Coxiella burnetii is the agent of Q fever, or "query fever," a zoonosis first described in Australia in 1937. Since this first description, knowledge about this pathogen and its associated infections ...has increased dramatically. We review here all the progress made over the last 20 years on this topic. C. burnetii is classically a strict intracellular, Gram-negative bacterium. However, a major step in the characterization of this pathogen was achieved by the establishment of its axenic culture. C. burnetii infects a wide range of animals, from arthropods to humans. The genetic determinants of virulence are now better known, thanks to the achievement of determining the genome sequences of several strains of this species and comparative genomic analyses. Q fever can be found worldwide, but the epidemiological features of this disease vary according to the geographic area considered, including situations where it is endemic or hyperendemic, and the occurrence of large epidemic outbreaks. In recent years, a major breakthrough in the understanding of the natural history of human infection with C. burnetii was the breaking of the old dichotomy between "acute" and "chronic" Q fever. The clinical presentation of C. burnetii infection depends on both the virulence of the infecting C. burnetii strain and specific risks factors in the infected patient. Moreover, no persistent infection can exist without a focus of infection. This paradigm change should allow better diagnosis and management of primary infection and long-term complications in patients with C. burnetii infection.
The human gut microbiota is a metabolic organ that is determined by a dynamic process of selection and competition. Age, dietary habits and geographical origin of people have an important impact on ...the intestinal microbiota. The role of the microbiota is still largely unknown, but the bacteria of the gut flora do contribute enzymes that are absent in humans and play an essential role in the catabolism of dietary fibers. Germ-free mice provide a complementary approach for characterizing the properties of the human gut microbiota. Recently, microbial changes in the human gut were proposed to be one of the possible causes of obesity. This review summarizes the latest research on the association between microbial ecology and host weight.
No Such Thing as Chronic Q Fever Million, Matthieu; Raoult, Didier
Emerging infectious diseases,
05/2017, Volume:
23, Issue:
5
Journal Article
Peer reviewed
Open access
Modern diagnostic methods enable clinicians to look beyond a diagnosis of chronic Q fever and discern whether patients instead have persistent focalized Coxiella burnetii infection(s). Use of these ...methods and development of criteria to define and treat such infections, especially cardiovascular infections, will improve the prognosis for patients previously thought to have chronic Q fever.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Two third of COVID-19 patients do not complaint of a shortness of breath.•The LDCT scan showed signs compatible with pneumonia in two third of them.•Asymptomatic hypoxemia was present in one third ...of them at admission.•Patient with asymptomatic hypoxemia have a very poor outcome.•Lack of shortness of breath is not a sign of wellbeing in patient with COVID-19.
Describe and evaluate the outcome of a coronavirus disease-2019 (COVID-19) patient without shortness of breath.
We retrospectively collected data from COVID-19 patients diagnosed and cared for in Marseille, France. We selected data from patients who at admission, had a low dose CT scanner, dyspnea status, and oxygen saturation available. Blood gas was analyzed in a sample subset of patients.
Among 1712 patients with COVID-19, we report that 1107 (64.7%) do not complain of shortness of breath at admission. The low-dose computed tomography (LDCT) scan showed signs compatible with pneumonia in 757/1,107 (68.4%) of patients without dyspnea. In a subset of patients who had underwent at least one blood gas analysis (n = 161) and presented without dyspnea at admission, 28.1% (27/96) presented with a hypoxemia/hypocapnia syndrome. Asymptomatic hypoxia was associated with a very poor outcome (33.3% were transferred to the ICU and 25.9% died).
The absence of shortness of breath in an old patient with comorbidity merit medical attention and should not be considered as a good sign of well-being. The poor prognosis of asymptomatic hypoxia, highlight the severity of this mild clinical presentation. In these patients, pulse oximetry is an important mean to predict the outcome along with news score and LDCT scanner.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Obesity is associated with alteration of the gut microbiota. In order to clarify the effect of Lactobacillus-containing probiotics (LCP) on weight we performed a meta-analysis of clinical studies and ...experimental models. We intended to assess effects by Lactobacillus species.
A broad search with no date or language restriction was performed. We included randomized controlled trials (RCTs) and comparative clinical studies in humans and animals or experimental models assessing the effect of Lactobacillus-containing probiotics on weight. We primarily attempted to extract and use change from baseline values. Data were extracted independently by two authors. Results were pooled by host and by Lactobacillus species and are summarized in a meta-analysis of standardized difference in means (SMDs).
We identified and included 17 RCTs in humans, 51 studies on farm animals and 14 experimental models. Lactobacillus acidophilus administration resulted in significant weight gain in humans and in animals (SMD 0.15; 95% confidence intervals 0.05–0.25). Results were consistent in humans and animals. Lactobacillus fermentum and Lactobacillus ingluviei were associated with weight gain in animals. Lactobacillus plantarum was associated with weight loss in animals and Lactobacillus gasseri was associated with weight loss both in obese humans and in animals.
Different Lactobacillus species are associated different effects on weight change that are host-specific. Further studies are needed to clarify the role of Lactobacillus species in the human energy harvest and weight regulation. Attention should be drawn to the potential effects of commonly marketed lactobacillus-containing probiotics on weight gain.
► We performed a meta-analysis on weight gain effect of Lactobacillus probiotics. ► Comparative animal and human studies were included. ► Specific Lactobacillus species were associated with a weight gain effect. ► Other specific species showed a protective effect against obesity. ► Lactobacillus probiotics impact weight regulation with a species-specific pattern.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Gut microbial dysbiosis has been shown to be an instrumental factor in severe acute malnutrition (SAM) and particularly, the absence of Methanobrevibacter smithii, a key player in energy harvest. ...Nevertheless, it remains unknown whether this absence reflects an immaturity or a loss of the microbiota. In order to assess that, we performed a case-control study in Mali using a propensity score weighting approach. The presence of M. smithii was tested using quantitative PCR on faeces collected from SAM children at inclusion and at discharge when possible or at day 15 for controls. M. smithii was highly significantly associated with the absence of SAM, detected in 40.9% controls but only in 4.2% cases (p < 0.0001). The predictive positive value for detection of M. smithii gradually increased with age in controls while decreasing in cases. Among children providing two samples with a negative first sample, no SAM children became positive, while this proportion was 2/4 in controls (p = 0.0015). This data suggests that gut dysbiosis in SAM is not an immaturity but rather features a loss of M. smithii. The addition of M. smithii as a probiotic may thus represent an important addition to therapeutic approaches to restore gut symbiosis.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
We conducted this meta-analysis to determine the proportion of co-infection with influenza viruses in SARS-CoV-2 positive patients and to investigate the severity of COVID-19 in these patients. We ...included studies with SARS-CoV-2 infection confirmed by qRT-PCR and influenza virus infection (A and/or B) by nucleic acid tests. The proportion of co-infection was compared between children and adults, and between critically ill or deceased patients compared to overall patients. Fifty-four articles were included. The overall proportion of co-infection was 0.7%, 95%CI = 0.4 – 1.3. Most influenza co-infections were due to the influenza A virus (74.4%). The proportion of co-infection with influenza viruses among children (3.2%, 95% CI = 0.9 – 10.9) was significantly higher than that in adult patients (0.3%, 95% CI = 0.1 – 1.2), p-value <0.01. The proportion of co-infection with influenza viruses among critically ill patients tended to be higher than that in overall patients (2.2%, 95% CI = 0.3 – 22.4 versus 0.6%, 95% CI = 0.3 – 1.2, respectively, p-value = 0.22). Screening for pathogens in co-infection, particularly influenza viruses in patients infected with SARS-CoV-2, is necessary. This warrants close surveillance and investigation of the co-incidences and interactions of SARS-CoV-2 and other respiratory viruses, which is facilitated by the expansion of syndromic diagnosis approaches through the use of multiplex PCR assays.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Summary Background Q fever endocarditis caused by Coxiella burnetii is a potentially fatal disease characterised by a chronic evolution. To assess the long-term outcome and identify prognostic ...factors for mortality, surgical treatment, and serological changes in Q fever endocarditis, we did a retrospective study in the French National Referral Centre. Methods Patients included were diagnosed with Q fever endocarditis at our centre from May, 1983, to June, 2006, and followed up for a minimum of 3 years for each patient, history and clinical characteristics were recorded with a standardised questionnaire. Prognostic factors associated with death, surgery, serological cure, and serological relapse were assessed by Cox regression analysis. Excised heart valve analysis was assessed according to duration of treatment. Findings 104 patients were identified for inclusion in the study, although one was lost to follow-up; median follow-up was 100 months (range 37–310 months). 18 months of treatment was sufficient to sterilise the valves of all the patients except three, and 2 years of treatment sterilised all valves except one. In a multivariate Cox regression analysis, the major determinants associated with mortality were age (hazard ratio 1·11, 95% CI 1·05–1·18, p=0·003), stroke at diagnosis (7·09, 2·00–25·10, p=0·001), endocarditis on a prosthetic valve (6·04, 1·47–24·80, p=0·044), an absence of a four-times decrease of phase I IgG and IgA at 1 year (5·69, 1·00–32·22, p=0·049), or the presence of phase II IgM at 1 year (12·08, 3·11–46·85, p=0·005). Surgery was associated with heart failure (2·68, 1·21–5·94, p=0·015) or a cardiac abscess (4·71, 1·64–13·50, p=0·004). The determinants of poor serological outcome were male sex (0·47, 0·26–0·86, p=0·014), a high level of phase I IgG (0·65, 0·45–0·95, p=0·027), and a delay in the start of treatment with hydroxychloroquine (0·20, 0·04–0·91, p=0·037). Factors associated with relapse were endocarditis on a prosthetic valve (21·3, 2·05–221·86, p=0·01) or treatment duration less than 18 months (9·69, 1·08–86·72, p=0·042). Interpretation The optimum duration of treatment with doxycycline and hydroxychloroquine in Q fever endocarditis is 18 months for native valves and 24 months for prosthetic valves. This duration should be extended only in the absence of favourable serological outcomes. Patients should be serologically monitored for at least 5 years because of the risk of relapse. Funding French National Referral Centre for Q Fever.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Uncontrolled oxidative stress, reported in Salmonella and HIV infections, colorectal cancer or severe acute malnutrition, has been associated with anaerobic gut microbiome alteration, impaired ...butyrate production, mucosal immunity dysregulation and disruption of host-bacterial mutualism. However, the role of major antioxidant molecules in the human body, such as glutathione, ascorbic acid and uric acid, has been neglected in this context. Here, we performed an in vitro metabolomics study of the 3 most odorous anaerobic microbes isolated from the human gut in our laboratory (Clostridium sporogenes, Clostridium subterminale and Romboutsia lituseburensis) when grown in anaerobiosis or in aerobiosis with these 3 antioxidant molecules via gas and liquid chromatography-mass spectrometry (GC/MS and LC/MS). There was no growth or volatile organic compound production in aerobic cultures without the 3 antioxidant molecules. In anaerobiosis, the major metabolic products of the bacteria were thiols, alcohols and short-chain fatty acid esters. The production of alkanes, cycloheptatriene and, paradoxically, increased butyrate production, was observed in the cultures grown in aerobiosis with the 3 antioxidant molecules. The qualitative shift suggests specific molecular mechanisms that remain to be elucidated. The increased production of butyrate, but also isobutyrate and isovalerate in vitro suggests that these 3 antioxidant molecules contributed to the maintenance and active resilience of host-bacterial mutualism against mucosal oxygen and uncontrolled oxidative stress in vivo.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The etiological agent of COVID-19 SARS-CoV-2, is primarily a pulmonary-tropic coronavirus. Infection of alveolar pneumocytes by SARS-CoV-2 requires virus binding to the angiotensin I converting ...enzyme 2 (ACE2) monocarboxypeptidase. ACE2, present on the surface of many cell types, is known to be a regulator of blood pressure homeostasis through its ability to catalyze the proteolysis of Angiotensin II (Ang II) into Angiotensin-(1-7) Ang-(1-7). We therefore hypothesized that SARS-CoV-2 could trigger variations of ACE2 expression and Ang II plasma concentration in SARS-CoV-2-infected patients. We report here, that circulating blood cells from COVID-19 patients express less ACE2 mRNA than cells from healthy volunteers. At the level of circulating cells, this
gene dysregulation mainly affects the monocytes, which also show a lower expression of membrane ACE2 protein. Moreover, soluble ACE2 (sACE2) plasma concentrations are lower in prolonged viral shedders than in healthy controls, while the concentration of sACE2 returns to normal levels in short viral shedders. In the plasma of prolonged viral shedders, we also found higher concentrations of Ang II and angiotensin I (Ang I). On the other hand, the plasma levels of Ang-(1-7) remains almost stable in prolonged viral shedders but seems insufficient to prevent the adverse effects of Ang II accumulation. Altogether, these data evidence that the SARS-CoV-2 may affect the expression of blood pressure regulators with possible harmful consequences on COVID-19 outcome.
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