Circular RNA hsa_circ_0049657 as a Potential Biomarker in Non-Small Cell Lung Cancer.

Non-small cell lung cancer (NSCLC) is a common lung disorder. In this study, we applied bioinformatics methods to analyze and investigate the role of the NFIX gene in NSCLC. Hsa_circ_0049657 is derived from the NFIX gene, this research aimed to verify the potential role of hsa_circ_0049657 in the development of NSCLC. The results suggested that NFIX was downregulated in most cancers. In addition, the NFIX expression in lung adenocarcinoma (LUAD) was associated with the clinicopathological stage. In LUAD, NFIX expression was associated with the degree of infiltration of most immune cells. The expression levels of hsa_circ_0049657 were significantly lower in cancerous tissues than in paracancerous tissues. Moreover, the results showed that hsa_circ_0049657 expression was downregulated in NSCLC cells. After overexpression of hsa_circ_0049657, the proliferation and migration ability of NSCLC cells were significantly inhibited and the level of apoptosis was increased. We could suppress the proliferation and invasion abilities and promote apoptosis of NSCLC cells by up-regulating hsa_circ_0049657, which might be a potential biomarker for NSCLC.

MALAT1 Polymorphisms and Lung Cancer Susceptibility in a Chinese Northeast Han Population.

Background: LncRNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) was competitive endogenous RNA (ceRNA) involved in various molecular processes for metastasis development in lung cancer. Single nucleotide polymorphisms (SNPs) in MALAT1 gene might be predictive markers for lung cancer. In our study, we selected rs619586 and rs3200401 in MALAT1 gene to explore their effects on lung cancer susceptibility. Methods: The case-control study included 444 lung cancer cases and 460 healthy controls. Genotyping was performed by Taqman allelic discrimination method. Logistic regression, Student t-test, and Chi-square test (χ2 ) were used to analyze the data. Results: The findings of the study showed that rs3200401 was significantly associated with the risk of non-small cell lung cancer (NSCLC) and lung squamous cell carcinoma (LUSC). Compared with homozygous CC genotype, CT heterozygous genotype decreased risk of NSCLC (Pa = 0.034) and LUSC (Pa = 0.025). In addition, no statistical association was detected between rs619586 and lung cancer susceptibility. The interactions between genes and cigarette smoking were discovered via crossover analysis. However, there were no remarkable gene-environment interactions in additive and multiplicative model. Conclusion: Rs3200401 in lncRNA MALAT1 was associated with the susceptibility of non-small-cell lung cancer and lung squamous cell carcinoma. The gene-environmental (cigarette smoking) interactions were not notable.

Association of LINC00673 rs11655237 polymorphism with cancer susceptibility: A meta-analysis based on 23,478 subjects.

BACKGROUND: Some studies on the relationship between LINC00673 polymorphism and cancer susceptibility have been inconsistent. To perform a more comprehensively quantitative assessment of LINC00673 rs11655237 and risk of overall cancer, we operated this meta-analysis for the first time. METHODS: A comprehensive search was conducted to obtain relevant literature up to November 20, 2019. Pooled odds ratios and 95% confidence intervals were utilized to assess rs11655237 and cancer susceptibility under five different genetic models. RESULTS: Eventually, 11 case-control studies from 9 articles were included. We found that LINC00673 rs11655237 polymorphism increased the susceptibility to overall cancer under all genetic models in the overall population. By dividing ethnicity and cancer type into subgroups, we also obtained similar positive results in subgroups of Chinese population, pancreatic cancer, cervical cancer, neuroblastoma, hepatoblastoma and gastric cancer. CONCLUSION: Overall, this meta-analysis has demonstrated for the first time that LINC00673 rs11655237 could increase susceptibility to cancer.

Association between polymorphism in CDKN2B-AS1 gene and its interaction with smoking on the risk of lung cancer in a Chinese population.

BACKGROUND: Long non-coding RNAs became the hot spots in the carcinogenesis of various tumors. This case-control study evaluated the association between the rs2151280 in lncRNA CDKN2B-AS1 and lung cancer risk. METHODS: This study included 507 lung cancer patients and 542 healthy individuals. Odds ratios and their 95% confidence intervals were calculated by unconditional logistic regression analysis to evaluate the association between the rs2151280 and lung cancer risk. RESULTS: Compared with individuals carrying TT genotype, individuals carrying CC genotype of rs2151280 had a decreased risk of lung cancer (OR = 0.640, 95%CI = 0.421-0.972, P = 0.036). In the recessive model, rs2151280 CC genotype was observed to reduce the risk of lung cancer (OR = 0.684). C allele was associated with non-small cell lung cancer risk (OR = 0.674). The rs2151280 was significantly associated with lung adenocarcinoma risk (CCvsTT: OR = 0.567, 95%CI = 0.333-0.965, P = 0.037; CCvsTC+TT: OR = 0.543, 95%CI 0.330-0.893, P = 0.016, respectively). However, there was no significant association between rs2151280 and lung squamous cell carcinoma risk in five models. The quantitative analysis suggested that there were no significant interactions of rs2151280 with smoking exposure to lung cancer susceptibility. CONCLUSIONS: This hospital-based case-control study suggested that CDKN2B-AS1 rs2151280 T>C was associated with the risk of lung cancer.

The Association Between Two Common Polymorphisms and Cancer Susceptibility: A Meta-Analysis.

BACKGROUND: Most studies revealed that microRNAs could play important roles in the development of various types of cancers. However, the findings remain inconsistent and controversial. To get more accurate results about the association of miR-26a-1 rs7372209 and miR-423 rs6505162 polymorphisms with risk of cancer, we conduct this meta-analysis. MATERIALS AND METHODS: We have searched relevant articles from the PubMed, Web of Science, Wanfang, and Chinese National Knowledge Infrastructure databases up to May 3, 2019. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were analyzed to assess the relationship between these two genetic polymorphisms and susceptibility to cancer. All statistical analyses were performed with Stata 12.0 software. RESULTS: Thirty-five articles were eligible in this meta-analysis, including 17,746 cases and 21,808 controls. Our results suggested that the miR-26a-1 rs7372209 polymorphism was associated with the susceptibility to overall cancer significantly in homozygote comparison and recessive model (TT versus CC: OR = 1.167, 95% CI: 1.025-1.329, P = 0.020; TT versus CT + CC: OR = 1.162, 95% CI: 1.025-1.318, P = 0.019). For miR-423 rs6505162, this study showed that the relationship between it and overall cancer susceptibility was statistically significant among five genetic models (CA versus CC: OR = 0.884, 95% CI: 0.806-0.969, P = 0.009; AA + CA versus CC: OR = 0.870, 95% CI: 0.789-0.959, P = 0.005; AA versus CA + CC: OR = 0.904, 95% CI: 0.827-0.988, P = 0.026; A versus C: OR = 0.899, 95% CI: 0.834-0.970, P = 0.006) rather than homozygote model. CONCLUSIONS: Rs7372209 in miR-26a-1 and rs6505162 in miR-423 are associated with overall cancer susceptibility.

Identification and Characterization of Cronobacter Strains Isolated from Environmental Samples.

As an emerging food-borne pathogen, Cronobacter species are ubiquitous in the food and environment. In order to know the characteristics of Cronobacter spp. from the environment, we isolated Cronobacter spp. from soil and water, and then studied the molecular typing and antibiotic resistance characteristics of these isolates. In 2016, 141 soil and water samples were collected from farms and Riverside Park in Beijing. Isolates were identified by real-time PCR, 16s rRNA sequencing, and whole-genome sequencing. Molecular subtyping of these isolates was characterized by pulsed-field gel electrophoresis, multilocus sequence typing (MLST), and antibiotic susceptibility tests. Cronobacter species were classified based on fusA sequencing. Twenty-two samples (15.60%) contained Cronobacter spp., and four species were detected, i.e., C. dubliniensis (n = 10), C. sakazakii (n = 6), C. turicensis (n = 4), and C. malonaticus (n = 2). For MLST, 12 types (ST519-ST525, ST533-ST537) were newly identified, indicating high diversity. Most isolates (68.18%) showed resistance to cefazolin. Siccibacter turicensis and Cronobacter both with blue-green colonies on selective media should be respectively identified. Apparently, major Cronobacter species in soil and water samples differed from those in food. Molecular subtyping showed that the environment could not be excluded as a source of Cronobacter infection. The resistance to cefazolin of most isolates indicated natural resistance.

Polymorphism in lncRNA AC016683.6 and its interaction with smoking exposure on the susceptibility of lung cancer.

BACKGROUND: Long non-coding RNAs play pivotal roles in the carcinogenesis of multiple types of cancers. This study is firstly to evaluate influence of rs4848320 and rs1110839 polymorphisms in long non-coding RNA AC016683.6 on the susceptibility of lung cancer. METHODS: The present study was a hospital-based case-control study with 434 lung cancer patients and 593 cancer-free controls. Genotyping of the two SNPs detected by Taqman® allelic discrimination method. RESULTS: There were no statistically significant associations between rs4848320 and rs1110839 polymorphisms in AC016683.6 and risk of lung cancer in overall population. However, in the smoking population, rs4848320 and rs1110839 polymorphisms significantly increased the risk of lung cancer in dominant and homozygous models (Rs4848320: P = 0.029; Rs1110839: P = 0.034), respectively. In male population, rs1110839 genetic variant was related to the risk of lung cancer in all genetic models (GG vs. TT: P = 0.008; Dominant model: P = 0.029; Recessive model: P = 0.027) rather than heterozygous model. The crossover analyses provided rs4848320 and rs1110839 risk genotypes carriers combined with smoking exposure 2.218-fold, 1.755-fold increased risk of lung cancer (Rs4848320: P = 0.005; Rs1110839: P = 0.017). Additionally, there were significantly positive multiplicative interaction of rs4848320 polymorphism with smoking status, with adjusted OR of 2.244 (1.162-4.334), but rs1110839 polymorphism did not exist. CONCLUSIONS: Rs4848320 and rs1110839 polymorphisms may be associated with lung cancer susceptibility. Interaction of rs4848320 risk genotypes with smoking exposure may strengthen the risk effect on lung cancer.

Clinicopathological and prognostic significance of long noncoding RNA MALAT1 in human cancers: a review and meta-analysis.

BACKGROUND: The aberrant regulation of MALAT1 has been indicated to be involved in various carcinogenic pathways contributing to the tumourigenesis and progression of cancers. The current meta-analysis summarized the research advances of MALAT1 functions and analyzed its prognostic value among multiple types of cancers. METHODS: Eligible studies were identified through retrieving the PubMed, Web of Science, and CNKI databases, up to Mar 1, 2018. 28 studies of 5436 patients and 36 studies of 3325 patients were enrolled in the meta-analysis to evaluate the association of MALAT1 expression with survival outcomes and clinical parameters. RESULTS: The results demonstrated that over-expression of MALAT1 may predict lymph node metastasis (pooled OR = 2.335, 95% CI 1.606-3.395, P = 0.000) and distant metastasis (pooled OR = 2.456, 95% CI 1.407-4.286, P = 0.002). Moreover, MALAT1 was also related with tumour size (pooled OR = 1.875, 95% CI 1.257-2.795, P = 0.002) and TNM stage (pooled OR = 2.034, 95% CI 1.111-3.724, P = 0.021). Additionally, elevated MALAT1 expression could predict poor OS (pooled HR = 2.298, 95% CI 1.953-2.704, P = 0.000), DFS (pooled HR = 2.036, 95% CI 1.240-3.342, P = 0.005), RFS (pooled HR = 2.491, 95% CI 1.505-4.123, P = 0.000), DSS (pooled HR = 2.098, 95% CI 1.372-3.211, P = 0.001) and PFS (pooled HR = 1.842, 95% CI 1.138-2.983, P = 0.013) in multivariate model. Importantly, subgroup analyses disclosed that increased MALAT1 expression had a poor OS among different cancer types (Estrogen-dependent cancer: pooled HR = 2.656, 95% CI 1.560-4.523; urological cancer: pooled HR = 1.952, 95% CI 1.189-3.204; glioma: pooled HR = 2.315, 95% CI 1.643-3.263; digestive cancer: pooled HR = 2.451, 95% CI 1.862-3.227). CONCLUSIONS: The present findings demonstrated that MALAT1 may be a novel biomarker for predicting survival outcome, lymph node metastasis and distant metastasis.

Polymorphisms in the H19 gene and the risk of lung Cancer among female never smokers in Shenyang, China.

BACKGROUND: Long non-coding RNA (lncRNA) H19 is a hot spot in tumor development, progression and metastasis. This study assessed the association between H19 genetic polymorphisms and the susceptibility of lung cancer. METHODS: The case-control study was conducted to evaluate the association between four selected single nucleotide polymorphisms (rs217727, rs2107425, rs2735469 and rs17658052) in H19 gene and the risk of lung cancer. There were 556 female never smoking lung cancer patients and 395 cancer-free controls. Unconditional logistic regression analysis was used to analyze the associations between four SNPs and lung cancer risks by calculating the odds ratios and their 95% confidence intervals. The gene-environment interactions were assessed on both additive and multiplicative scales. RESULTS: Compared with carriers carrying homozygous CC genotype, there was a statistically significant increased risk of lung cancer for carriers of the rs2107425 TT genotype (odds ratio = 1.599, 95%CI = 1.106-2.313, P = 0.013). In both dominant and recessive models, significant associations were found between rs2107425 and lung cancer risk, and the corresponding odds ratios were 1.346 (1.022-1.774) and 1.400 (1.011-1.937), with P values 0.035 and 0.043, respectively. There was no significant correlation between lung cancer risk and rs2735469, rs217727 and rs17658052. Interaction analysis showed that their combined effects had a greater impact on lung cancer than individual effects of polymorphism and cooking smoke exposure. However, further analysis showed that the both additive model and the multiplicative model were not statistically significant. CONCLUSION: The polymorphism rs2107425 in H19 gene was associated with the risk of lung cancer among female who never smokes in Shenyang, China.

Long non-coding RNA HOTAIR polymorphism and susceptibility to cancer: an updated meta-analysis.

BACKGROUND: An increasing number of publications are drawing attention to the associations between six common polymorphisms in HOX transcript anti-sense RNA (HOTAIR) and the risk of cancers, while these results have been controversial and inconsistent. We conducted an up-to-date meta-analysis to pool eligible studies and to further explore the possible relationships between HOTAIR polymorphisms (rs920778, rs7958904, rs12826786, 4,759,314, rs874945, and rs1899663) and cancer risk. METHODS: A systematic retrieval was conducted up to 1 July 2017 in the PubMed, Web of Science, and CNKI databases. Eighteen eligible publications including 45 case-control studies with 58,601subjects were enrolled for assessing the associations between the 6 polymorphisms in HOTAIR and cancer risk. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were analyzed to reveal the polymorphisms and susceptibility to cancer. All the statistical analyses were performed using STATA 11.0 software. RESULTS: The pooled analyses detected significant associations between the rs920778 polymorphism and increased susceptibility to cancer in recessive, dominant, allelic, homozygous, and heterozygous models. For the rs7958904 polymorphism, we obtained the polymorphism significantly decreased susceptibility to overall cancer risk among five genetic models rather than recessive and homozygous models. For the rs12826786 polymorphism, we identified it significantly increased susceptibility to cancer risk in all genetic models rather than heterozygous models. However, no significant association was found between the rs1899663, rs874945, and rs4759314 polymorphisms and susceptibility of cancer. CONCLUSION: These findings of the meta-analysis suggest that HOTAIR polymorphism may contribute to cancer susceptibility.

Synthesis of Low-Dimensional Polyion Complex Nanomaterials via Polymerization-Induced Electrostatic Self-Assembly.

Nanostructured polyion complexes (PICs) are appealing in biomaterials applications. Yet, conventional assembly suffers from the weakness in scale-up and reproducibility. Only a few low-dimensional PICs are available to date. Herein we report an efficient and scalable strategy to prepare libraries of low-dimensional PICs. It involves a visible-light-mediated RAFT polymerization of ionic monomer in the presence of a polyion of the opposite charge at 5-50 % w/w total solids concentration in water at 25 °C, namely, polymerization-induced electrostatic self-assembly (PIESA). A Vesicle, multi-compartmental vesicle, and large-area unilamellar nanofilm can be achieved in water. A long nanowire and porous nanofilm can be prepared in methanol/water. An unusual unimolecular polyion complex (uPIC)-sphere-branch/network-film transition is reported. This green chemistry offers a general platform to prepare various low-dimensional PICs with high reproducibility on a commercially viable scale under eco-friendly conditions.

Detection of Multiple Parallel Transmission Outbreak of Streptococcus suis Human Infection by Use of Genome Epidemiology, China, 2005.

Streptococcus suis sequence type 7 emerged and caused 2 of the largest human infection outbreaks in China in 1998 and 2005. To determine the major risk factors and source of the infections, we analyzed whole genomes of 95 outbreak-associated isolates, identified 160 single nucleotide polymorphisms, and classified them into 6 clades. Molecular clock analysis revealed that clade 1 (responsible for the 1998 outbreak) emerged in October 1997. Clades 2-6 (responsible for the 2005 outbreak) emerged separately during February 2002-August 2004. A total of 41 lineages of S. suis emerged by the end of 2004 and rapidly expanded to 68 genome types through single base mutations when the outbreak occurred in June 2005. We identified 32 identical isolates and classified them into 8 groups, which were distributed in a large geographic area with no transmission link. These findings suggest that persons were infected in parallel in respective geographic sites.

Metal-Folded Single-Chain Nanoparticle: Nanoclusters and Self-Assembled Reduction-Responsive Sub-5-nm Discrete Subdomains.

Easy access to discrete nanoclusters in metal-folded single-chain nanoparticles (metal-SCNPs) and independent ultrafine sudomains in the assemblies via coordination-driven self-assembly of hydrophilic copolymer containing 9% imidazole groups is reported herein. 1 H NMR, dynamic light scattering, and NMR diffusion-ordered spectroscopy results demonstrate self-assembly into metal-SCNPs (>70% imidazole-units folded) by neutralization in the presence of Cu(II) in water to pH 4.6. Further neutralization induces self-assembly of metal-SCNPs (pH 4.6-5.0) and shrinkage (pH 5.0-5.6), with concurrent restraining residual imidazole motifs and hydrophilic segment, which organized into constant nanoparticles over pH 5.6-7.5. Atomic force microscopy results evidence discrete 1.2 nm nanoclusters and sub-5-nm subdomains in metal-SCNP and assembled nanoparticle. Reduction of metal center using sodium ascorbate induces structural rearrangement to one order lower than the precursor. Enzyme mimic catalysis required media-tunable discrete ultrafine interiors in metal-SCNPs and assemblies have hence been achieved.

Polymorphisms in miR-135a-2, miR-219-2 and miR-211 as well as their interaction with cooking oil fume exposure on the risk of lung cancer in Chinese nonsmoking females: a case-control study.

BACKGROUND: The associations between microRNAs and lung cancer have received increasing attention. This study assess the association between polymorphisms in miR-135a-2, miR-219-2 and miR-211 genes and the risk of lung cancer, as well as the gene-environment interaction between these polymorphisms and cooking oil fume exposure. METHODS: A case-control study featuring 268 cases and 266 controls was conducted. The associations of miR-135a-2 rs10459194, miR-219-2 rs10988341 and miR-211 rs1514035 polymorphisms with the risk of lung cancer were analyzed. The gene-environment interactions were also reported on both additive and multiplicative scales. RESULTS: There were no statistically significant associations between the single-nucleotide polymorphisms (SNPs) and lung cancer or lung adenocarcinoma. The individuals with both a risk genotype of miRNA SNPs and exposure to a risk factor (cooking oil fumes) were at higher risk of lung cancer than those with only one of these two risk factors (odd ratios of 2.208, 1.285 and 1.813 for miR-135a-2 rs10459194; 2.164, 1.209 and 1.806 for miR-219-2 rs10988341; and 2.122, 1.146 and 1.725 for miR-211 rs1514035, respectively). However, the measures of biological interaction indicate that there was no such interaction between the three SNPs and exposure to cooking oil fumes on an additive scale. Logistic regression models also suggested that the gene-environment interactions were not statistically significant on a multiplicative scale. CONCLUSIONS: There were no significant associations between the polymorphisms in miRNAs (miR-26a-1 rs7372209, miR-605 rs2043556 and miR-16-1 rs1022960) and the risk of lung cancer in the Chinese nonsmoking female population. The interactions between these polymorphisms in miRNAs and cooking oil fume exposure were also not statistically significant.

Decreased miR-198 expression and its prognostic significance in human gastric cancer.

BACKGROUND: MicroRNAs (miRNAs) have been proved to play important roles in the tumorigenesis and development of human gastric cancer (GC). Our study aims to investigate the expression and clinical significance of miR-198 in GC patients. METHODS: Quantitative real-time polymerase chain reaction (RT-PCR) was performed to evaluate miR-198 levels in 106 pairs of GC specimens and adjacent noncancerous tissues. Then, the associations of miR-198 expression with clinicopathological factors and patient's survival were determined. RESULTS: The expression levels of miR-198 in GC tissues were significantly lower than those in corresponding noncancerous tissues (p<0.01). Decreased miR-198 expression was significantly associated with larger tumor size, deeper invasion depth, positive lymph node metastasis, advanced tumor-node-metastasis (TNM) stage, and shorter overall survival. Moreover, multivariate regression analysis identified low miR-198 expression as an independent predictor of poor survival. CONCLUSIONS: These findings suggested that miR-198 downregulation may be associated with progression of GC and that this miR may be an independent prognostic marker for GC patients.

Inflammatory cytokine expression in the quadriceps of rats with posttraumatic knee stiffness: A preliminary study.

The primary purpose of this study was to investigate cytokine expression in the quadriceps of rats with posttraumatic knee stiffness (PTKS) and to determine the effect of exercise training on these cytokines at different follow-up time points. The PTKS rats were randomly assigned into two even groups. The treatment group received exercise training, while the control group received no treatment. Quadriceps specimens were harvested randomly from each group at 8, 12, 16, and 20 weeks. RT-qPCR and immunohistochemical analyses were used to assess the protein and mRNA expression levels of the cytokines IL-1, IL-2, TNF-α, COX-1, and COX-2. TNF-α immunostaining did not differ between the treated and control group tissues, whereas weak immunostaining was observed for all other cytokines in the specimens from the treatment group compared with those from the control group at approximately 12 and 20 weeks. The cytokine levels decreased at approximately 8 weeks in the treatment group, whereas these levels remained elevated or plateaued in the control group. These differences were statistically significant (p<0.05). This study demonstrated that the expression of cytokines IL-1, IL-2, COX-1, and COX-2 increased in the quadriceps of rats with PTKS and that exercise training affected the observed profile trends of these cytokines.

Multilocus sequence typing analysis of Cronobacter spp. isolated from China.

Multilocus sequence typing (MLST) has proven to be an effective approach for the subtyping isolates of the Cronobacter genus and to exhibit a high level of discrimination between isolates. In this study, 151 Cronobacter strains were isolated from different sources and provinces across China from 2010 to 2012 and analyzed by MLST. Their sequence type profiles were compared with strains from other countries which were widely geographically and temporally distributed. Out of 151 strains in this study, the majority of strains were Cronobacter sakazakii (70.9 %), C. malonaticus (15.9 %), C. dublinensis (10.6 %), C. turicensis (2.0 %), and C. muytjensii (0.7 %). The strains were divided into 85 sequence types (STs), among which only 17 had previously been reported in other countries. The 85 identified STs for the Cronobacter genus were grouped into 14 clonal complexes and 47 singletons according to eBURST algorithm. The Cronobacter isolated from China showed a high diversity when they were subtyped using the MLST method. When compared to the Cronobacter PubMLST database, some sequence types of strains cultured from food and/or water in this study were also the same with strains isolated from patients in other countries as reported previously. This result showed the potential hazard of strains contaminating water and weaning food from China.

Homology analysis of pathogenic Yersinia species Yersinia enterocolitica, Yersinia pseudotuberculosis, and Yersinia pestis based on multilocus sequence typing.

We developed a multilocus sequence typing (MLST) scheme and used it to study the population structure and evolutionary relationships of three pathogenic Yersinia species. MLST of these three Yersinia species showed a complex of two clusters, one composed of Yersinia pseudotuberculosis and Yersinia pestis and the other composed of Yersinia enterocolitica. Within the first cluster, the predominant Y. pestis sequence type 90 (ST90) was linked to Y. pseudotuberculosis ST43 by one locus difference, and 81.25% of the ST43 strains were from serotype O:1b, supporting the hypothesis that Y. pestis descended from the O:1b serotype of Y. pseudotuberculosis. We also found that the worldwide-prevalent serotypes O:1a, O:1b, and O:3 were predominated by specific STs. The second cluster consisted of pathogenic and nonpathogenic Y. enterocolitica strains, two of which may not have identical STs. The pathogenic Y. enterocolitica strains formed a relatively conserved group; most strains clustered within ST186 and ST187. Serotypes O:3, O:8, and O:9 were separated into three distinct blocks. Nonpathogenic Y. enterocolitica STs were more heterogeneous, reflecting genetic diversity through evolution. By providing a better and effective MLST procedure for use with the Yersinia community, valuable information and insights into the genetic evolutionary differences of these pathogens were obtained.

Isolation and molecular typing of Cronobacter spp. in commercial powdered infant formula and follow-up formula.

Cronobacter spp. (Enterobacter sakazakii) are important foodborne pathogens. Infections with this pathogen can lead to neonatal meningitis, necrotizing enterocolitis, and bacteremia. This study examined Cronobacter spp. contamination in commercial powdered infant formulas (PIFs) and follow-up formulas (FUFs) in China. Forty-nine of 399 samples were contaminated with Cronobacter spp. and 10.2% of the isolates were resistant to cefotaxime; in contrast, all of the tested isolates were susceptible to amikacin, amoxicillin/clavulanic acid, cefepime, ciprofloxacin, imipenem, and meropenem. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) analyses produced a total of 16 PFGE banding patterns and 11 sequence types (STs), including 7 novel STs. In summary, the rates at which Cronobacter spp. were isolated from commercial PIF and FUF samples in China were relatively high, and the isolated strains exhibited high susceptibility in vitro to most antibiotics. The PFGE method exhibited higher typing capability than the MLST method, and molecular typing results revealed that the contamination of PIF and FUF with Cronobacter spp. in China may be mainly due to the addition of contaminated materials. Thus, the development of more effective control strategies during the manufacturing process is needed.