Search

Xi Lin,1,2 Junwan Lu,1,2 Changrui Qian,1,2 Hailong Lin,1– 3 Qiaoling Li,1– 3 Xueya Zhang,1– 3 Hongmao Liu,1– 3 Zhewei Sun,1,2 Danying Zhou,1,2 Wei Lu,1,2 Mei Zhu,4 Hailin Zhang,2,3 Teng Xu,5 Kewei Li,1,2 Qiyu Bao,1– 3 Li Lin2,3 1Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education of China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, 325035, People’s Republic of China; 2Institute of Biomedical Informatics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, 325035, People’s Republic of China; 3The Second Affiliated Hospital and Children’s Hospital, Wenzhou Medical University, Wenzhou, 325027, People’s Republic of China; 4Department of Clinical Laboratory, Zhejiang Hospital, Hangzhou, Zhejiang, 310013, People’s Republic of China; 5Institute of Translational Medicine, Baotou Central Hospital, Baotou, 014040, People’s Republic of ChinaCorrespondence: : Li LinThe Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University, Wenzhou, 325027, People’s Republic of ChinaTel +86-577-88002134Email linli97@126.comQiyu BaoInstitute of Biomedical Informatics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, 325035, People’s Republic of ChinaTel/Fax +86-577-86699398Email baoqy@genomics.cnPurpose: An increasing frequency of antibiotic resistance has been observed in both clinical and environmental Aeromonas hydrophila isolates in recent years. However, there are still very few in-depth studies regarding the role of plasmids in the antibiotic resistance of A. hydrophila. Hence, we investigated the molecular and functional characterization of a multidrug-resistant plasmid encoding an NDM-like metallo-β-lactamase, AFM-1, in the clinical A. hydrophila isolate SS332.Methods: The minimum inhibitory concentrations (MICs) of 24 antibiotics against A. hydrophila SS332 were measured by the agar dilution method. The genome of A. hydrophila SS332 was sequenced with PacBio and Illumina platforms. Six plasmid-borne antimicrobial resistance genes were chosen for cloning, including blaAFM-1, blaOXA-1, msr(E), mph(E), aac(6ʹ)-Ib10, and aph(3ʹ)-Ia. Phylogenetic analysis, amino acid sequence alignment, and comparative genomic analysis were performed to elucidate the active site requirements and genetic context of the blaAFM-1 gene.Results: A. hydrophila SS332 showed high levels of resistance to 15 antibiotics, especially those with MIC levels at or above 1024 μg/mL, including ampicillin, cefazolin, ceftriaxone, aztreonam, spectinomycin, and roxithromycin. Six plasmid-borne resistance genes from A. hydrophila were verified to be functional in E. coli DH5α. AFM-1 shared 86% amino acid identity with NDM-1 and showed resistance to ampicillin, cefazolin, cefoxitin, and ceftazidime. In addition, the blaAFM-1 gene was associated with three different novel ISCR19-like elements, designated ISCR19-1, ISCR19-2 and ∆ISCR19-3, which may be involved in the acquisition and mobilization of the blaAFM-1 gene.Conclusion: Our investigation showed that plasmid-borne resistance genes can contribute to antibiotic resistance in A. hydrophila SS332. A novel blaNDM-like gene, blaAFM-1, was verified to be functional and associated with novel ISCR19-like elements. This fact indicated the risk of spread of blaAFM-1 genes and ISCR19-like elements.Keywords: Aeromonas hydrophila, whole-genome sequencing, plasmid-borne resistance genes, blaAFM-1, ISCR19-like elements

To characterize the molecular structure of IncR plasmid-related sequences, comparative genomic analysis was conducted using 261 IncR plasmid backbone-related sequences. Among the sequences, 257 were IncR plasmids including the multidrug-resistance IncR plasmid pR50-74 from Klebsiella pneumoniae strain R50 of this work, and the other four were from bacterial chromosomes. The IncR plasmids were derived from different bacterial genera or species, mainly Klebsiella pneumoniae (70.82%, 182/257), Escherichia coli (11.28%, 29/257), Enterobacter cloacae (7.00%, 18/257), and Citrobacter freundii (3.50%, 9/257). The bacterial chromosomes carrying IncR plasmid backbone sequences were derived from Proteus mirabilis AOUC-001 and Klebsiella pneumoniae KPN1344, among others. The IncR backbone sequence of P. mirabilis AOUC-001 chromosome shows the highest identity with that of pR50-74. Complex class 1 integrons carrying various copies of ISCR1-sdr-qnrB6-△qacE/sul1 (ISCR1-linked qnrB6 unit) were identified in IncR plasmids. In addition to two consecutive copies of qnrB6-qacE-sul1, the other resistance genes encoded on pR50-74 are all related to mobile genetic elements, such as IS1006, IS26, and the class 1 integron. This study provides a clear understanding of the mobility and plasticity of the IncR plasmid backbone sequence and emphasizes the important role of ISCR in the recruitment of multicopy resistance genes.

In analyzing the drug resistance phenotype and mechanism of resistance to macrolide antibiotics of clinical Pseudomonas aeruginosa isolates, the agar dilution method was used to determine the minimum inhibitory concentrations (MICs), and PCR (polymerase chain reaction) was applied to screen for macrolide antibiotics resistance genes. The macrolide antibiotics resistance genes were cloned, and their functions were identified. Of the 13 antibiotics tested, P. aeruginosa strains showed high resistance rates (ranging from 69.5–82.1%), and MIC levels (MIC90 > 256 μg/ml) to macrolide antibiotics. Of the 131 known macrolide resistance genes, only two genes, mphE and msrE, were identified in 262 clinical P. aeruginosa isolates. Four strains (1.53%, 4/262) carried both the msrE and mphE genes, and an additional three strains (1.15%, 3/262) harbored the mphE gene alone. The cloned msrE and mphE genes conferred higher resistance levels to three second-generation macrolides compared to two first-generation ones. Analysis of MsrE and MphE protein polymorphisms revealed that they are highly conserved, with only 1–3 amino acids differences between the proteins of the same type. It can be concluded that even though the strains showed high resistance levels to macrolides, known macrolide resistance genes are seldom present in clinical P. aeruginosa strains, demonstrating that a mechanism other than this warranted by the mphE and msrE genes may play a more critical role in the bacteria’s resistance to macrolides.

The clinical and environmental infections caused by AmpC β-lactamases have been increasingly reported recently. In this study, we characterize the novel chromosome-encoded AmpC β-lactamase SFDC-1 identified in Serratia fonticola strain R28, which was isolated from a rabbit raised on a farm in southern China. SFDC-1 shared the highest amino acid identity of 79.6% with the functionally characterized AmpC β-lactamase gene blaYRC-1 , although it had highly homologous functionally uncharacterized relatives in the same species from different sources, including some of clinical significance. The cloned blaSFDC-1 exhibited resistance to a broad spectrum of β-lactam antibiotics, including most cephalosporins with the highest resistance to ampicillin, cefazolin and ceftazidime, with increased MIC levels ≥128-fold compared with the control strains. The purified SFDC-1 showed catalytic activities against β-lactams with the highest catalytic activity to cefazolin. The genetic context of blaSFDC-1 and its relatives was conserved in the chromosome, and no mobile genetic elements were found surrounding them. This article is protected by copyright. All rights reserved.

Objectives To describe a novel chromosomal aminoglycoside phosphotransferase named APH(3′)-IId identified in an MDR Brucella intermedia ZJ499 isolate from a cancer patient. Methods Species identity was determined by PCR and MALDI-TOF MS analysis. WGS was performed to determine the genetic elements conferring antimicrobial resistance. Gene cloning, transcriptional analysis and targeted gene deletion, as well as protein purification and kinetic analysis, were performed to investigate the mechanism of resistance. Results APH(3′)-IId consists of 266 amino acids and shares the highest identity (48.25%) with the previously known APH(3′)-IIb. Expression of aph(3′)-IId in Escherichia coli decreased susceptibility to kanamycin, neomycin, paromomycin and ribostamycin. The aph(3′)-IId gene in ZJ499 was transcriptionally active under laboratory conditions and the relative abundance of this transcript was unaffected by treatment with the above four antibiotics. However, deletion of aph(3′)-IId in ZJ499 results in decreased MICs of these drugs. The purified APH(3′)-IId showed phosphotransferase activity against kanamycin, neomycin, paromomycin and ribostamycin, with catalytic efficiencies (kcat/Km) ranging from ∼105 to 107 M−1 s−1. Genetic environment and comparative genomic analyses suggested that aph(3′)-IId is probably a ubiquitous gene in Brucella, with no mobile genetic elements detected in its surrounding region. Conclusions APH(3′)-IId is a novel chromosomal aminoglycoside phosphotransferase and plays an important role in the resistance of B. intermedia ZJ499 to kanamycin, neomycin, paromomycin and ribostamycin. To the best of our knowledge, APH(3′)-IId represents the fourth characterized example of an APH(3′)-II enzyme.

Additional file 1: Table S2. Antibiotics resistance profile of all 39 CoNS isolates.

Additional file 1: Table S1. Resistance phenotype and florfenicol resistance genes of the CoNS isolates.

Purpose An increasing frequency of antibiotic resistance has been observed in both clinical and environmental Aeromonas hydrophila isolates in recent years. However, there are still very few in-depth studies regarding the role of plasmids in the antibiotic resistance of A. hydrophila. Hence, we investigated the molecular and functional characterization of a multidrug-resistant plasmid encoding an NDM-like metallo-β-lactamase, AFM-1, in the clinical A. hydrophila isolate SS332. Methods The minimum inhibitory concentrations (MICs) of 24 antibiotics against A. hydrophila SS332 were measured by the agar dilution method. The genome of A. hydrophila SS332 was sequenced with PacBio and Illumina platforms. Six plasmid-borne antimicrobial resistance genes were chosen for cloning, including blaAFM-1, blaOXA-1, msr(E), mph(E), aac(6ʹ)-Ib10, and aph(3ʹ)-Ia. Phylogenetic analysis, amino acid sequence alignment, and comparative genomic analysis were performed to elucidate the active site requirements and genetic context of the blaAFM-1 gene. Results A. hydrophila SS332 showed high levels of resistance to 15 antibiotics, especially those with MIC levels at or above 1024 μg/mL, including ampicillin, cefazolin, ceftriaxone, aztreonam, spectinomycin, and roxithromycin. Six plasmid-borne resistance genes from A. hydrophila were verified to be functional in E. coli DH5α. AFM-1 shared 86% amino acid identity with NDM-1 and showed resistance to ampicillin, cefazolin, cefoxitin, and ceftazidime. In addition, the blaAFM-1 gene was associated with three different novel ISCR19-like elements, designated ISCR19-1, ISCR19-2 and ∆ISCR19-3, which may be involved in the acquisition and mobilization of the blaAFM-1 gene. Conclusion Our investigation showed that plasmid-borne resistance genes can contribute to antibiotic resistance in A. hydrophila SS332. A novel blaNDM-like gene, blaAFM-1, was verified to be functional and associated with novel ISCR19-like elements. This fact indicated the risk of spread of blaAFM-1 genes and ISCR19-like elements.

BackgroundAeromonas hydrophila is a zoonotic and human opportunistic pathogen. Increasing antibiotic resistance profiles have been discovered in both clinical and environmental A. hydrophila isolates in recent years. However, there are still very few in-depth studies regarding the role of plasmids in antibiotic resistance of A. hydrophila. Hence, we investigate the molecular characterization and functional characterization of a multidrug resistant plasmid which encoding a novel NDM variant, AFM-1, in clinical A. hydrophila SS332.MethodsThe minimum inhibitory concentrations (MICs) of 24 antibiotics for A. hydrophila SS332 were measured by the agar dilution method. The genome of A. hydrophila SS332 was sequenced with Pacific and Illumina platforms. Six plasmid-borne antimicrobial resistance genes were chosen for cloning, including blaAFM-1, blaOXA-1, msr(E), mph(E), aac(6')-Ib10, and aph(3')-Ia. Phylogenetic analysis, amino acid sequence alignment, and comparative genomic analysis were performed to elucidate the active site requirements and genetic context of blaAFM-1 gene.ResultsA. hydrophila SS332 showed high levels of resistance to 15 antibiotics, especially those with MIC levels up to or higher than 1024 μg/mL, including ampicillin, cefazolin, ceftriaxone, aztreonam, spectinomycin, roxithromycin. Six plasmid-borne resistance genes were verified to be functional in E. coli DH5α. The blaAFM-1 gene, a novel blaNDM variant, encodes a subclass B1 metallo-β-lactamase AFM-1 which shares 86% amino acid identity with NDM-1. AFM-1 showed resistance to penicillins, cephalosporins and carbapenems. Besides, blaAFM-1 gene was associated with three different novel ISCR19-like elements, designated ISCR19-1, ISCR19-2 and ∆ISCR19-3, which may be involved in the acquisition and mobilization of blaAFM-1 gene. Conclusions Our investigation showed that plasmid-borne resistance genes played a major role in the resistance profiles of A. hydrophila SS332. A novel blaNDM variant, blaAFM-1, was verified to be functional and disseminated among different bacteria species mediated by novel ISCR19-like elements. The fact indicated that the risk of spread of novel resistance genes and novel ISCR elements.

Background: With the wide use of florfenicol to prevent and treat the bacterial infection of domestic animals, the emergence of the florfenicol resistance bacteria is increasingly serious. It is very important to elucidate the molecular mechanism of the bacteria’s resistance to florfenicol.Methods: The minimum inhibitory concentration (MIC) levels were determined by the agar dilution method, and polymerase chain reaction (PCR) was conducted to analyze the distribution of florfenicol resistance genes in 39 CoNS strains isolated from poultry and livestock animals and seafood. The whole genome sequence of one multidrug resistant strain, Staphylococcus lentus H29, was characterized, and comparative genomics analysis of the resistance gene-related sequences was also performed.Results: As a result, the isolates from the animals showed a higher resistance rate (23/28, 82.1%) and much higher MIC levels to florfenicol than those from seafood. Twenty-seven animal isolates carried 37 florfenicol resistance genes (including 26 fexA, 6 cfr and 5 fexB genes) with one carrying a cfr gene, 16 each harboring a fexA gene, 5 with both a fexA and a fexB genes and the other 5 with both a fexA and a cfr genes. On the other hand, all 11 isolates from seafood were sensitive to florfenicol, and only 3 carried a fexA gene each. The whole genome sequence of S. lentus H29 was composed of a chromosome and two plasmids (pH29-46, pH29-26) and harbored 11 resistance genes, including 6 genes [cfr, fexA, ant(6)-Ia, aacA-aphD, mecA and mph(C)] encoded on the chromosome, 4 genes [cfr, fexA, aacA-aphD and tcaA] on pH29-46 and 1 gene (fosD) on pH29-26. We found that the S. lentus H29 genome carried two identical copies of the gene arrays of radC-tnpABC-hp-fexA (5,671 bp) and IS256-cfr (2,690 bp), of which one copy of the two gene arrays was encoded on plasmid pH29-46, while the other was encoded on the chromosome.Conclusions: The current study revealed the wide distribution of florfenicol resistance genes (cfr, fexA and fexB) in animal bacteria, and to the best of our knowledge, this is the first report that one S. lentus strain carried two identical copies of florfenicol resistance-related gene arrays.

A self-designed Ti-35421 (Ti-3Al-5Mo-4Cr-2Zr-1Fe wt%) titanium alloy is a new type of low-cost high strength titanium alloy. In order to understand the hot deformation behavior of Ti-35421 alloy, isothermal compression tests were carried out under a deformation temperature range of 750–930 °C with a strain rate range of 0.01–10 s−1 in this study. Electron backscatter diffraction (EBSD) was used to characterize the microstructure prior to and post hot deformation. The results show that the stress–strain curves have obvious yielding behavior at a high strain rate (>0.1 s−1). As the deformation temperature increases and the strain rate decreases, the α phase content gradually decreases in the α + β phase region. Meanwhile, spheroidization and precipitation of α phase are prone to occur in the α + β phase region. From the EBSD analysis, the volume fraction of recrystallized grains was very low, so dynamic recovery (DRV) is the dominant deformation mechanism of Ti-35421 alloy. In addition to DRV, Ti-35421 alloy is more likely to occur in continuous dynamic recrystallization (CDRX) than discontinuous dynamic recrystallization (DDRX).

BackgroundWith the wide use of florfenicol to prevent and treat the bacterial infection of domestic animals, the emergence of the florfenicol resistance bacteria is increasingly serious. It is very important to elucidate the molecular mechanism of the bacteria’s resistance to florfenicol.MethodsThe minimum inhibitory concentration (MIC) levels were determined by the agar dilution method, and polymerase chain reaction was conducted to analyze the distribution of florfenicol resistance genes in 39 CoNS strains isolated from poultry and livestock animals and seafood. The whole genome sequence of one multidrug resistant strain,Staphylococcus lentusH29, was characterized, and comparative genomics analysis of the resistance gene-related sequences was also performed.ResultsAs a result, the isolates from the animals showed a higher resistance rate (23/28, 82.1%) and much higher MIC levels to florfenicol than those from seafood. Twenty-seven animal isolates carried 37 florfenicol resistance genes (including 26fexA, 6cfrand 5fexBgenes) with one carrying acfrgene, 16 each harboring afexAgene, 5 with both afexAgene and afexBgene and the other 5 with both afexAgene and acfrgene. On the other hand, all 11 isolates from seafood were sensitive to florfenicol, and only 3 carried afexAgene each. The whole genome sequence ofS. lentusH29 was composed of a chromosome and two plasmids (pH29-46, pH29-26) and harbored 11 resistance genes, including 6 genes [cfr, fexA, ant(6)-Ia,aacA-aphD, mecAandmph(C)] encoded on the chromosome, 4 genes [cfr, fexA, aacA-aphDandtcaA] on pH29-46 and 1 gene (fosD) on pH29-26. We found that theS. lentusH29 genome carried two identical copies of the gene arrays ofradC-tnpABC-hp-fexA(5671 bp) and IS256-cfr(2690 bp), of which one copy of the two gene arrays was encoded on plasmid pH29-46, while the other was encoded on the chromosome.ConclusionsThe current study revealed the wide distribution of florfenicol resistance genes (cfr, fexAandfexB) in animal bacteria, and to the best of our knowledge, this is the first report that oneS. lentusstrain carried two identical copies of florfenicol resistance-related gene arrays.

BACKGROUND Previously reported data has guided the treatment and prevention of blindness. This study aimed to evaluate the current prevalence and causes of visual impairment among adults who were 50 years old and older in the Binhu District of Wuxi City, China. MATERIAL AND METHODS A randomized sample of stratified clusters was used to analyze individuals from 30 basic sampling units in Wuxi Binhu District. Visual impairment was defined according to World Health Organization (WHO) standards. RESULTS A total of 6725 people who were at least 50 years old participated in this study. According to WHO standards, bilateral low vision and blindness prevalence were both higher in women than in men (low vision: 6.5% vs. 5.2%; and blindness: 1.4% vs. 0.8%; P=0.022 and P=0.039, respectively). The incidence of bilateral visual impairment increased significantly with age (P

The genusCitrobacteris an opportunistic pathogen causing infections in animals, and the published data for its resistance to florfenicol are scarce. In this study, we investigated the antimicrobial susceptibility and molecular characteristics of florfenicol resistance genes amongCitrobacterisolates from animal and relevant environmental samples and conducted a comparative analysis of a multidrug-resistantCitrobacter freundiistrain isolated from a rabbit. Among 20Citrobacterstrains isolated from animal samples, resistance was most commonly observed to ampicillin (100%), tetracycline (75%), streptomycin (65%), florfenicol (60%), chloramphenicol (60%), and aztreonam (50%), while all the strains found in environmental samples were resistant to few antibiotics. The florfenicol resistance genefloRwas detected in 12 isolates (48%, 12/25) from animal samples, and all of thefloR-positive isolates were resistant to florfenicol with minimum inhibitory concentration (MIC) values ≥256 μg/mL. Sequencing and comparative analysis of the plasmids from a multidrug-resistantC. freundiiisolate named R47 showed that thefloR-containing region in the plasmid pR47-54 was a truncated transposon-like structure and could be found on both plasmids and chromosomes of bacteria of either animal or human origin. Furthermore, a range of antimicrobial and metal resistance genes associated with mobile genetic elements could be identified in pR47-54 and the other plasmid pR47-309 ofC. freundiiR47. These results provide in-depth views into the phenotypic and molecular characteristics ofCitrobacterisolates recovered from animal and relevant environmental samples, as well as highlight the role horizontal gene transfer plays in the dissemination of plasmid-encoded resistance genes.

Due to the inappropriate use of florfenicol in agricultural practice, florfenicol resistance has become increasingly serious. In this work, we studied the novel florfenicol resistance mechanism of an animal-derived Leclercia adecarboxylata strain R25 with high-level florfenicol resistance. A random genomic DNA library was constructed to screen the novel florfenicol resistance gene. Gene cloning, gene knockout, and complementation combined with the minimum inhibitory concentration (MIC) detection were conducted to determine the function of the resistance-related gene. Sequencing and bioinformatics methods were applied to analyze the structure of the resistance gene-related sequences. Finally, we obtained a regulatory gene of an RND (resistance-nodulation-cell division) system, ramA, that confers resistance to florfenicol and other antibiotics. The ramA-deleted variant (LA-R25ΔramA) decreased the level of resistance against florfenicol and several other antibiotics, while a ramA-complemented strain (pUCP24-prom-ramA/LA-R25ΔramA) restored the drug resistance. The whole-genome sequencing revealed that there were five RND efflux pump genes (mdtABC, acrAB, acrD, acrEF, and acrAB-like) encoded over the chromosome, and ramA located upstream of the acrAB-like genes. The results of this work suggest that ramA confers resistance to florfenicol and other structurally unrelated antibiotics, presumably by regulating the RND efflux pump genes in L. adecarboxylata R25.

"AIM: To investigate the prevalence and risk factors of age-related cataract (ARC), ARC surgery procedures, and postoperative vision results among adults over 50 years old in the Binhu District of Wuxi City, China. METHODS: Thirty basic sampling units were analyzed via a cluster random sampling method. Detailed medical histories were collected and eye examinations were performed. Cataract prevalence and surgical procedures were quantified. RESULTS: Among the 6150 participants, 1421 cataract cases were diagnosed and prevalence was 23.1%. The prevalence of cortical, nuclear, and posterior subcapsular cataracts increased with age (P0.05). The odds ratio of cataract patients who had or did not have cataract surgery was 3.15 (87/28) and the frequency of cataract blindness surgery was 75.7% (87/115). Poor visual outcomes was in 107 eyes (40.7%) after cataract surgery. Poor vision was mostly caused by uncorrected reflective errors (30.9%) and ocular comorbidities (41.1%). The prevalence of cataract surgery complications was 5.7% (15/263). Surgical complications and posterior capsular opacification were avoidable factors facilitating poor vision. CONCLUSION: ARC, especially in females and illiterate individuals, presents a public health problem in this district. Poor visual outcomes after cataract surgery are frequent. High-quality cataract surgeries and treatment of ocular comorbidities are vital. "

The isothermal hot compression behavior of new Ti&ndash, Fe&ndash, B (named as TF400) alloy was investigated in the temperature range of 750&ndash, 950 &deg, C and strain rate range from 0.01 to 10 s&minus, 1 with the maximum height reduction of 60% by using a Gleeble 3800 thermal simulator. By considering the effect of strain via variable material parameters, a modified constitutive model was proposed to accurately predict the flow stress. The predicted results demonstrate that the flow stress decreases with the increase of temperature while it increases as the strain rate increases, in good agreement with the present experimental results. A mechanistic understanding of plastic deformation behavior in the TF400 alloys was developed by inspecting the microstructural characteristics prior to and after deformations. Dynamic recrystallization and dynamic transformation were found to be the dominant restoration mechanism during the hot deformation process.

A [3-t-Bu-2-OC6H3CHN(C6F5)]2TiCl2 catalyst (bis(phenoxyimine)titanium dichloride complex – FI catalyst) was immobilized on disilanolisobutyl polyhedral oligomeric silsesquioxane (OH-POSS) to prepare ultrahigh molecular-weight polyethylene (UHMWPE)/polyhedral oligomeric silsesquioxane (POSS) nanocomposites during ethylene in situ polymerization. The dispersion state of POSS in the UHMWPE matrix was characterized by X-ray diffraction measurements and transmission electron microscopy. It was shown that the OH-POSS achieved uniformed dispersion in the UHMWPE matrix, although its polarity was unmatched. The isothermal and nonisothermal crystallization behavior of the nanocomposites was investigated by means of differential scanning calorimetry. The crystallization rate of the nanocomposites was enhanced because of the incorporation of POSS during the isothermal crystallization. POSS acted as a nucleus for the initial nucleation and the subsequent growth of the crystallites. For nonisothermal studies, POSS showed an increase in the crystallinity. The crystallization rate of the nanocomposites decreased because the presence of POSS hindered the crystal growth. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40847.