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.

[Study on the etiological characteristics and prevention and control of adult community-acquired pneumonia in hospitalized patients in a hospital in Beijing from 2015 to 2019]

Objective: To explore the distribution characteristics of pathogens in adult patients with community-acquired pneumonia (CAP) and to provide basis for the diagnosis, treatment, prevention of CAP. Methods: 1 446 inpatients with CAP were prospectively enrolled in a third-class hospital in Beijing in recent 5 years (from January 2015 to December 2019). Respiratory tract samples were collected for smear, culture, nucleic acid, antigen and antibody detection to identify the pathogen of CAP. Mann-Whitney U test was used for continuous variables and χ² test or Fisher's exact test was used for categorical data for statistical analysis. Results: Among the 1 446 patients, 822 (56.85%) patients were infected with a single pathogen, 231 (15.98%) patients were infected with multiple pathogens, and 393 (27.18%) patients were not clear about the pathogen. Influenza virus is the first pathogen of CAP (20.95%, 303/1 446), mainly H1N1 (8.51%, 123/1 446), followed by mycoplasma pneumoniae (7.19%, 104/1 446), Mycobacterium tuberculosis (5.33%, 77/1 446) and Streptococcus pneumoniae (5.05%, 73/1 446). The outbreak of H1N1 occurred from December 2018 to February 2019, and the epidemic of mycoplasma pneumoniae pneumonia was monitored from August to November 2019. Patients under 65 years old had high detection rates of Mycoplasma pneumoniae (14.41% vs. 2.41%, χ²=74.712,P<0.001), Streptococcus pneumoniae (8.16% vs. 2.99%, χ²=18.156, P<0.001), rhinovirus (6.08% vs. 3.56%, χ²=5.025, P<0.025), Chlamydia pneumoniae (5.90% vs. 1.15%, χ²=26.542, P<0.001) and adenovirus (3.13% vs. 0.92%, χ²=9.547, P=0.002). The severe disease rate of CAP was 14.66% (212/1 446), and the average mortality rate was 3.66% (53/1 446). The severe illness rate and mortality rate of bacterial-viral co-infection were 28.97% (31/107) and 19.63% (21/107), respectively. Conclusions: Influenza virus is the primary pathogen of adult CAP. Outbreaks of Mycoplasma pneumoniae and H1N1 were detected in 2018 and 2019, respectively. The remission rate and mortality rate of virus-bacteria co-infection were significantly higher than those of single pathogen infection. Accurate etiological basis not only plays a role in clinical diagnosis and treatment, but also provides important data support for prevention and early warning.

[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.

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.

[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.

[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.