[Microorganisms in the urethral secretions of chronic prostatitis patients: A genomic analysis].

OBJECTIVE: To investigate the differences in the microbial floras in the urethral secretions of the patients with chronic prostatitis to provide some reliable pathogenic evidence for the diagnosis and treatment of the disease. METHODS: Using high-throughput second-generation sequencing technology, we detected the microorganisms in the urethral secretions from 33 chronic prostatitis patients and 30 normal healthy males. We analyzed the significant differences in the microbial flora between the two groups via the rank-sum test and performed data processing with the bioinformatics software, P < 0.05 considered as with statistically significant difference. RESULTS: Statistically significant differences were observed in 17 kinds of bacteria from the urethral secretions between the normal healthy controls and chronic prostatitis patients. LEfSe analysis showed that the microorganisms with most significant abundance difference in the urethral secretions of the chronic prostatitis patients included micrococcaceae, coriobacteriaceae, coriobacteriales, coriobacteriia, weeksellaceae, comamonadaceae, enterobacteriaceae, enterobacteriales, xanthomonadaceae, and xanthomonadales. Principal component analysis (PCA) revealed significant difference in the microbial composition between the two groups. CONCLUSIONS: There is a certain correlation between chronic prostatitis and changes in the composition of urethral microbial floras. Chronic prostatitis may result from concerted action of multiple microbes rather than a single one.

Screening for chronic prostatitis pathogens using high-throughput next-generation sequencing.

BACKGROUND: The pathogens responsible for chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS; NIH category III) are not currently known. the present study utilized high-throughput next-generation sequencing to screen for potential pathogens associated with NIH category III CP (CP III). METHODS: This study included 33 patients with CP III and 30 healthy men, from which one sample each of urethral secretions and expressed prostatic secretion (EPS) was collected. High-throughput next-generation sequencing was performed to detect the sequence variations and the relative abundance of the bacterial 16S ribosomal variable region and fungal internal transcribed spacer region in all samples. Bioinformatics software and databases were used for data analysis, and differences with P < .05 were considered statistically significant. RESULTS: Unweighted pair group method with arithmetic mean (UPGMA) cluster analysis, principal component analysis (PCA), and Spearman's rank correlation showed that the microbial compositions of the urethral secretions and EPS collected from the same subject were essentially the same. CONCLUSIONS: No potential pathogens were identified in diagnosed patients with CP III. The EPS may be free from bacteria before and after infection. Changes in the urinary tract microbiome may disrupt the microecological balance of the urinary system, thereby leading to CP III. Conversely, the true pathogens of CP III may not be prokaryotic or eukaryotic microorganisms, Future research may involve the evaluation of noncellular microbes.

Parallel Validation of Three Molecular Devices for Simultaneous Detection and Identification of Influenza A and B and Respiratory Syncytial Viruses.

Rapid identification of respiratory pathogens, such as influenza virus A (FluA), influenza virus B (FluB), and respiratory syncytial virus (RSV), reduces unnecessary antimicrobial use and enhances infection control practice. We performed a comparative evaluation of three molecular methods: (i) the Aries Flu A/B & RSV, (ii) the Xpert Xpress Flu/RSV, and (iii) the Cobas Flu A/B & RSV assays. The clinical performances of the three methods were evaluated using 200 remnant nasopharyngeal swab (NPS) specimens against a combined reference standard. The limits of detection (LODs) were determined using FluA, FluB, and RSV control strains with known titers. The 95% LODs were between 1.702 and 0.0003 50% tissue culture infective dose (TCID50), with no significant differences revealed among the three assays. Perfect qualitative detection agreement was obtained in the reproducibility study. The Cobas assay failed at the first run on 13 clinical specimens, resulting in an invalid rate of 6.5%. The sensitivities and specificities for all assays were 96.0 to 100.0% and 99.3 to 100% for all three viruses. For on-demand single-specimen and batched 12-specimen workflows, the test turnaround times were 115.5 and 128.8 min for the Aries assay (12 sample capacity), 34.2 and 44.2 min for the Xpress assay (16 sample capacity), and 21.0 and 254.4 min for the Cobas assay (one instrument), respectively. In summary, the Aries, Xpress, and Cobas Liat assays demonstrated excellent sensitivities and specificities for simultaneous detection and identification of FluA, FluB, and RSV from NPS specimens in cancer patients. Test turnaround time was significantly shorter on the Xpress when instrument scalability is unlimited.

Influence of environmental and genotypic factors on biofilm formation by clinical isolates of group B streptococci.

Group B Streptococcus (GBS) colonizes the gastrointestinal and urogenital tracts of approximately 30% of women, and it can cause sepsis and meningitis in neonates. GBS has been shown to form biofilms in vitro, but the effects of environmental and genotypic factors upon GBS biofilm formation are unclear. The aim of the present study was to optimize culture conditions for enhanced GBS biofilm production. Furthermore, this study also investigated the influences of strain lineage, pilus profile, and isolation source on GBS biofilm formation. The results demonstrate that the fed-batch mode and acidic pH strongly enhanced GBS biofilm formation in vitro. These findings suggest that the fed-batch mode may be suitable for both screening and fundamental studies of GBS biofilm formation. Moreover, this study demonstrated a correlation between the hyper virulent clonal complex 17 and a strong biofilm phenotype.

Fecal calprotectin concentrations in cancer patients with Clostridium difficile infection.

Fecal calprotectin (fCPT) has been used as a surrogate marker for assessment of intestinal inflammation. We explore the utility of fCPT values as a diagnostic aid in cancer patients with suspected Clostridium difficile infection (CDI). A total of 232 stool specimens submitted for GeneXpert C. difficile PCR testing were included in the study. All specimens were tested for fCPT and toxin/GDH antigens. Clinical severity of CDI cases was determined by the IDSA/SHEA criteria. Significant differences of median fCPT values between CDI (n = 117, Median 183.6 µg/g) and non-CDI (n = 115, 145.6 µg/g, p = 0.006) patients were seen. In CDI patents, significantly lower fCPT values were found in patients with mild to moderate (n = 95, 182.1 µg/g) than those with severe and severe to complicated (n = 22, 218.5 µg/g, p = 0.014) scores, and among those that were toxin positive (n = 24, 200.2 µg/g) vs. toxin negative (n = 86, 182.8 µg/g, p = 0.044). Despite this overall trend, wide variations in fCPT values were found in all categories examined. A logistic regression analysis revealed that the fCPT values correlated independently with the severity of clinical manifestations (OR = 2.021, 95%CI = 1.132-3.608); however, it did not correlate with other clinical outcomes. Our study findings show that high fecal calprotectin levels correlate with toxin-positive and clinically severe CDI; however, wide variations in individual measurements preclude establishment of reliable cut-offs for routine diagnostic use in cancer patients.

[Value of endobronchial ultrasound elastography in the diagnosis of mediastinal and hilar lymph node metastasis in lung cancer].

OBJECTIVE: To assess the value of endobronchial ultrasound elastography in the diagnosis of mediastinal and hilar lymph node metastasis in lung cancer. 
 METHODS: A total of 40 patients with lung cancer underwent ultrasonic bronchoscope examination before operation. Elastography and standard endobronchial ultrasound (EBUS) of lymph nodes were performed before EBUS-guided transbronchial needle aspiration (EBUS-TBNA). The elastography characteristics was compared between benign and malignant lymph nodes. The diagnosis accuracy in malignant lymph nodes was also compared between the elastography and the standard EBUS. The value of the elastography was assessed in distinguishing the benign and malignant lymph nodes.
 RESULTS: 1) The significant indicators of standard EBUS in diagnosis of malignant lymph nodes were hypoechonic nodes, uneven echo, distinct boundary and short diameter greater than 1 cm (all P<0.01). 2) There was significant difference in the elastosonography grading score between benign and malignant lymph nodes (P<0.01). 3) The elastography grading score was more sensitive and specific in determining the malignant lymph node than the standard EBUS criteria. The area under the receiver operating characteristic curve (AUC) was maximal when the elastography grading score was ≥2.5. The specificity, sensitivity, positive predictive value, negative predictive value of elastography grading score was 76.9%, 85.7%, 85.7% and 76.9% in distinguishing malignant and benign nodes. The overall accuracy of elastography grading score was 82.3%. The combination of elastography grading score, low echo, distinct boundary and short diameter greater than 1 cm showed the best diagnostic efficiency value. The AUC was 0.911. In distinguishing malignant and benign nodes, the specificity, sensitivity, positive predictive value, negative predictive value and accuracy of the combined indexes was 84.6%, 88.1%, 90.2%, and 81.5% respectively. The overall accuracy was 86.8%.
 CONCLUSION: The endobronchial ultrasound elastography can effectively distinguish the mediastinal and hilar lymph node metastasis in lung cancer. The diagnosis accuracy of elastography in malignant lymph node is higher than that of standard EBUS criteria. The combination of elastosonography grading score and standard EBUS criteria can improve the diagnostic efficiency.

Fusobacterium nucleatum subspecies identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

We explored the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for identification of Fusobacterium nucleatum subspecies. MALDI-TOF MS spectra of five F. nucleatum subspecies (animalis, fusiforme, nucleatum, polymorphum, and vincentii) were analyzed and divided into four distinct clusters, including subsp. animalis, nucleatum, polymorphum, and fusiforme/vincentii. MALDI-TOF MS with the modified SARAMIS database further correctly identified 28 of 34 F. nucleatum clinical isolates to the subspecies level.

Clinical validation of the Lyra direct HSV 1+2/VZV assay for simultaneous detection and differentiation of three herpesviruses in cutaneous and mucocutaneous lesions.

We evaluated the Lyra Direct HSV 1+2/VZV multiplex real-time PCR assay for the detection and differentiation of herpes simplex virus 1 (HSV-1), HSV-2, and varicella-zoster virus (VZV) on 695 consecutive cutaneous and mucocutaneous lesion specimens. The intra-assay and interassay coefficient of variation values for the Lyra assay were 0.29 to 1.30% and 2.33 to 2.61%, respectively. The sensitivities, specificities, and positive and negative predictive values were 93.4 to 95.0%, 96.1 to 96.8%, 78.0 to 80.3%, and 99.0 to 99.1%, respectively, in comparison to those of viral culture. The values were further improved when a resolution analysis was performed with a laboratory-developed PCR assay.

Evaluation of Alere i Influenza A&B for rapid detection of influenza viruses A and B.

Rapid and accurate diagnosis of influenza is important for infection control, as well as for patient management. Alere i Influenza A&B is an isothermal nucleic acid amplification-based integrated system for detection and differentiation of influenza virus A and influenza virus B. The performance of the Alere i Influenza A&B was screened using frozen nasopharyngeal-swab specimens collected in viral transport medium (VTM) that were originally tested fresh with the FilmArray Respiratory Panel (RP) assay during the 2012-2013 influenza outbreak. In total, 360 VTM specimens were selected for Alere i Influenza A&B testing: 40 influenza virus A H1N1-2009 (influenza virus A-1), 40 influenza virus A H3N2 (influenza virus A-3), 37 influenza virus A "equivocal" or "no subtype detected" (influenza virus A-u), 41 influenza virus B, and 202 influenza virus-negative specimens, as initially determined by the FilmArray RP assay. The Alere assay showed sensitivities of 87.2%, 92.5%, 25.0%, and 97.4% for influenza virus A-1, influenza virus A-3, influenza virus A-u, and influenza virus B, respectively, after discordant resolution by Prodesse ProFLU+ PCR. The specificities were 100% for both influenza virus A and influenza virus B. In general, the Alere i Influenza A&B provided good sensitivity, although the assay did show poorer sensitivity with samples determined to have low influenza virus A titers by Prodesse ProFlu+ PCR (a mean real-time PCR threshold cycle [CT] value of 31.9 ± 2.0), which included the majority of the samples called influenza virus A "equivocal" or "no subtype detected" by a single BioFire FilmArray RP test. The integrated, rapid, and simple characteristics of the Alere i Influenza A&B assay make it a potential candidate for point-of-care testing, with a test turnaround time of less than 15 min.

Respiratory virus infections among children in South China.

Acute respiratory tract infection is an important cause of morbidity and mortality with a worldwide disease burden. This study aimed to determine the prevalence and clinical characteristics of children with viral-induced acute respiratory tract infection, in Southern China. Nasopharyngeal aspirate samples from 1,980 pediatric patients with suspected acute respiratory tract infection, and 82 samples from healthy subject controls were collected for routine examination at the Second Affiliated Hospital of Shantou University Medical College, from October 2007 to August 2011. Specimens were tested by multiplex polymerase chain reaction (mPCR). At least one or more viruses were detected from 1,087 samples (54.9%). These included laboratory confirmations for 446 respiratory syncytial virus (RSV), 386 influenza virus A (FluA), 315 human rhinovirus (HRV), 135 human bocavirus (HBoV), 119 Parainfluenza virus 3 (PIV3), 82 Parainfluenza virus 1 (PIV1), 66 adenovirus (ADV), 53 WU polyomavirus (WUPyV), 52 human metapneumovirus (hMPV), and 29 influenza virus B (FluB) samples. Samples from healthy subjects were negative for any virus. Of the patients with positive specimens, 107 (9.8%) were admitted to pediatric intensive care unit (PICU). Co-infection with at least two of the viral pathogens under study was observed in 325 of the 1,980 patients (16.4% of the total number of cases). These findings may help in the diagnosis of viral infections of the respiratory tract in children, and help to consider current and potential therapeutic approaches for the treatment of acute respiratory tract infection, and further respiratory complications.

Oncogenic HPV infection resembling pseudocondyloma of vulvae: a descriptive study of 31 cases.

OBJECTIVE: Report a special type of human papillomavirus infection resembling pseudocondyloma of vulvae. The characteristics of the clinical manifestation and subtypes of the HPV infection were studied. METHODS: Thirty-one women with unprotected sex and genital warts resembling pseudocondyloma of vulvae were involved in this study. The clinical and histological manifestations were characterized. The genotypes of human papillomavirus were determined by a reverse hybridization of polymerase chain reaction (PCR) RESULTS: Thirteen HPV genotypes were detected from 31 cases. Of 13 genotypes, 3 were non-oncogenic and 10 were oncogenic. At least, one of oncogenic genotypes was detected from each patient. Among 31 cases, 10 were found with one genotype of the HPV infection, 14 with 2 genotypes of HPV and 7 with at least 3 genotypes. The most common genotype was genotype 16 that was detected from 15 of 31 samples (48%). CONCLUSION: There is a special type of oncogenic HPV infection clinically resembling pseudocondyloma of vulvae. Some of the patients who were infected with this type of HPV infection may have been misdiagnosed as pseudocondyloma of vulvae in the past time.

WU polyomavirus infection among children in South China.

This study aimed at investigating the prevalence and clinical characteristics of children with respiratory infection by WU polyomavirus (WUPyV) in Southern China. Nasopharyngeal aspirate samples were collected from 771 children with acute respiratory tract infection admitted to hospital and 82 samples from healthy subjects for routine examination at the outpatient service at the Second Affiliated Hospital of Shantou University, Medical College from July 2008 to June 2009. WUPyV was detected by the polymerase chain reaction (PCR) and DNA sequencing. All WUPyV-positive specimens were characterized further for nine viruses causing common respiratory infections, including influenza A and B, respiratory syncytial virus (RSV), parainfluenza virus (PIV) 1 and 3, human metapneumovirus, human bocavirus, adenovirus, and rhinovirus by PCR or real time (RT)-PCR. Fifteen out of 771 specimens from patients with acute respiratory tract infection, but none from healthy subjects, were positive for WUPyV and the positivity rate was 2%. Patients with WUPyV infection were between 2 and 48 months of age, and nine of the patients were male while six female. Four out of 15 patients were co-infected with RSV, one with adenovirus or rhinovirus, respectively. Patients with WUPyV infection displayed predominantly cough, moderate fever, and wheezing, and were diagnosed with pneumonia (n = 8), bronchiolitis (n = 4), upper respiratory tract infections (n = 2) and bronchitis (n = 1). One patient developed encephalitis. Therefore, WUPyV infection can cause acute respiratory tract infection with atypical symptoms, including severe complications, in children.

Mass spectrometry biotyper system identifies enteric bacterial pathogens directly from colonies grown on selective stool culture media.

We evaluated the performance and cost-effectiveness of a matrix-assisted laser desorption ionization time-of-flight mass spectrometry-based Biotyper system for the routine identification of common enteric bacterial pathogens seen in middle Tennessee from suspicious colonies grown on selective stool culture media. A total of 304 suspicious colonies were selected and further identified from 605 stool specimens. The suspicious colonies were analyzed by the Biotyper system, and the results were compared to those from routine phenotypic methods, which identified 22 Salmonella species, 39 Shigella species, 3 enterohemorrhagic Escherichia coli (EHEC) isolates, 2 Yersinia enterocolitica isolates, 2 Campylobacter species, and 236 gastrointestinal normal flora isolates. The Biotyper system correctly identified the Salmonella species, Yersinia enterocolitica, and Campylobacter species but failed to distinguish the Shigella species and EHEC isolates from E. coli. Among the 236 normal flora isolates, 233 (98.7%) and 228 (96.6%) agreed at the genus and species levels, respectively, between the phenotypic and Biotyper methods. Organism identification scores were insignificantly different between colonies directly from selective media and subsequently from pure subculture. The entire Biotyper identification procedure, from smear preparation to final result reporting, can be completed within 30 min. The Biotyper system provides a rapid and simple screening tool for identifying many, but not all, suspicious colonies grown on selective media within 24 h after inoculation, which shortens test turnaround time by 2 to 3 days.

[Clinical Significance of Gene Mutation Detection for Female Heterozygotes with Glucose-6-Phosphate Dehydrogenase Deficiency].

OBJECTIVE: To explore the clinical significance of G6PD gene mutation detection in female heterozygote with G6PD deficiency. METHODS: G6PD activity and fourteen common G6PD gene mutations in female blood samples were detected by biochemical phenotype detection and PCR-reverse dot blotting, respectively. Unidentified genotype of G6PD positive samples was further ascertained by direct DNA sequencing. The results from two methods were compared and analyzed. RESULTS: A total of 493 unrelated females were enrolled, and the G6PD activity and G6PD mutations was detected. Among them, 473 females were found to be normal in G6PD activity and 20 females with G6PD deficiency, and the detection rate by G6PD activity method was 4.06%. In all enrolled females, G6PD gene mutations, including the mutation of c.1311 C＞T, were identified in 130 females, and the detection rate was 26.3%. Detection rate of the mutations that can lead to G6PD deficiency was 8.11%. The detection rates between the two methods were significantly different (P＜0.01). The misdiagnosis rate of the G6PD activity detection reached 49. 94% for the female heterozygotes. Eight G6PD mutations and 13 mutation patterns were identified in the research, and most of mutation patterns were single nucleotide missense mutation. In addition to c.1311C＞T mutation, the most common mutations were c.1376G＞T, c.1388G＞A and c.95 A＞G. G6PD mutations were identified in 19 of 20 females with G6PD deficiency, and were also detected in 21 of 473 females with normal G6PD activity, of which the rate of heterozygous mutation was 90.88%. CONCLUSION: The phenotype detection based on G6PD enzyme activity alone is not sufficient for the diagnosis of female heterozygotes. The detection of G6PD mutations that covers the common mutations in specified region can effectively identify the female heterozygotes with normal G6PD activity.

Hierarchical porous and hydrophilic metal-organic frameworks with enhanced enzyme activity.

Metal-organic frameworks (MOFs) for enzyme encapsulation-induced biomimetic mineralization under mild reaction conditions are commonly microporous and hydrophobic, which result in a rather high mass transfer resistance of the reactants and restrain the enzyme catalytic activity. Herein, we prepared a type of hierarchical porous and hydrophilic MOF through the biomimetic mineralization of enzymes, zinc ions, 2-methylimidazole, and lithocholic acid. The hierarchical porous structure accelerated the diffusion process of the reactants and the increased hydrophilicity conferred interfacial activity and increased the enzyme catalytic activity. The immobilized enzyme retained higher catalytic activity than the free enzyme and exhibited enhanced resistance to alkaline, organic, and high-temperature conditions. The nanobiocatalyst was reusable and showed long-term storage stability.

Sustainable separation of bio-based cadaverine based on carbon dioxide capture by forming carbamate.

Bio-based cadaverine, manufactured by the decarboxylation of l-lysine, is an important raw material. However, the extractive-distillation separation and purification of cadaverine from bioconversion fluids require high energy consumption and leads to the loss of self-released carbon dioxide during the decarboxylation of l-lysine. This study focuses on the green and sustainable separation of bio-based cadaverine based on the capture of self-released carbon dioxide by cadaverine forming carbamate. Results showed that granular-activated carbon JK1 shows the best decolorization efficiency and achieves a higher cadaverine yield. After three times of solventing-out crystallization, refined cadaverine carbamate with 99.1% purity and total 57.48% yield was obtained. It was also found that the refined cadaverine carbamate consists of mixed crystals having numerous structural forms that can easily dissociate carbon dioxide. Furthermore, the amine carbamate strategy may be of great value for the development of a green and sustainable separation mode of bio-based amines and carbon dioxide capture.

A novel point-of-care test of respiratory syncytial viral RNA based on cellulose-based purification and convective PCR.

BACKGROUND: Respiratory syncytial virus (RSV) infection is a global public-health problem. Timely diagnostics are needed for high-risk patients. Several methods have been used for RSV detection but not suitable for on-site detection due to the requirement of specialized laboratories and expensive equipment. METHODS: We developed a convenient, rapid and low-cost method of nucleic acids (NA) extraction based on cellulose paper, which could extract NA from nasopharyngeal swabs (NPSs) within 1 min. This extraction method was integrated with fluorescence convection polymerase chain reaction (CPCR), which easily affordable and easy-to-use NA detection of the RSV in 33 min. RESULTS: The developed cellulose-based NA purification combine with CPCR (CP-CPCR) reliably detected as little as 0.01 TCID50/mL of RSV cultures. CP-CPCR performance was tested further using NPSs: it showed sensitivity of 100% and a specificity of 100% compared with traditional extraction and amplification methods. CONCLUSIONS: Our evaluation confirmed high specificity, sensitivity and efficient of the CP-CPCR, which can be used widely for RSV testing in resource-limited settings.

[Viral pathogens of acute lower respiratory tract infection in hospitalized children from East Guangdong of China].

OBJECTIVE: To investigate the viral pathogens of acute lower respiratory tract infection (ALRTI) in hospitalized children from East Guangdong Province of China and the relationship of the pathogens with age and seasons. METHODS: The nasopharyngeal aspirates samples obtained from 345 hospitalized children with ALRTI were investigated for respiratory syncytial virus (RSV), human bocavirus (HBoV), human metapneumovirus (hMPV), influenza virus types A and B, rhinovirus, parainfluenza virus types 1 and 3 and adenovirus by PCR. RESULTS: Viral pathogens were detected in 178 patients (51.6%). RSV was the most frequent (19.3%). Novel viruses hMPV (3.2%) and HBoV (3.2%) were found. A highest detection rate (61.9%) of virus was found between January to March. The infants aged 1 to 6 months showed a higher detection rate (71.3%) of virus than the other age groups. The detection rate of viral pathogens was 72.6% in children with bronchiolitis, followed by asthmatic bronchitis (70.0%) and bronchial pneumonia (44.6%). CONCLUSIONS: RSV remained the leading viral pathogens in children with ALRTI in East Guangdong of China. Novel viruses HBoV and hMPV were also important pathogens. The detection rate of viral pathogens was associated with seasonal changes and age. Different respiratory infectious diseases had different viral detection rates, with highest detection rate in bronchiolitis cases.

Reliable and reusable whole polypropylene plastic microfluidic devices for a rapid, low-cost antimicrobial susceptibility test.

Using an antimicrobial susceptibility test (AST) as an example, this work demonstrates a practical method to fabricate microfluidic chips entirely from polypropylene (PP) and the benefits for potential commercial use. Primarily caused by the misuse and abuse of antibiotics, antimicrobial resistance (AMR) is a major threat to modern medicine. The AST is a promising technique to help with the optimal use of antibiotics for reducing AMR. However, current phenotypic ASTs suffer from long turnaround time, while genotypic ASTs suffer from low reliability, and both are unaffordable for routine use. New microfluidics based AST methods are rapid but still unreliable as well as costly due to the PDMS chip material. Herein, we demonstrate a convenient method to fabricate whole PP microfluidic chips with high resolution and fidelity. Unlike PDMS chips, the whole PP chips showed better reliability due to their inertness; they are solvent-compatible and can be conveniently reused and recycled, which largely decreases the cost, and are environmentally friendly. We specially designed 3D chambers that allow for quick cell loading without valving/liquid exchange; this new hydrodynamic design satisfies the shear stress requirement for on-chip bacterial culture, which, compared to reported designs for similar purposes, allows for a simpler, more rapid, and high-throughput operation. Our system allows for reliable tracking of individual cells and acquisition of AST results within 1-3 hours, which is among the group of fastest phenotypic methods. The PP chips are more reliable and affordable than PDMS chips, providing a practical solution to improve current culture-based AST and benefiting the fight against AMR through helping doctors prescribe effective, narrow-spectrum antibiotics; they will also be broadly useful for other applications wherein a reliable, solvent-resistant, anti-fouling, and affordable microfluidic chip is needed.

Characterization of group B Streptococcus isolated from sterile and non-sterile specimens in China.

Group B streptococcus (GBS) is a leading cause of invasive neonatal infections and has increasingly been associated with invasive diseases in non-pregnant adults. We collected 113 GBS isolates recovered from sterile and non-sterile specimens from seven tertiary hospitals in China between October 2014 and September 2016. Medical records were retrospectively reviewed and the sequence types, serotypes, virulence, and antimicrobial resistance profiles of the isolates were characterized and correlated. Significantly higher C-reactive protein and procalcitonin levels and absolute neutrophil counts were observed in patients with invasive infections than in those with non-invasive infections (P < 0.05). The 113 isolates were grouped into 24 sequence types, 5 clonal complexes, and 6 serotypes. multivariate analysis revealed that clonal complex 17 isolates characterized by serotype iii, the surface protein gene rib, and the pilus island pi-2b were independently correlated with invasive infection (or: 6.79; 95% ci: 2.31-19.94, P < 0.001). These results suggest alternative molecular biomarkers for diagnosis and prognosis of GBS infections.