Posts filed under ‘Biología Molecular’

Ecological Analyses of Mycobacteria in Showerhead Biofilms and Their Relevance to Human Health

mBio 2018 September/October 2018 V.9 N.5 P.e01614-18

Matthew J. Gebert, Manuel Delgado-Baquerizo, Angela M. Oliverio, Tara M. Webster, Lauren M. Nichols, Jennifer R. Honda, Edward D. Chan, Jennifer Adjemian, Robert R. Dunn, Noah Fierer

Bacteria within the genus Mycobacterium can be abundant in showerheads, and the inhalation of aerosolized mycobacteria while showering has been implicated as a mode of transmission in nontuberculous mycobacterial (NTM) lung infections.

Despite their importance, the diversity, distributions, and environmental predictors of showerhead-associated mycobacteria remain largely unresolved.

To address these knowledge gaps, we worked with citizen scientists to collect showerhead biofilm samples and associated water chemistry data from 656 households located across the United States and Europe.

Our cultivation-independent analyses revealed that the genus Mycobacterium was consistently the most abundant genus of bacteria detected in residential showerheads, and yet mycobacterial diversity and abundances were highly variable.

Mycobacteria were far more abundant, on average, in showerheads receiving municipal water than in those receiving well water and in U.S. households than in European households, patterns that are likely driven by differences in the use of chlorine disinfectants.

Moreover, we found that water source, water chemistry, and household location also influenced the prevalence of specific mycobacterial lineages detected in showerheads.

We identified geographic regions within the United States where showerheads have particularly high abundances of potentially pathogenic lineages of mycobacteria, and these “hot spots” generally overlapped those regions where NTM lung disease is most prevalent. Together, these results emphasize the public health relevance of mycobacteria in showerhead biofilms.

They further demonstrate that mycobacterial distributions in showerhead biofilms are often predictable from household location and water chemistry, knowledge that advances our understanding of NTM transmission dynamics and the development of strategies to reduce exposures to these emerging pathogens.

FULL TEXT

https://mbio.asm.org/content/9/5/e01614-18

PDF

https://mbio.asm.org/content/mbio/9/5/e01614-18.full.pdf

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November 9, 2018 at 8:14 am

Identification of Epstein-Barr Virus in the Human Placenta and Its Pathologic Characteristics.

J Korean Med Sci. December 2017 V.32 N.12 P.1959-1966.   

Kim Y1,2, Kim HS3, Park JS3, Kim CJ4, Kim WH5.

1 Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.

2 Laboratory of Epigenetics, Cancer Research Institute, Seoul National University, Seoul, Korea.

3 Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea.

4 Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.

5 Department of Pathology, Seoul National University College of Medicine, Seoul, Korea. woohokim@snu.ac.kr

Abstract

Epstein-Barr virus (EBV), a common pathogen in humans, is suspected as the cause of multiple pregnancy-related pathologies including depression, preeclampsia, and stillbirth. Moreover, transmission of EBV through the placenta has been reported. However, the focus of EBV infection within the placenta has remained unknown to date. In this study, we proved the expression of latent EBV genes in the endometrial glandular epithelial cells of the placenta and investigated the cytological characteristics of these cells. Sixty-eight placentas were obtained from pregnant women. Tissue microarray was constructed. EBV latent genes including EBV-encoding RNA-1 (EBER1), Epstein-Barr virus nuclear antigen 1 (EBNA1), late membrane antigen (LMP1), and RPMS1 were detected with silver in situ hybridization and/or mRNA in situ hybridization. Nuclear features of EBV-positive cells in EBV-infected placenta were compared with those of EBV-negative cells via image analysis. Sixteen placentas (23.5%) showed positive expression of all 4 EBV latent genes; only the glandular epithelial cells of the decidua showed EBV gene expression. EBV infection status was not significantly correlated with maternal, fetal, or placental factors. The nuclei of EBV-positive cells were significantly larger, longer, and round-shaped than those of EBV-negative cells regardless of EBV-infection status of the placenta. For the first time, evidence of EBV gene expression has been shown in placental tissues. Furthermore, we have characterized its cytological features, allowing screening of EBV infection through microscopic examination.

PDF

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5680494/pdf/jkms-32-1959.pdf

November 9, 2018 at 7:06 am

Epstein-Barr Virus-Induced Mononucleosis as an Imitator of Severe Preeclampsia.

AJP Rep. January 2017 V.7 N.1 P.e5-e7.

Staley SA1, Smid MC2, Dotters-Katz SK2, Stringer EM2.

1 Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, North Carolina.

2 Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, North Carolina.

Abstract

Background In pregnancy, conditions presenting with hematologic abnormalities, transaminitis, and proteinuria pose diagnostic challenges in pregnancy. Case We present the case of an 18-year-old woman, G1P0, at 33 weeks’ gestation with fever of unknown cause, who developed progressively elevated liver enzymes, proteinuria, and thrombocytopenia, due to Epstein-Barr virus (EBV) infection. Conclusion Acute infection with EBV should be included in the differential diagnosis of preeclampsia with severe features, particularly in the setting of fever. Supportive treatment and observation may prevent iatrogenic preterm birth.

PDF

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5303016/pdf/10-1055-s-0036-1597265.pdf

November 9, 2018 at 7:05 am

Maternal depressive symptoms related to Epstein-Barr virus reactivation in late pregnancy.

Sci Rep. October 31, 2013 V.3 P.3096.

Zhu P1, Chen YJ, Hao JH, Ge JF, Huang K, Tao RX, Jiang XM, Tao FB.

1 1] Department of Maternal and Child Health, School of Public Health, Anhui Medical University, Hefei, China [2].

Abstract

We examined the relationship between maternal depressive symptoms in late pregnancy and Epstein-Barr virus reactivation before delivery. In this prospective observational study, prevalence of Epstein-Barr virus reactivation within one week before delivery was compared between 163 pregnant women with depressive symptoms at 33 to 34 weeks of gestation and a computer-generated control group of 163 pregnant healthy women without depressive symptoms. Depressive symptoms at 33 to 34 weeks of gestation were significantly related to the prevalence of Epstein-Barr virus reactivation before delivery after adjustment for potential confounders (adjusted OR = 2.74, 95%CI: 1.23-6.08). Compared to that in the control group, the prevalence of Epstein-Barr virus reactivation was higher in women with depressive symptoms accompanied by higher negative coping (24.2% compared with 7.9%; adjusted OR = 3.67, 95%CI: 1.47-9.16). Maternal depressive symptoms in late pregnancy are associated with Epstein-Barr virus reactivation, and this association could be moderated by maternal coping style.

PDF

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3813936/pdf/srep03096.pdf

November 9, 2018 at 7:04 am

IMAGES IN CLINICAL MEDICINE – Spinal Brucellosis

N Engl J of Med October 25, 2018 V.379 P.e28

Christine Cho, M.D., and Michihiko Goto, M.D.

A 62-year-old man presented to the emergency department with a 6-month history of worsening low back pain, fevers, chills, night sweats, and weight loss. He regularly traveled to Mexico and had occasionally consumed unprocessed dairy products. He had no history of tuberculosis infection or known exposure. Laboratory studies revealed a white-cell count of 10,600 per cubic millimeter (reference range, 3700 to 10,500) and an erythrocyte sedimentation rate of 65 mm per hour (reference range, 0 to 15)…..

FULL TEXT

https://www.nejm.org/doi/full/10.1056/NEJMicm1803513?query=infectious-disease

PDF

https://www.nejm.org/doi/pdf/10.1056/NEJMicm1803513

November 6, 2018 at 8:19 am

Culture of Bone Biopsy Specimens Overestimates Rate of Residual Osteomyelitis After Toe or Forefoot Amputation.

J Bone Joint Surg Am. September 5, 2018 V.100 N.17 P.1448-1454.

Mijuskovic B1, Kuehl R1, Widmer AF1, Jundt G1, Frei R1, Gürke L1, Wolff T1.

Abstract

BACKGROUND:

Guidelines recommend both histological analysis and culture for definite diagnosis of osteomyelitis. It is not clear if histological and culture criteria can be used interchangeably in the clinical scenario of toe amputation. We therefore prospectively compared the results of intraoperative culture and those of histological examination in this setting.

METHODS:

Consecutive patients requiring toe or forefoot amputation at the University Hospital Basel during a 2-year period were included in the study. Biopsy specimens from the residual bone were cultured according to microbiological standards. Histological analysis was performed using standardized criteria for osteomyelitis. Clinical outcomes were assessed retrospectively via chart review.

RESULTS:

Of 51 patients included in the study, 33 (65%) had a positive culture of residual bone and 14 (27%) showed histological signs of osteomyelitis. A negative histological result but a positive culture was found for 21 (41%) of the patients, suggesting that culture has a high false-positive rate if histological analysis is used as the reference to rule out osteomyelitis. The recommended criteria of both positive histological findings and positive culture were fulfilled by 12 (24%) of the 51 patients.

CONCLUSIONS:

Positive cultures of residual bone after forefoot or toe amputation overestimate the true rate of osteomyelitis as defined by histological analysis, presumably because of contamination from soft tissue at the time of surgery. Additional studies are needed to evaluate the indications for, and the duration of, antibiotic treatment according to these findings.

CLINICAL RELEVANCE:

Our results cast doubt on the strategy of relying solely on culture of bone biopsy specimens when deciding whether antibiotic treatment for osteomyelitis is necessary after toe or forefoot amputation.

PDF

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6125752/pdf/jbjsam-100-1448.pdf

 

October 11, 2018 at 8:15 am

Control of a multi-hospital outbreak of KPC-producing Klebsiella pneumoniae type 2 in France, September to October 2009.

Euro Surveill. December 2, 2010 V.15 N.48. pii: 19734.

Carbonne A1, Thiolet JM, Fournier S, Fortineau N, Kassis-Chikhani N, Boytchev I, Aggoune M, Seguier JC, Senechal H, Tavolacci MP, Coignard B, Astagneau P, Jarlier V.

Abstract

An outbreak of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae type 2 was detected in September 2009 in two hospitals in a suburb south of Paris, France. In total, 13 KPC-producing K. pneumoniae type 2 cases (four with infections and nine with digestive-tract colonisations) were identified, including a source case transferred from a Greek hospital. Of the 13 cases, seven were secondary cases associated with use of a contaminated duodenoscope used to examine the source case (attack rate: 41%) and five were secondary cases associated with patient-to-patient transmission in hospital. All isolated strains from the 13 patients: (i) exhibited resistance to all antibiotics except gentamicin and colistin, (ii) were more resistant to ertapenem (minimum inhibitory concentration (MIC) always greater than 4 mg/L) than to imipenem (MIC: 1–8 mg/L, depending on the isolate), (iii) carried the blaKPC-2 and blaSHV12 genes and (iv) had an indistinguishable pulsed-field gel electrophoresis (PFGE) pattern. These cases occurred in three hospitals: some were transferred to four other hospitals. Extended infection control measures implemented in the seven hospitals included: (i) limiting transfer of cases and contact patients to other wards, (ii) cohorting separately cases and contact patients, (iii) reinforcing hand hygiene and contact precautions and (iv) systematic screening of contact patients. Overall, 341 contact patients were screened. A year after the outbreak, no additional case has been identified in these seven hospitals. This outbreak emphasises the importance of rapid identification and notification of emerging highly resistant K. pneumoniae strains in order to implement reinforced control measures

FULL TEXT

https://www.eurosurveillance.org/content/10.2807/ese.15.48.19734-en

October 10, 2018 at 1:00 pm

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