5% of patients presented with a traumatic cataract. In general, Streptococcus pneumoniae (47.6%) was the most common isolate. Viridans group streptococci accounted for 58.3% of cases in children aged 0-3 years, while S. pneumoniae accounted for 66.7% of cases in children aged 4-6 years. The susceptibility rates of streptococcus to cefuroxime, levofloxacin and ofloxacin were 100%, 95.0% and 90.5%, respectively. Although all the patients underwent vitrectomy combined with silicone oil tamponade, the final visual outcomes were no better than counting fingers. CONCLUSIONS: Although S. pneumoniae was the most prevalent organism in general, the dominant species varied between different age groups. The commonly used antibiotics, cefuroxime and fluoroquinolone, showed higher antibiotic susceptibility. Despite prompt treatment, the visual outcomes of paediatric post-traumatic endophthalmitis in preschool children were poor.

Whole genome sequence revealed the fine transmission map of carbapenem-resistant Klebsiella pneumonia isolates within a nosocomial outbreak.

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a major cause of nosocomial infections worldwide. The transmission route of CRKP isolates within an outbreak is rarely described. This study aimed to reveal the molecular characteristics and transmission route of CRKP isolates within an outbreak of nosocomial infection. Methods: Collecting case information, active screening and targeted environmental monitoring were carried out. The antibiotic susceptibility, drug-resistant genes, molecular subtype and whole genome sequence of CRKP strains were analyzed. Results: Between October and December 2011, 26 CRKP isolates were collected from eight patients in a surgical intensive care unit and subsequent transfer wards of Beijing Tongren hospital, China. All 26 isolates harbored blaKPC-2, blaSHV-1, and blaCTX-M-15 genes, had the same or similar pulsed-field gel electrophoresis patterns, and belonged to the sequence type 11 (ST11) clone. By comprehensive consideration of genomic and epidemiological information, a putative transmission map was constructed, including identifying one case as an independent event distinct from the other seven cases, and revealing two transmissions starting from the same case. Conclusions: This study provided the first report confirming an outbreak caused by K. pneumoniae ST11 clone co-harboring the blaKPC-2, blaCTX-M-15, and blaSHV-1 genes, and suggested that comprehensive consideration of genomic and epidemiological data can yield a fine transmission map of an outbreak and facilitate the control of nosocomial transmission.

[The application and epidemiological research of xTAG GPP multiplex PCR in the diagnosis of infectious diarrhea].

OBJECTIVE: To investigate the application value of xTAG (®) gastrointestinal pathogen panel (xTAG9(®) GPP) multiplex PCR in the early diagnosis of infectious diarrhea, and understand the epidemiology of intestinal diarrhea pathogens. METHODS: Five hundred and ninety two specimens were collected in outpatient of Tongren Hospital, Capital Medical University, from 1st Oct 2013 to 30th Sep 2014, comparing the xTAG(®) GPP multiplex PCR assay with the traditional methods (culture, rapid enzyme immunoassay chromatography, microscopic examination, Real-time PCR) and mading the statistical analysis. RESULTS: The positive rate of 592 patients with diarrhea specimens was 47.8% (283/592), the proportion of male and female was 1: 1.02, the average age was 31years. The virus detection rate was 18.1%, Rotavirus A was the most common organism detected (8.8%), concentrated in winter, popular in children.Secondly,Norovirus GI/GII (8.4%),Adenovirus 40/41 was five cases. The positive rate of bacteria was 35.5%, Enterotoxigenic E.coli (8.4%, 50/592) was most frequently detected in summer, common in young adults. The other pathogens were Campylobacter 7.7%, Salmonella 7.0%, Clostridium difficile toxinA/B 3.5%, Shigella 3.3%,E.coli O157 3.3% and Shiga toxin-producing E.coli LT/ST 1.7%.None of Yersinia enterocolitica and Vibrio cholerae was detected. There were ten samples with parasitic (1.7%), five samples were positive for Cryptosporidium, three for Entamoeba histolytica and two for Giardia. All of them did not have obvious distribution followed by season and population. Totally 242(40.8%) infected specimens with single pathogen were detected. There were 41 (6.9%) co-infections samples, including two pathogens 36 cases (6.1%), three pathogens in 5 cases (0.8%). CONCLUSIONS: xTAG(®) GPP multiplex PCR is simple, sensitive, specific and can be used as a quick way to diagnose the infectious diarrhea. Diarrhea pathogen has significant characteristics with the season and crowd.

Application of matrix-assisted laser desorption ionization time-of-flight mass spectrometry in the screening of vanA-positive Enterococcus faecium.

In order to evaluate a rapid matrix-assisted laser desorption ionization-time of flight mass spectrometry (MAIDI-TOF MS) assay in screening vancomycin-resistant Enterococcus faecium, a total of 150 E. faecium clinical strains were studied, including 60 vancomycin-resistant E. faecium (VREF) isolates and 90 vancomycin-susceptible (VSEF) strains. Vancomycin resistance genes were detected by sequencing. E. faecium were identified by MALDI-TOF MS. A genetic algorithm model with ClinProTools software was generated using spectra of 30 VREF isolates and 30 VSEF isolates. Using this model, 90 test isolates were discriminated between VREF and VSEF. The results showed that all sixty VREF isolates carried the vanA gene. The performance of VREF detection by the genetic algorithm model of MALDI-TOF MS compared to the sequencing method was sensitivity = 80%, specificity = 90%, false positive rate =10%, false negative rate =10%, positive predictive value = 80%, negative predictive value= 90%. MALDI-TOF MS can be used as a screening test for discrimination between vanA-positive E. faecium and vanA-negative E. faecium.

MALDI-TOF MS applied to indirect carbapenemase detection: a validated procedure to clearly distinguish between carbapenemase-positive and carbapenemase-negative bacterial strains.

Laboratory identification of carbapenemase-producing clinical isolates is crucial to limit the spread of the bacteria. In this study, we shall first develop the matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) assay in automatic identification of carbapenemase producers. A total of 143 well-characterized isolates were studied. After an incubation of bacteria with meropenem trihydrate, the mixture was centrifuged and the supernatant analyzed by MALDI-TOF MS. A genetic algorithm model with ClinProTools software was built using spectra of 43 carbapenemase-positive isolates and 40 carbapenemase-negative isolates after 2 h of incubation. This model was externally validated using 60 test isolates. All spectra of supernatants of the carbapenemase-negative isolates showed peak profiles comparable to that of pure meropenem (m/z 384.159, 406.140, and 428.122 of its two sodium salt variants) regardless of the incubation time tested. For the carbapenemase-positive isolates, the specific peak for meropenem at m/z 384.159 disappeared during the incubation time, two products of meropenem degradation were identified with m/z 358.18 (the decarboxylated product) and 380.161 (sodium salt of the decarboxylated product), and other degradation products were observed (native molecule with disrupted amide bond with m/z 402.169, three sodium salt variants with m/z 424.151, 446.133, and 468.115). Sixty test isolates were 100% correctly classified as carbapenemase positive and carbapenemase negative with the genetic algorithm model. MALDI-TOF MS coupled with ClinProTools is capable of rapidly, accurately, and automatically identifying carbapenemase producers.

Comparing the transmission potential of Methicillin-resistant Staphylococcus aureus and multidrug-resistant Acinetobacter baumannii among inpatients using target environmental monitoring.

BACKGROUND: With the increasing isolation rate of multidrug-resistant Acinetobacter baumannii (MDR-AB) in China hospitals, more researches focused on its antimicrobial resistance, but few studies reported its nosocomial transmission. In this study, we aim to investigate the transmission features of MDR-AB among inpatients using target environmental monitoring. METHODS: Methicillin-resistant Staphylococcus aureus (MRSA) and MDR-AB active screening and target environmental screening were performed from March 2010 to October 2011 in respiratory intensive care unit (RICU). We compared bed linen contamination rate and acquisition rate of MDR-AB with those of MRSA and analyzed the correlation between weekly colonization pressure adjusted by degree of bed linen contamination (WCPe) and weekly acquisition rate (WAR) of MDR-AB. RESULTS: We found that both the bed linen contamination rate and the acquisition rate of MDR-AB were higher than those of MRSA (χ(2) = 98.081, P < .01; χ(2) = 49.844, P < .01, respectively). The correlation analysis showed positive correlation between MDR-AB WCPe and WAR (rs = 0.560, P < .01). The WCPe and WAR of MDR-AB were higher than those of MRSA (Z = -5.439, P < .01; Z = -3.258, P < .01, respectively). CONCLUSION: Compared with MRSA, MDR-AB carriers showed stronger ability to contaminate their immediate environment, and MDR-AB was easier to transmit among inpatients. Therefore, it was likely more important to perform active environmental monitoring as a method of transmission evaluation and a measure of routine infection control to prevent and control MDR-AB nosocomial transmission more effectively.

Gene therapy of malignant solid tumors by targeting erbB2 receptors and by activating T cells.

One of the strategies to improve the outcome of anti-erbB2-mediated immunotherapy is to combine anti-erbB2 antibodies with T-cell-based adoptive immunotherapy, which can be achieved by expressing anti-erbB2 mAb on the surface of T cells. A single-chain variable fragment (scFv) from an anti-erbB2 mAb has been expressed on T cell surface to bind to erbB2-positive cells, and CD3ζ has been expressed as a fusion partner at C terminus of this scFv to transduce signals. T cells grafted with this chimeric scFv/CD3ζ were able to specifically attack target tumor cells with no MHC/Ag restriction. To test the effects of CD28 signal on cellular activation and antitumor effectiveness of chimeric scFv/CD3ζ-modified T cells, we constructed a recombinant anti-erbB2 scFv/Fc/CD28/CD3ζ gene in a retroviral vector. T cells expressing anti-erbB2 scFv/Fc/CD28/CD3ζ specifically lyzed erbB2-positive target tumor cells and secreted not only interferon-γ (IFN-γ) but also IL-2 after binding to their target cells. Our data indicate that CD3 and CD28 signaling can be delivered in one molecule, which is sufficient for complete T cell activation without exogenous B7/CD28 co-stimulation.

[Risk factors for acquired multidrug-resistant Acinetobacter baumannii colonization in respiratory intensive care unit].

OBJECTIVE: To determine the risk factors for respiratory intensive care unit (RICU)-acquired colonization of multidrug-resistant Acinetobacter baumannii (MDR-AB). METHODS: From January 2010 to June 2011, active screening was performed to define patients with RICU-acquired colonization of MDR-AB. And environment surveillance was carried out and patient data were collected. Logistic regression was applied to identify the risk factors of RICU-acquired colonization of MDR-AB. RESULTS: Active screening for MDR-AB was performed for 110 patients in RICU and 50 patients turned out to be positive. After eliminating 3 input positive patients, the RICU-acquired colonization rate of MDR-AB was 43.9% (47/107). The environmental contaminated rate of MDR-AB was 66.0% (31/47) for 47 positive patients and 33.9% (19/56) for 56 negative ones (χ(2) = 10.494, P < 0.01). Five risk factors were associated with the colonization of MDR-AB through univariate analysis: consciousness disturbance, use of carbapenems, nasal feeding tube, endotracheal intubation and mechanical ventilation (all P < 0.05). The Logistic regression equation contained 3 risk factors of conscious disturbance, use of carbapenems and mechanical ventilation (OR = 3.412, 3.211, 3.002; 95% CI: 1.165 - 9.992, 1.117 - 9.233, 1.101 - 8.182). CONCLUSION: Three risk factors are independently associated with the RICU-acquired colonization of MDR-AB: consciousness disturbance, use of carbapenems and mechanical ventilation.

[Correlation factor analysis of pan-drug resistant Acinetobacter baumannii strains in acquired infections].

OBJECTIVE: To explore the clinical factors, drug resistance and molecular epidemiology homologous characteristics of pan-drug resistant Acinetobacter baumannii (PDRAB) in acquired infections and analyze the correlation factor between epidemic characteristics and acquired infections. METHODS: A total of 60 PDRAB strains from nine acquired infections and related clinic data were collected from January 2009 to January 2011. The drug-resistant phenotype was tested by disk diffusion methods. The isolate identification and homology were studied by automation repetitive-element sequence-based (REP)-PCR typing platform from genes and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-TOF MS) from proteins. RESULTS: All strains were resistant to 12 antibiotics except 2 strains to imipenem and meropenem. The strains in this study were divided into 12 types (A-L) by REP-PCR. And 60 strains were also clustered to a-e types by MALDI-TOF-TOF MS. Compared with MALDI-TOF-TOF MS, REP-PCR tended to be more accurate. Breathing machine carriage and cross transmission were the main reasons for a major epidemic outbreak at department of pulmonary medicine from July 2009 to October 2009. Hand transmission of medical care personnel was a key factor for SICU 2010 January to February. The contamination and transmission to environment of PDRAB in nasal pharynx or respiratory tract by superspreader were the main reasons for the other 7 epidemic outbreaks. Department of emergency medicine was the source of acquired infections. CONCLUSION: The key control measures of acquired infections are early identification and isolation of spreader, environment and instrument disinfection, hand washing and rational uses of antibiotics. MALDI-TOF-TOF MS will become a preferred tool of identification and classification of microorganisms because of its simple operation, affordable price and handling rapidity.

[SOCS1 knockdown sensitize anti-tumor activity of IFN-alpha2a-NGR].

AIM: Search for key molecules to influence the tumor-targeted IFN-alpha2a-NGR anti-tumor sensitivity through signaling pathway study. Try to enhance the antitumor efficacy of IFN-alpha2a-NGR. METHODS: MTT method was used to determine the growth inhibitory effects of IFN-alpha2a-NGR on A549 and MKN-45 cells. Flow cytometry and Western blot were employed to detect the expression of STAT1, p-STAT1, p53, OAS and SOCS1; SOCS1 gene knock down was carried out by synthesized siRNA. RESULTS: When stimulated with IFN-alpha2a-NGR, the increased expression of STAT1, p-STAT1, p53, OAS and SOCS1 were observed in A549 cells, but only SOCS1 was notably increased in MKN-45 cells. The proliferation inhibition ability of MKN-45 to IFN-alpha2a-NGR was promoted by SOCS1 knocking down. (the inhibition rate was enhanced from 14.69%+/-1.05% to 36.97%+/-2.05%). CONCLUSION: This study has further demonstrated that there were no differences on antitumor effects between IFN-alpha2a-NGR and IFN-alpha2a on cell or molecular level. Besides interferon-alpha receptor (IFNAR) which has been demonstrated before, p-STAT1, p53 and SOCS1 were important determinants of tumor resistance to IFNs therapy. The antitumor efficacy of IFN-alpha2a-NGR can be enhanced by RNA interference. These results might be helpful for the further development of IFN-alpha2a-NGR.