Ocular bacterial infections at a tertiary eye center in China: a 5-year review of pathogen distribution and antibiotic sensitivity.

AIM: To provide statistical evidence for the use of antibiotics in ophthalmology by assessing the distribution and antibiotic sensitivity of bacterial isolates from ocular specimens with suspected microbial infections. METHODS: This study applied a retrospective analysis of 3690 bacterial isolates from ocular specimens, which were obtained from the conjunctiva, cornea, aqueous humor, vitreous body, and other ocular sites of the patients at Shandong Eye Institute in northern China from January 2013 to December 2017. The parameters assessed mainly included the distribution of isolated bacteria and the results of susceptibility tests for antibiotics. In the analysis of antibiotic sensitivities, the bacteria were divided into four groups according to gram staining, and statistical methods were used to compare their antibiotic sensitivities. RESULTS: Among the 3690 isolated bacterial strains, Staphylococcus epidermidis (2007, 54.39%) accounted for the highest proportion. As for the total isolates, their sensitivity rate to gatifloxacin was up to 90.01%, with four types of gram-stained bacteria being all highly sensitive to it, but their sensitivity rate to levofloxacin was only 51.91%. The sensitivity rate of gram-negative bacilli (G-B) to levofloxacin was 83.66%, significantly higher than the other three types of gram-stained bacteria (P<0.05). Gram-positive cocci (G+C, 97.95%) and gram-positive bacilli (G+B, 97.54%) were more sensitive to vancomycin than gram-negative cocci (G-C, 70.59%) and G-B (68.57%; P<0.05). For fusidic acid, the sensitivity rates of G+C (89.83%) and G+B (73.37%) were significantly higher than that of G-B (29.83%; P<0.05). The gram-negative bacteria's sensitivity rate to cefuroxime was as low as 59.25%, but only G-B was less sensitive to cefuroxime (57.28%), while G-C was still highly sensitive (89.29%). The sensitivity rate of gram-positive bacteria to moxifloxacin was as high as 80.28%, but only G+C was highly sensitive to moxifloxacin (81.21%), while G+B was still less sensitive (32.00%). CONCLUSION: Staphylococcus epidermidis is the predominant isolate in all ocular specimens with bacteria. Gatifloxacin is more suitable for topical prophylactic use than levofloxacin in ophthalmology when necessary. Vancomycin and fusidic acid both have better effects on gram-positive bacteria than gram-negative bacteria. More accurate antibiotic sensitivity analysis results can be obtained when a more detailed bacterial classification and more appropriate statistical methods are performed.

Construction of (3,6)-connected polyoxometalate-based metal-organic frameworks (POMOFs) from triangular carboxylate and dimerized Zn4-ε-Keggin.

Using the methodology of extension of reduced transition metal-grafted ε-Keggin polyoxoanions with two types of terphenyl-based tricarboxylates of H3L1 (3,5',3''-position substitution) and H3L2 (4,5',4''-position substitution) we isolated two (3,6)-connected 3D polyoxometalate-based metal-organic frameworks, [TBA]3[H3PMo12O40][Zn4L2] (1, YZU-105), and [TPA]3[H3PMo12O40][Zn4L1]·0.5H2O (2, YZU-106) (H3L1 = [1,1';3',1''-terphenyl]-3,5',3''-tricarboxylic acid; H3L2 = [1,1';3',1''-terphenyl]-4,5',4''-tricarboxylic acid; TBA = tetrabutylammonium; TPA = tetrapropylammonium). In both compounds, the building block was the dimerized form of Zn4-{ε-H3PMo12O40}. Such dimerization left six anchoring points for each dimer and, as a result, a 6-connected node was formed. Compounds 1 and 2 exhibited topologies of (4·85)3(4·82)6 and (65·10)3(63)6, respectively. This work illustrates that use of tri-carboxylate substitutions in different positions (3,5',3''-position/4,5',4''-position) in tripodal terphenyl-based ligands allows different extents of twisting of the peripheral aromatic ring with respect to the central ring, thereby giving rise to different extending directions and symmetries.

[HBV genotypes distribution and YMDD spontaneous mutation in Qingdao population].

OBJECTIVE: To investigate the distribution of hepatitis B virus (HBV) genotypes in Qingdao, and the relationship of HBV genotypes with the serum HBV-DNA levels and HBV YMDD spontaneous mutation of patients, then to discuss the clinical significance. METHODS: Hepatitis B virus genotypes and YMDD spontaneous mutation of 144 patients were detected by real time PCR (Taqman probe), then the results were analyzed by statistical method. RESULTS: Of the 144 patients, 130 (90.3%) were genotype C, 12 (8.3%) were genotype B, and 2 (1.4%) were neither genotype B nor genotype C; 33 (22.9%) were detected to have YMDD mutation, and 25 (75.5%) were YVDD positive, 3 (9.1%) were YIDD positive, 5 (15.2%) were YVDD and YIDD positive. There were no significant differences between clinical diagnosis, serum HBV-DNA levels, YMDD spontaneous mutation and HBV genotypes (P > 0.05). CONCLUSION: Genotype C is the dominant position for HBV genotype in Qingdao. Untreated patients with chronic hepatitis B have YMDD spontaneous mutation. HBV genotypes have no association with YMDD spontaneous mutation and the development of diseases.

[Relationship between polymorphism sites of IRF5, TLR-9 and SLE patients in Shandong Han population].

OBJECTIVE: To investigate two single nucleotide polymorphism sites of IRF5 and TLR-9 and to detect their relationship with SLE (systemic lupus erythematosus) in a Han population from Shandong province. METHODS: The polymorphisms of rs2004640 G/T, rs10954213 G/A in IRF-5 and rs187084C/T, rs352139A/G in TLR-9 were detected with PCR-RFLP in 92 cases of SLE and 88 healthy controls. The genotype and allele frequencies were calculated and analyzed. RESULTS: (1) The genotype frequencies of GG, GT and TT in rs2004640 site in SLE were 0.198, 0.521 and 0.281 respectively. The difference was significant between SLE and controls (chi(2) = 8.73, P < 0.05); the genotype frequencies of GG, GA and AA at rs109542130 site in SLE were 0.318, 0.409 and 0.273 respectively. The difference was significant between SLE and controls (chi(2) = 6.36, P < 0.05). (2) The genotype frequencies of CC, CT and TT at rs187084 site in SLE were 0.185, 0.413 and 0.402 respectively. There was no difference between SLE and controls (chi(2) = 2.99, P > 0.05); the genotype frequencies of AA, AG and GG at rs352139 site in SLE were 0.228, 0.533 and 0.239 respectively. There was no difference between SLE and controls (chi(2) = 4.54, P > 0.05). CONCLUSION: The polymorphism of rs2004640 and rs10954213 in IRF5 may be associated with SLE in the population of Han nationality from Shandong province. However, the polymorphism of rs187084 and rs352139 in TLR-9 is not associated with SLE.

Analysis of adaptive mutations in Kunjin virus replicon RNA reveals a novel role for the flavivirus nonstructural protein NS2A in inhibition of beta interferon promoter-driven transcription.

The establishment of persistent noncytopathic replication by replicon RNAs of a number of positive-strand RNA viruses usually leads to generation of adaptive mutations in nonstructural genes. Some of these adaptive mutations (e.g., in hepatitis C virus) increase the ability of RNA replication to resist the antiviral action of alpha/beta interferon (IFN-alpha/beta); others (e.g., in Sindbis virus) may also lead to more efficient IFN production. Using puromycin-selectable Kunjin virus (KUN) replicon RNA, we identified two adaptive mutations in the NS2A gene (producing Ala30-to-Pro and Asn101-to-Asp mutations in the gene product; for simplicity, these will be referred to hereafter as Ala30-to-Pro and Asn101-to-Asp mutations) that, when introduced individually or together into the original wild-type (wt) replicon RNA, resulted in approximately 15- to 50-fold more efficient establishment of persistent replication in hamster (BHK21) and human (HEK293 and HEp-2) cell lines. Transfection with a reporter plasmid carrying the luciferase gene under the control of the IFN-beta promoter resulted in approximately 6- to 7-fold-higher luciferase expression in HEp-2 cells stably expressing KUN replicon RNA with an Ala30-to-Pro mutation in the NS2A gene compared to that observed in HEp-2 cells stably expressing KUN replicon RNA with the wt NS2A gene. Moreover, cotransfection of plasmids expressing individual wt or Ala30-to-Pro-mutated NS2A genes with the IFN-beta promoter reporter plasmid, followed by infection with Semliki Forest virus to activate IFN-beta promoter-driven transcription, showed approximately 7-fold inhibition of luciferase expression by the wt but not by the Ala30-to-Pro-mutated NS2A protein. The results show for the first time a role for the flavivirus nonstructural protein NS2A in inhibition of IFN-beta promoter-driven transcription and identify a single-amino-acid mutation in NS2A that dramatically reduces this inhibitory activity. The findings determine a new function for NS2A in virus-host interactions, extend the range of KUN replicon vectors for noncytopathic gene expression, and identify NS2A as a new target for attenuation in the development of live flavivirus vaccines.

Molecular and functional analyses of Kunjin virus infectious cDNA clones demonstrate the essential roles for NS2A in virus assembly and for a nonconservative residue in NS3 in RNA replication.

A number of full-length cDNA clones of Kunjin virus (KUN) were previously prepared; it was shown that two of them, pAKUN and FLSDX, differed in specific infectivities of corresponding in vitro transcribed RNAs by approximately 100,000-fold (A. A. Khromykh et al., J. Virol. 72:7270-7279, 1998). In this study, we analyzed a possible genetic determinant(s) of the observed differences in infectivity initially by sequencing the entire cDNAs of both clones and comparing them with the published sequence of the parental KUN strain MRM61C. We found six common amino acid residues in both cDNA clones that were different from those in the published MRM61C sequence but were similar to those in the published sequences of other flaviviruses from the same subgroup. pAKUN clone had four additional codon changes, i.e., Ile59 to Asn and Arg175 to Lys in NS2A and Tyr518 to His and Ser557 to Pro in NS3. Three of these substitutions except the previously shown marker mutation, Arg175 to Lys in NS2A, reverted to the wild-type sequence in the virus eventually recovered from pAKUN RNA-transfected BHK cells, demonstrating the functional importance of these residues in viral replication and/or viral assembly. Exchange of corresponding DNA fragments between pAKUN and FLSDX clones and site-directed mutagenesis revealed that the Tyr518-to-His mutation in NS3 was responsible for an approximately 5-fold decrease in specific infectivity of transcribed RNA, while the Ile59-to-Asn mutation in NS2A completely blocked virus production. Correction of the Asn59 in pAKUN NS2A to the wild-type Ile residue resulted in complete restoration of RNA infectivity. Replication of KUN replicon RNA with an Ile59-to-Asn substitution in NS2A and with a Ser557-to-Pro substitution in NS3 was not affected, while the Tyr518-to-His substitution in NS3 led to severe inhibition of RNA replication. The impaired function of the mutated NS2A in production of infectious virus was complemented in trans by the helper wild-type NS2A produced from the KUN replicon RNA. However, replicon RNA with mutated NS2A could not be packaged in trans by the KUN structural proteins. The data demonstrated essential roles for the KUN nonstructural protein NS2A in virus assembly and for NS3 in RNA replication and identified specific single-amino-acid residues involved in these functions.