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AHEAD OF PRINT

Volume 71 (2022): Issue 2 (June 2022)

Volume 71 (2022): Issue 1 (March 2022)

Volume 70 (2021): Issue 4 (December 2021)

Volume 70 (2021): Issue 3 (September 2021)

Volume 70 (2021): Issue 2 (June 2021)

Volume 70 (2021): Issue 1 (March 2021)

Volume 69 (2020): Issue 4 (December 2020)

Volume 69 (2020): Issue 3 (September 2020)

Volume 69 (2020): Issue 2 (June 2020)

Volume 69 (2020): Issue 1 (March 2020)

Volume 68 (2019): Issue 4 (January 2019)

Volume 68 (2019): Issue 3 (September 2019)

Volume 68 (2019): Issue 2 (June 2019)

Volume 68 (2019): Issue 1 (March 2019)

Volume 67 (2018): Issue 4 (December 2018)

Volume 67 (2018): Issue 3 (September 2018)

Volume 67 (2018): Issue 2 (June 2018)

Volume 67 (2018): Issue 1 (January 2018)

Volume 66 (2017): Issue 4 (December 2017)

Volume 66 (2017): Issue 3 (September 2017)

Volume 66 (2017): Issue 2 (June 2017)

Volume 66 (2017): Issue 1 (March 2017)

Volume 65 (2016): Issue 4 (December 2016)

Volume 65 (2016): Issue 3 (August 2016)

Volume 65 (2016): Issue 2 (June 2016)

Volume 65 (2016): Issue 1 (March 2016)

Journal Details
Format
Journal
eISSN
2544-4646
First Published
04 Mar 1952
Publication timeframe
4 times per year
Languages
English

Search

Volume 70 (2021): Issue 4 (December 2021)

Journal Details
Format
Journal
eISSN
2544-4646
First Published
04 Mar 1952
Publication timeframe
4 times per year
Languages
English

Search

10 Articles

mini-review

access type Open Access

Silent Genes: Antimicrobial Resistance and Antibiotic Production

Published Online: 16 Oct 2021
Page range: 421 - 429

Abstract

Abstract

Silent genes are DNA sequences that are generally not expressed or expressed at a very low level. These genes become active as a result of mutation, recombination, or insertion. Silent genes can also be activated in laboratory conditions using pleiotropic, targeted genome-wide, or biosynthetic gene cluster approaches. Like every other gene, silent genes can spread through horizontal gene transfer. Most studies have focused on strains with phenotypic resistance, which is the most common subject. However, to fully understand the mechanism behind the spreading of antibiotic resistance, it is reasonable to study the whole resistome, including silent genes.

Keywords

  • silent genes
  • antimicrobial resistance
  • spp.
  • mutations
access type Open Access

Can Lactobacillus spp. Be a Factor Reducing the Risk of Miscarriage?

Published Online: 06 Dec 2021
Page range: 431 - 446

Abstract

Abstract

Pregnancy loss is a common obstetric problem. Significant causes of miscarriage include genetic and epigenetic disorders of the embryo, immunological and endocrine factors, uterine malformations, improper embryo selection, and lifestyle. Perhaps a hitherto underappreciated cause of miscarriage may be an abnormal microbiota composition of the female reproductive system. Lactobacillus spp. is the most common bacteria within the reproductive tract. However, the protective role of Lactobacilli in the vagina has been well described in the literature, while it is still unknown what function Lactobacilli may have in the uterus. Moreover, new research shows that Lactobacillus spp. can have a role in miscarriage. However, both molecular and immunological mechanisms of host-Lactobacillus spp. interactions are not fully understood. Understanding these relationships will help address the importance and extent of the protective role of Lactobacillus spp. in miscarriage.

Keywords

  • miscarriage
  • pregnancy
  • uterine microbiota
  • vaginal microbiota

original-paper

access type Open Access

Chemical Components of Aqueous Extracts of Melia azedarach Fruits and Their Effects on The Transcriptome of Staphylococcus aureus

Published Online: 29 Oct 2021
Page range: 447 - 459

Abstract

Abstract

Staphylococcus aureus is the causative agent of numerous and varied clinical infections. Crude aqueous extracts of Melia azedarach fruits inhibit the planktonic growth and initial biofilm formation of S. aureus in a dose-dependent manner. Moreover, the biofilm topologies became sparse and decreased as the concentration of the aqueous extracts increased. RNA-Seq analyses revealed 532 differentially expressed genes (DEGs) after S. aureus exposure to 0.25 g/ml extracts; 319 of them were upregulated, and 213 were downregulated. The majority of DEGs were categorized into abundant sub-groups in the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Finally, untargeted UHPLC-MS/MS analyses of the aqueous extracts of M. azedarach fruits demonstrated a highly complex profile in positive and negative electrospray ionization modes. The extracts primarily consisted of lipids and lipid-like molecules, organic acids and their derivatives, phenylpropanoids, polyketides, organoheterocyclic compounds, and benzenoids annotated by abundant lipid maps and KEGG pathways. Overall, this study provides evidences that the aqueous extracts of M. azedarach fruits can control S. aureus infections and sought to understand the mode of action of these extracts on S. aureus.

Keywords

  • fruits
  • differentially expressed genes
  • biofilms
  • UHPLC-MS/MS
access type Open Access

QuantiFERON-TB Gold Plus Test in Diagnostics of Latent Tuberculosis Infection in Children Aged 1–14 in a Country with a Low Tuberculosis Incidence

Published Online: 06 Dec 2021
Page range: 461 - 468

Abstract

Abstract

The aim of the study was to evaluate the QuantiFERON-TB Gold Plus (QFT-Plus) test usability in the identification of latent tuberculosis infection (LTBI) in children and the determination of features associated with tuberculin skin test (TST) and QFT-Plus-positive results concerning LTBI. Two-hundred thirteen children aged 1–14 were screened for LTBI due to household contact with TB, suspected TB, or were qualified for biological therapy. The objective of this study was to evaluate the QFT-Plus affectivity as a diagnostic test in the absence of a gold standard (GS) test for the diagnosis of LTBI. The children were diagnosed with QFT-Plus, TST, and culture of TB. The QFT-Plus results were analyzed depending on the children’s age, TST size, and type. In children aged 1–4, the positive predictive value of QFT-Plus was 1, the negative predictive value was 0.94, QFT-Plus sensitivity was 75%, and specificity was 100%. It was observed that in children aged 5–14 years, the level of agreement decreased to the substantial, i.e., 87.2%. Moreover, the negative predictive value was 0.83. QFT-Plus sensitivity was 64%, and specificity was 100%. Statistical analysis of QFT-Plus and TST results showed substantial and almost perfect agreements. Our study suggests that QFT-Plus is helpful in a pediatric practice showing good sensitivity and specificity for LTBI. The BCG vaccine, infections, and concomitant morbidities do not affect QFT-Plus results.

Keywords

  • QuantiFERON-TB Gold Plus
  • tuberculin skin test
  • latent tuberculosis infection
  • tuberculosis
  • children
access type Open Access

Histopathological Analysis of Acinetobacter baumannii Lung Infection in a Mouse Model

Published Online: 20 Dec 2021
Page range: 469 - 477

Abstract

Abstract

Acinetobacter baumannii is the main causative pathogen of nosocomial infections that causes severe infections in the lungs. In this study, we analyzed the histopathological characteristics of lung infection with two strains of A. baumannii (ATCC 19606 and the clinical isolate TK1090) and Pseudomonas aeruginosa PAO-1 in C3H/HeN mice to evaluate the virulence of A. baumannii. Survival was evaluated over 14 days. At 1, 2, 5, or 14 days postinfection, mice of C3H/HeN were sacrificed, and histopathological analysis of lung specimens was also performed. Histopathological changes and accumulation of neutrophils and macrophages in the lungs after infection with A. baumannii and P. aeruginosa were analyzed. Following intratracheal inoculation, the lethality of ATCC 19606- and TK1090-infected mice was lower than that of PAO-1-infected mice. However, when mice were inoculated with a sub-lethal dose of A. baumannii, the lung bacterial burden remained in the mice until 14 days post-infection. Additionally, histopathological analysis revealed that macrophages infiltrated the lung foci of ATCC 19606-, TK1090-, and PAO-1-infected mice. Although neutrophils infiltrated the lung foci of ATCC 19606- and TK1090-infected mice, they poorly infiltrated the lung foci of PAO-1-infected mice. Accumulation of these cells in the lung foci of ATCC 19606- and TK1090-infected mice, but not PAO-1-infected mice, was observed for 14 days post-infection. These results suggest that A. baumannii is not completely eliminated despite the infiltration of immune cells in the lungs and that inflammation lasts for prolonged periods in the lungs. Further studies are required to understand the mechanism of A. baumannii infection, and novel drugs and vaccines should be developed to prevent A. baumannii infection.

Keywords

  • neutrophils
  • macrophages
  • a mouse lung infection model
access type Open Access

A Novel LysR Family Factor STM0859 is Associated with The Responses of Salmonella Typhimurium to Environmental Stress and Biofilm Formation

Published Online: 20 Dec 2021
Page range: 479 - 487

Abstract

Abstract

Salmonella enterica subsp. enterica serovar Typhimurium (ST) is an intracellularly parasitic bacterium. This zoonotic pathogen causes food poisoning and thus imposes a severe threat to food safety. Here, to understand the regulatory roles of the novel transcription factor STM0859 on the response of ST to environmental stress and biofilm formation, the STM0859 gene-deficient strain and the complementation strain ΔSTM0859/STM0859 were generated, respectively. Then, its capacity of responding to environmental stresses and biofilm (BF) formation ability under different stresses, including acid, alkali, high salt, cholate, and oxidative stresses was tested. We further analyzed the interaction between the STM0859 protein and the promoter of the acid stress response-related gene rcsB by performing an electrophoresis mobility shift assay (EMSA). The results showed that acid resistance and BF formation capacities of ST-ΔSTM0859 strain were significantly weaker, as compared with those of Salmonella Typhimurium SL1344 (ST-SL1344) wild strain (p < 0.01). Quantitative qRT-PCR analysis showed that the expression levels of acid stress and BF formation-related genes, rcsB and rpoS, of ST-ΔSTM0859 strain were significantly reduced at the transcription levels, while the transcription levels of these genes were fully restored in complementation strain ST-ΔSTM0859/STM0859. The results of EMSA showed that STM0859 was capable of binding the promoter DNA fragments of the rcsB gene, suggesting that STM0859 can promote the transcription of the rcsB gene through interaction with its promoter, thereby exerting an indirectly regulatory role on the adaptive responses to acid stress and BF formation of ST. This study provided new insights into the regulatory mechanisms of the LysR family factors on the tolerances of ST under adverse environmental stresses.

Keywords

  • Typhimurium
  • biofilm
  • environmental stress
  • gene
access type Open Access

Characteristics of the Cervicovaginal Microenvironment in Childbearing-Age Women with Different Degrees of Cervical Lesions and HR-HPV Positivity

Published Online: 20 Dec 2021
Page range: 489 - 500

Abstract

Abstract

Persistent infection with high-risk human papillomavirus (HR-HPV) is the most important determinate in the development of cervical cancer, and cervical microecology can modulate cervical viral infection. However, few studies have been conducted on the microecological analysis of cervical diseases using strict physiological factors. This study investigated the characteristics and dynamics of cervical microecology in childbearing-age Chinese women with different degrees of HR-HPV-positive cervical lesions. A total of 168 subjects were selected according to the selection criteria, including healthy HPV-negative individuals (n = 29), HR-HPV-infected individuals (n = 29), low-grade squamous intraepithelial lesion individuals (LSIL, n = 32), high-grade squamous intraepithelial lesion individuals (HSIL, n = 40), and cervical cancer individuals (n = 38). We sampled cervical secretions from each subject and performed comparative analysis using the 16S rRNA sequencing method. Comparison analysis showed that Lactobacillus and Ignatzschineria were the dominant genera in the healthy group, while Gardnerella and Prevotella were more enriched in the disease groups. Based on the taxa composition, we roughly divided the development of cervical cancer into two phases: phase I was from healthy status to HR-HPV infection and LSIL; phase II was from LSIL to HSIL and cervical cancer. Different interactions among different genera were observed in different groups. Prevotella inhibited the abundance of Lactobacillus in the healthy group, while Prevotella inhabited the abundance of Gardnerella in the other groups. In the HR-HPV infection group, Ignatzschineria and Enterococcus showed a positive interaction but dissociated with the increase in cervical lesions, which might eventually lead to a continuous decrease in the abundances of Lactobacillus and Ignatzschineria.

Keywords

  • cervical microorganisms
  • cervical lesions
  • 16S rRNA sequencing
access type Open Access

Identification of Genetic Variants of Human Papillomavirus in a Group of Mexican HIV/AIDS Patients and Their Possible Association with Cervical Cancer

Published Online: 20 Dec 2021
Page range: 501 - 509

Abstract

Abstract

Infections caused by the human immunodeficiency virus (HIV) and human papillomavirus (HPV) cause thousands of deaths worldwide each year. So far, there has been no consensus on whether there is a direct relationship between the incidence of neoplasms and the immunosuppression caused by HIV that could help understand if coinfection increases the likelihood of cervical cancer. The objective of the study was to identify the presence of genetic variants of HPV in a group of HIV-positive women and their possible association with cervical cancer. Cervical samples were taken from HIV-positive patients for cytological analysis to identify the HPV genotype by polymerase chain reaction (PCR) and sequencing. The most prevalent L1 capsid protein mutations in the HPV genotype were analyzed in silico. Various types of HPV were identified, both high-risk (HR) and low-risk (LR). The most prevalent genotype was HPV51. Analysis of the L1 gene sequences of HPV51 isolates showed nucleotide variations. Of the samples analyzed in Puebla, Mexico, HPV51 had the highest incidence (17.5%, 7/40). Different mutations, which could be used as population markers, were detected in this area, and they have not been reported in the L1 databases for HPV51 in Mexico. Genotypes 6, 14, 86, 87, 89, and 91, not detected or reported in samples from patients with HPV in Mexico, were also identified. Data from the population analyzed suggest no direct relationship between HIV immunosuppression and cervical cancer, regardless of the high- or low-risk HPV genotype. Furthermore, it is possible to develop regional population markers for the detection of HPV based on the mutations that occur in the sequence of nucleotides analyzed.

Keywords

  • cervical cancer
  • human immunodeficiency virus
  • human papillomavirus
  • polymorphism
access type Open Access

In vitro Effects of Prebiotics and Synbiotics on Apis cerana Gut Microbiota

Published Online: 20 Dec 2021
Page range: 511 - 520

Abstract

Abstract

This study aimed to investigate in vitro effects of the selected prebiotics alone, and in combination with two potential probiotic Lactobacillus strains on the microbial composition of Apis cerana gut microbiota and acid production. Four prebiotics, inulin, fructo-oligosaccharides, xylo-oligosaccharides, and isomalto-oligosaccharides were chosen, and glucose served as the carbon source. Supplementation of this four prebiotics increased numbers of Bifidobacterium and lactic acid bacteria while decreasing the pH value of in vitro fermentation broth inoculated with A. cerana gut microbiota compared to glucose. Then, two potential probiotics derived from A. cerana gut at different dosages, Lactobacillus helveticus KM7 and Limosilactobacillus reuteri LP4 were added with isomalto-oligosaccharides in fermentation broth inoculated with A. cerana gut microbiota, respectively. The most pronounced impact was observed with isomalto-oligosaccharides. Compared to isomalto-oligosaccharides alone, the combination of isomalto-oligosaccharides with both lactobacilli strains induced the growth of Bifidobacterium, LAB, and total bacteria and reduced the proliferation of Enterococcus and fungi. Consistent with these results, the altered metabolic activity was observed as lowered pH in in vitro culture of gut microbiota supplemented with isomalto-oligosaccharides and lactobacilli strains. The symbiotic impact varied with the types and concentration of Lactobacillus strains and fermentation time. The more effective ability was observed with IMO combined with L. helveticus KM7. These results suggested that isomalto-oligosaccharides could be a potential prebiotic and symbiotic with certain lactobacilli strains on A. cerana gut microbiota.

Keywords

  • isomalto-oligosaccharides
  • lactic acid bacteria
  • metabolic activity
access type Open Access

Lipoic Acid Does Not Affect The Growth of Mycoplasma hominis Cells In Vitro

Published Online: 20 Dec 2021
Page range: 521 - 526

Abstract

Abstract

Mycoplasma hominis is associated with various infections, for which the treatment can be complex. Lipoic acid (LA) plays a role as a cofactor in eukaryotes, most Bacteria, and some Archea. Research of recent years has increasingly pointed to the therapeutic properties of exogenously supplemented LA. The present study was conducted on 40 strains of M. hominis cultured with the following LA concentrations: 1,200 μg/ml, 120 μg/ml, and 12 μg/ml. The bacterial colonies of each strain were counted and expressed as the number of colony-forming units/ml (CFU). The number of CFU in M. hominis strains obtained in the presence of LA was compared with the number of CFU in the strains grown in the media without LA. The obtained results indicated that the presence of LA in the medium did not affect the growth of M. hominis. The investigation of the influence of LA on the growth and survival of microbial cells not only allows for obtaining an answer to the question of whether LA has antimicrobial activity and, therefore, can be used as a drug supporting the treatment of patients infected with a given pathogenic microorganism. Such studies are also crucial for a better understanding of LA metabolism in the microbial cells, which is also important for the search for new antimicrobial drugs. This research is, therefore, an introduction to such further studies.

Keywords

  • lipoic acid
  • lipoic acid metabolism in microbial cells
  • lipoyl carrier protein
10 Articles

mini-review

access type Open Access

Silent Genes: Antimicrobial Resistance and Antibiotic Production

Published Online: 16 Oct 2021
Page range: 421 - 429

Abstract

Abstract

Silent genes are DNA sequences that are generally not expressed or expressed at a very low level. These genes become active as a result of mutation, recombination, or insertion. Silent genes can also be activated in laboratory conditions using pleiotropic, targeted genome-wide, or biosynthetic gene cluster approaches. Like every other gene, silent genes can spread through horizontal gene transfer. Most studies have focused on strains with phenotypic resistance, which is the most common subject. However, to fully understand the mechanism behind the spreading of antibiotic resistance, it is reasonable to study the whole resistome, including silent genes.

Keywords

  • silent genes
  • antimicrobial resistance
  • spp.
  • mutations
access type Open Access

Can Lactobacillus spp. Be a Factor Reducing the Risk of Miscarriage?

Published Online: 06 Dec 2021
Page range: 431 - 446

Abstract

Abstract

Pregnancy loss is a common obstetric problem. Significant causes of miscarriage include genetic and epigenetic disorders of the embryo, immunological and endocrine factors, uterine malformations, improper embryo selection, and lifestyle. Perhaps a hitherto underappreciated cause of miscarriage may be an abnormal microbiota composition of the female reproductive system. Lactobacillus spp. is the most common bacteria within the reproductive tract. However, the protective role of Lactobacilli in the vagina has been well described in the literature, while it is still unknown what function Lactobacilli may have in the uterus. Moreover, new research shows that Lactobacillus spp. can have a role in miscarriage. However, both molecular and immunological mechanisms of host-Lactobacillus spp. interactions are not fully understood. Understanding these relationships will help address the importance and extent of the protective role of Lactobacillus spp. in miscarriage.

Keywords

  • miscarriage
  • pregnancy
  • uterine microbiota
  • vaginal microbiota

original-paper

access type Open Access

Chemical Components of Aqueous Extracts of Melia azedarach Fruits and Their Effects on The Transcriptome of Staphylococcus aureus

Published Online: 29 Oct 2021
Page range: 447 - 459

Abstract

Abstract

Staphylococcus aureus is the causative agent of numerous and varied clinical infections. Crude aqueous extracts of Melia azedarach fruits inhibit the planktonic growth and initial biofilm formation of S. aureus in a dose-dependent manner. Moreover, the biofilm topologies became sparse and decreased as the concentration of the aqueous extracts increased. RNA-Seq analyses revealed 532 differentially expressed genes (DEGs) after S. aureus exposure to 0.25 g/ml extracts; 319 of them were upregulated, and 213 were downregulated. The majority of DEGs were categorized into abundant sub-groups in the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Finally, untargeted UHPLC-MS/MS analyses of the aqueous extracts of M. azedarach fruits demonstrated a highly complex profile in positive and negative electrospray ionization modes. The extracts primarily consisted of lipids and lipid-like molecules, organic acids and their derivatives, phenylpropanoids, polyketides, organoheterocyclic compounds, and benzenoids annotated by abundant lipid maps and KEGG pathways. Overall, this study provides evidences that the aqueous extracts of M. azedarach fruits can control S. aureus infections and sought to understand the mode of action of these extracts on S. aureus.

Keywords

  • fruits
  • differentially expressed genes
  • biofilms
  • UHPLC-MS/MS
access type Open Access

QuantiFERON-TB Gold Plus Test in Diagnostics of Latent Tuberculosis Infection in Children Aged 1–14 in a Country with a Low Tuberculosis Incidence

Published Online: 06 Dec 2021
Page range: 461 - 468

Abstract

Abstract

The aim of the study was to evaluate the QuantiFERON-TB Gold Plus (QFT-Plus) test usability in the identification of latent tuberculosis infection (LTBI) in children and the determination of features associated with tuberculin skin test (TST) and QFT-Plus-positive results concerning LTBI. Two-hundred thirteen children aged 1–14 were screened for LTBI due to household contact with TB, suspected TB, or were qualified for biological therapy. The objective of this study was to evaluate the QFT-Plus affectivity as a diagnostic test in the absence of a gold standard (GS) test for the diagnosis of LTBI. The children were diagnosed with QFT-Plus, TST, and culture of TB. The QFT-Plus results were analyzed depending on the children’s age, TST size, and type. In children aged 1–4, the positive predictive value of QFT-Plus was 1, the negative predictive value was 0.94, QFT-Plus sensitivity was 75%, and specificity was 100%. It was observed that in children aged 5–14 years, the level of agreement decreased to the substantial, i.e., 87.2%. Moreover, the negative predictive value was 0.83. QFT-Plus sensitivity was 64%, and specificity was 100%. Statistical analysis of QFT-Plus and TST results showed substantial and almost perfect agreements. Our study suggests that QFT-Plus is helpful in a pediatric practice showing good sensitivity and specificity for LTBI. The BCG vaccine, infections, and concomitant morbidities do not affect QFT-Plus results.

Keywords

  • QuantiFERON-TB Gold Plus
  • tuberculin skin test
  • latent tuberculosis infection
  • tuberculosis
  • children
access type Open Access

Histopathological Analysis of Acinetobacter baumannii Lung Infection in a Mouse Model

Published Online: 20 Dec 2021
Page range: 469 - 477

Abstract

Abstract

Acinetobacter baumannii is the main causative pathogen of nosocomial infections that causes severe infections in the lungs. In this study, we analyzed the histopathological characteristics of lung infection with two strains of A. baumannii (ATCC 19606 and the clinical isolate TK1090) and Pseudomonas aeruginosa PAO-1 in C3H/HeN mice to evaluate the virulence of A. baumannii. Survival was evaluated over 14 days. At 1, 2, 5, or 14 days postinfection, mice of C3H/HeN were sacrificed, and histopathological analysis of lung specimens was also performed. Histopathological changes and accumulation of neutrophils and macrophages in the lungs after infection with A. baumannii and P. aeruginosa were analyzed. Following intratracheal inoculation, the lethality of ATCC 19606- and TK1090-infected mice was lower than that of PAO-1-infected mice. However, when mice were inoculated with a sub-lethal dose of A. baumannii, the lung bacterial burden remained in the mice until 14 days post-infection. Additionally, histopathological analysis revealed that macrophages infiltrated the lung foci of ATCC 19606-, TK1090-, and PAO-1-infected mice. Although neutrophils infiltrated the lung foci of ATCC 19606- and TK1090-infected mice, they poorly infiltrated the lung foci of PAO-1-infected mice. Accumulation of these cells in the lung foci of ATCC 19606- and TK1090-infected mice, but not PAO-1-infected mice, was observed for 14 days post-infection. These results suggest that A. baumannii is not completely eliminated despite the infiltration of immune cells in the lungs and that inflammation lasts for prolonged periods in the lungs. Further studies are required to understand the mechanism of A. baumannii infection, and novel drugs and vaccines should be developed to prevent A. baumannii infection.

Keywords

  • neutrophils
  • macrophages
  • a mouse lung infection model
access type Open Access

A Novel LysR Family Factor STM0859 is Associated with The Responses of Salmonella Typhimurium to Environmental Stress and Biofilm Formation

Published Online: 20 Dec 2021
Page range: 479 - 487

Abstract

Abstract

Salmonella enterica subsp. enterica serovar Typhimurium (ST) is an intracellularly parasitic bacterium. This zoonotic pathogen causes food poisoning and thus imposes a severe threat to food safety. Here, to understand the regulatory roles of the novel transcription factor STM0859 on the response of ST to environmental stress and biofilm formation, the STM0859 gene-deficient strain and the complementation strain ΔSTM0859/STM0859 were generated, respectively. Then, its capacity of responding to environmental stresses and biofilm (BF) formation ability under different stresses, including acid, alkali, high salt, cholate, and oxidative stresses was tested. We further analyzed the interaction between the STM0859 protein and the promoter of the acid stress response-related gene rcsB by performing an electrophoresis mobility shift assay (EMSA). The results showed that acid resistance and BF formation capacities of ST-ΔSTM0859 strain were significantly weaker, as compared with those of Salmonella Typhimurium SL1344 (ST-SL1344) wild strain (p < 0.01). Quantitative qRT-PCR analysis showed that the expression levels of acid stress and BF formation-related genes, rcsB and rpoS, of ST-ΔSTM0859 strain were significantly reduced at the transcription levels, while the transcription levels of these genes were fully restored in complementation strain ST-ΔSTM0859/STM0859. The results of EMSA showed that STM0859 was capable of binding the promoter DNA fragments of the rcsB gene, suggesting that STM0859 can promote the transcription of the rcsB gene through interaction with its promoter, thereby exerting an indirectly regulatory role on the adaptive responses to acid stress and BF formation of ST. This study provided new insights into the regulatory mechanisms of the LysR family factors on the tolerances of ST under adverse environmental stresses.

Keywords

  • Typhimurium
  • biofilm
  • environmental stress
  • gene
access type Open Access

Characteristics of the Cervicovaginal Microenvironment in Childbearing-Age Women with Different Degrees of Cervical Lesions and HR-HPV Positivity

Published Online: 20 Dec 2021
Page range: 489 - 500

Abstract

Abstract

Persistent infection with high-risk human papillomavirus (HR-HPV) is the most important determinate in the development of cervical cancer, and cervical microecology can modulate cervical viral infection. However, few studies have been conducted on the microecological analysis of cervical diseases using strict physiological factors. This study investigated the characteristics and dynamics of cervical microecology in childbearing-age Chinese women with different degrees of HR-HPV-positive cervical lesions. A total of 168 subjects were selected according to the selection criteria, including healthy HPV-negative individuals (n = 29), HR-HPV-infected individuals (n = 29), low-grade squamous intraepithelial lesion individuals (LSIL, n = 32), high-grade squamous intraepithelial lesion individuals (HSIL, n = 40), and cervical cancer individuals (n = 38). We sampled cervical secretions from each subject and performed comparative analysis using the 16S rRNA sequencing method. Comparison analysis showed that Lactobacillus and Ignatzschineria were the dominant genera in the healthy group, while Gardnerella and Prevotella were more enriched in the disease groups. Based on the taxa composition, we roughly divided the development of cervical cancer into two phases: phase I was from healthy status to HR-HPV infection and LSIL; phase II was from LSIL to HSIL and cervical cancer. Different interactions among different genera were observed in different groups. Prevotella inhibited the abundance of Lactobacillus in the healthy group, while Prevotella inhabited the abundance of Gardnerella in the other groups. In the HR-HPV infection group, Ignatzschineria and Enterococcus showed a positive interaction but dissociated with the increase in cervical lesions, which might eventually lead to a continuous decrease in the abundances of Lactobacillus and Ignatzschineria.

Keywords

  • cervical microorganisms
  • cervical lesions
  • 16S rRNA sequencing
access type Open Access

Identification of Genetic Variants of Human Papillomavirus in a Group of Mexican HIV/AIDS Patients and Their Possible Association with Cervical Cancer

Published Online: 20 Dec 2021
Page range: 501 - 509

Abstract

Abstract

Infections caused by the human immunodeficiency virus (HIV) and human papillomavirus (HPV) cause thousands of deaths worldwide each year. So far, there has been no consensus on whether there is a direct relationship between the incidence of neoplasms and the immunosuppression caused by HIV that could help understand if coinfection increases the likelihood of cervical cancer. The objective of the study was to identify the presence of genetic variants of HPV in a group of HIV-positive women and their possible association with cervical cancer. Cervical samples were taken from HIV-positive patients for cytological analysis to identify the HPV genotype by polymerase chain reaction (PCR) and sequencing. The most prevalent L1 capsid protein mutations in the HPV genotype were analyzed in silico. Various types of HPV were identified, both high-risk (HR) and low-risk (LR). The most prevalent genotype was HPV51. Analysis of the L1 gene sequences of HPV51 isolates showed nucleotide variations. Of the samples analyzed in Puebla, Mexico, HPV51 had the highest incidence (17.5%, 7/40). Different mutations, which could be used as population markers, were detected in this area, and they have not been reported in the L1 databases for HPV51 in Mexico. Genotypes 6, 14, 86, 87, 89, and 91, not detected or reported in samples from patients with HPV in Mexico, were also identified. Data from the population analyzed suggest no direct relationship between HIV immunosuppression and cervical cancer, regardless of the high- or low-risk HPV genotype. Furthermore, it is possible to develop regional population markers for the detection of HPV based on the mutations that occur in the sequence of nucleotides analyzed.

Keywords

  • cervical cancer
  • human immunodeficiency virus
  • human papillomavirus
  • polymorphism
access type Open Access

In vitro Effects of Prebiotics and Synbiotics on Apis cerana Gut Microbiota

Published Online: 20 Dec 2021
Page range: 511 - 520

Abstract

Abstract

This study aimed to investigate in vitro effects of the selected prebiotics alone, and in combination with two potential probiotic Lactobacillus strains on the microbial composition of Apis cerana gut microbiota and acid production. Four prebiotics, inulin, fructo-oligosaccharides, xylo-oligosaccharides, and isomalto-oligosaccharides were chosen, and glucose served as the carbon source. Supplementation of this four prebiotics increased numbers of Bifidobacterium and lactic acid bacteria while decreasing the pH value of in vitro fermentation broth inoculated with A. cerana gut microbiota compared to glucose. Then, two potential probiotics derived from A. cerana gut at different dosages, Lactobacillus helveticus KM7 and Limosilactobacillus reuteri LP4 were added with isomalto-oligosaccharides in fermentation broth inoculated with A. cerana gut microbiota, respectively. The most pronounced impact was observed with isomalto-oligosaccharides. Compared to isomalto-oligosaccharides alone, the combination of isomalto-oligosaccharides with both lactobacilli strains induced the growth of Bifidobacterium, LAB, and total bacteria and reduced the proliferation of Enterococcus and fungi. Consistent with these results, the altered metabolic activity was observed as lowered pH in in vitro culture of gut microbiota supplemented with isomalto-oligosaccharides and lactobacilli strains. The symbiotic impact varied with the types and concentration of Lactobacillus strains and fermentation time. The more effective ability was observed with IMO combined with L. helveticus KM7. These results suggested that isomalto-oligosaccharides could be a potential prebiotic and symbiotic with certain lactobacilli strains on A. cerana gut microbiota.

Keywords

  • isomalto-oligosaccharides
  • lactic acid bacteria
  • metabolic activity
access type Open Access

Lipoic Acid Does Not Affect The Growth of Mycoplasma hominis Cells In Vitro

Published Online: 20 Dec 2021
Page range: 521 - 526

Abstract

Abstract

Mycoplasma hominis is associated with various infections, for which the treatment can be complex. Lipoic acid (LA) plays a role as a cofactor in eukaryotes, most Bacteria, and some Archea. Research of recent years has increasingly pointed to the therapeutic properties of exogenously supplemented LA. The present study was conducted on 40 strains of M. hominis cultured with the following LA concentrations: 1,200 μg/ml, 120 μg/ml, and 12 μg/ml. The bacterial colonies of each strain were counted and expressed as the number of colony-forming units/ml (CFU). The number of CFU in M. hominis strains obtained in the presence of LA was compared with the number of CFU in the strains grown in the media without LA. The obtained results indicated that the presence of LA in the medium did not affect the growth of M. hominis. The investigation of the influence of LA on the growth and survival of microbial cells not only allows for obtaining an answer to the question of whether LA has antimicrobial activity and, therefore, can be used as a drug supporting the treatment of patients infected with a given pathogenic microorganism. Such studies are also crucial for a better understanding of LA metabolism in the microbial cells, which is also important for the search for new antimicrobial drugs. This research is, therefore, an introduction to such further studies.

Keywords

  • lipoic acid
  • lipoic acid metabolism in microbial cells
  • lipoyl carrier protein

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