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Microbiology Spectrum May 2024The emergence of carbapenem-resistant strains poses a considerable challenge to global public health, and little is known about carbapenemase-producing strains in...
The emergence of carbapenem-resistant strains poses a considerable challenge to global public health, and little is known about carbapenemase-producing strains in Tianjin, China. This study aimed to investigate the risk factors for infections with carbapenem-resistant (CREC) strains. This retrospective case-control study was conducted at a tertiary teaching hospital. A total of 134 CREC clinical isolates were collected from the General Hospital of Tianjin Medical University between 2013 and 2020. The control group was selected at a ratio of 1:1 from patients with nosocomial carbapenem-susceptible infection. Risk factors for nosocomial CREC infection and clinical outcomes were analyzed using univariate and multivariate analyses. Multivariate analysis revealed that cephalosporin exposure (odd ratio OR = 2.01), carbapenem exposure (OR = 1.96), glucocorticoid exposure (OR = 32.45), and surgical history (OR = 3.26) were independent risk factors for CREC infection. The in-hospital mortality rate in the CREC group was 29.1%, and age >65 years (OR = 3.19), carbapenem exposure (OR = 3.54), and central venous catheter insertion (OR = 4.19) were independent risk factors for in-hospital mortality in patients with CREC infections. Several factors were identified in the development of nosocomial CREC infections. The CREC isolates were resistant to most antibiotics. Reducing CREC mortality requires a comprehensive consideration of appropriate antibiotic use, underlying diseases, and invasive procedures.IMPORTANCE is an opportunistic pathogen that causes severe hospital-acquired infections. The spread of carbapenem-resistant is a global threat to public health, and only a few antibiotics are effective against these infections. Consequently, these infections are usually associated with poor prognosis and high mortality. Therefore, understanding the risk factors associated with the causes and outcomes of these infections is crucial to reduce their incidence and initiate appropriate therapies. In our study, several factors were found to be involved in nosocomial carbapenem-resistant (CREC) infections, and CREC isolates were resistant to most antibiotics. Reducing CREC mortality needs a comprehensive consideration of whether antibiotics are used appropriately, underlying diseases, and invasive interventions. These findings provide valuable evidence for the development of anti-infective therapy, infection prevention, and control of CREC-positive infections.
PubMed: 38814065
DOI: 10.1128/spectrum.04228-23 -
Therapeutic Advances in Neurological... 2024Opportunistic viral infections in individuals with severe immunodeficiency can lead to fatal conditions such as progressive multifocal leukoencephalopathy (PML), for...
Opportunistic viral infections in individuals with severe immunodeficiency can lead to fatal conditions such as progressive multifocal leukoencephalopathy (PML), for which treatment options are limited. These infections pose significant risks, especially when co-infections with other viruses occur. We describe a combined therapy approach using directly isolated allogeneic Human Polyomavirus 1 (also known as BKV) and Epstein-Barr virus (EBV) specific cytotoxic T-cells for the treatment of PML in conjunction with identified EBV in the cerebrospinal fluid (CSF) of a male patient infected with human immunodeficiency virus (HIV). A 53-year-old HIV-positive male, recently diagnosed with PML, presented with rapidly worsening symptoms, including ataxia, tetraparesis, dysarthria, and dysphagia, leading to respiratory failure. The patient developed PML even after commencing highly active antiretroviral therapy (HAART) 3 months prior. Brain magnetic resonance imaging (MRI) revealed multifocal demyelination lesions involving the posterior fossa and right thalamus suggestive of PML. In addition to the detection of human polyomavirus 2 (also known as JCV), analysis of CSF showed positive results for EBV deoxyribonucleic acid (DNA). His neurological condition markedly deteriorated over the following 2 months. Based on MRI, there was no evidence of Immune Reconstitution Inflammatory Syndrome contributing to this decline. The patient did not have endogenous virus-specific T-cells. We initiated an allogeneic, partially human leukocyte antigen-matched transfer of EBV and utilizing the cross-reactivity between BKV and JCV-BKV specific T-cells. This intervention led to notable neurological improvement and partial resolution of the MRI lesions within 6 weeks. Our case of a patient with acquired immune deficiency syndrome demonstrates that PML and concurrent EBV co-infection can still occur despite undergoing HAART treatment. This innovative experimental therapy, involving a combination of virus-specific T-cells, was demonstrated to be an effective treatment option in this patient.
PubMed: 38813521
DOI: 10.1177/17562864241253917 -
Frontiers in Bioscience (Landmark... Apr 2024The antibiotic resistance of microorganisms is escalating rapidly. Infections caused by opportunistic pathogens in immunocompromised individuals have prompted...
BACKGROUND
The antibiotic resistance of microorganisms is escalating rapidly. Infections caused by opportunistic pathogens in immunocompromised individuals have prompted researchers to seek for potent and safe antibacterial agents. The purpose of this investigation was to explore the suppression of virulence gene expression, specifically the operon genes responsible in biofilm formation in , through the utilization of metabolites obtained from probiotic bacteria.
METHODS
To assess the antimicrobial properties, standard strains of five probiotic bacteria were tested against a standard strain of multidrug-resistant (MDR) employing the agar gel diffusion technique. Following the identification of the most potent probiotic strain (), the existence of its and genes was confirmed using the polymerase chain reaction (PCR) test. High-performance liquid chromatography (HPLC) and fourier-transform infrared spectroscopy (FTIR) techniques were employed to identify the intended metabolite, which was found to be a lipopeptide nature. The minimum inhibitory concentration (MIC) values and anti-biofilm activity of the targeted metabolite were determined using a dilution method in 96-well microplates and field emission scanning electron microscopy (FE-SEM). Real-time PCR (qPCR) was utilized for comparing the expression of operon genes, including , in pre- and post-exposure to the derived lipopeptide.
RESULTS
The MIC results indicated that the probiotic product inhibited the growth of at concentrations lower than those needed for conventional antibiotics. Furthermore, it was observed that the desired genes' expression decreased due to the effect of this substance.
CONCLUSIONS
This research concludes that the probiotic product could be a viable alternative for combating drug resistance in .
Topics: Acinetobacter baumannii; Probiotics; Anti-Bacterial Agents; Microbial Sensitivity Tests; Biofilms; Lipopeptides; Bacillus licheniformis; Drug Resistance, Multiple, Bacterial
PubMed: 38812307
DOI: 10.31083/j.fbl2905171 -
Respiratory Research May 2024Community-acquired pneumonia (CAP) is a common and serious condition that can be caused by a variety of pathogens. However, much remains unknown about how these...
BACKGROUND
Community-acquired pneumonia (CAP) is a common and serious condition that can be caused by a variety of pathogens. However, much remains unknown about how these pathogens interact with the lower respiratory commensals, and whether any correlation exists between the dysbiosis of the lower respiratory microbiota and disease severity and prognosis.
METHODS
We conducted a retrospective cohort study to investigate the composition and dynamics of sputum microbiota in patients diagnosed with CAP. In total, 917 sputum specimens were collected consecutively from 350 CAP inpatients enrolled in six hospitals following admission. The V3-V4 region of the 16 S rRNA gene was then sequenced.
RESULTS
The sputum microbiota in 71% of the samples were predominately composed of respiratory commensals. Conversely, 15% of the samples demonstrated dominance by five opportunistic pathogens. Additionally, 5% of the samples exhibited sterility, resembling the composition of negative controls. Compared to non-severe CAP patients, severe cases exhibited a more disrupted sputum microbiota, characterized by the highly dominant presence of potential pathogens, greater deviation from a healthy state, more significant alterations during hospitalization, and sparser bacterial interactions. The sputum microbiota on admission demonstrated a moderate prediction of disease severity (AUC = 0.74). Furthermore, different pathogenic infections were associated with specific microbiota alterations. Acinetobacter and Pseudomonas were more abundant in influenza A infections, with Acinetobacter was also enriched in Klebsiella pneumoniae infections.
CONCLUSION
Collectively, our study demonstrated that pneumonia may not consistently correlate with severe dysbiosis of the respiratory microbiota. Instead, the degree of microbiota dysbiosis was correlated with disease severity in CAP patients.
Topics: Humans; Community-Acquired Infections; Male; Female; Sputum; Middle Aged; Aged; Retrospective Studies; Severity of Illness Index; Longitudinal Studies; Microbiota; Cohort Studies; Dysbiosis; Pneumonia; Pneumonia, Bacterial; Aged, 80 and over; Adult
PubMed: 38811936
DOI: 10.1186/s12931-024-02821-2 -
Microbiology Spectrum May 2024The complex (Bcc) is a group of Gram-negative opportunistic bacteria often associated with fatal pulmonary infections in patients with impaired immunity, particularly...
Mutation of , encoding homogentisate 1,2-dioxygenase, is responsible for pyomelanin production but does not impact the virulence of in a chronic granulomatous disease mouse lung infection.
The complex (Bcc) is a group of Gram-negative opportunistic bacteria often associated with fatal pulmonary infections in patients with impaired immunity, particularly those with cystic fibrosis (CF) and chronic granulomatous disease (CGD). Some Bcc strains are known to naturally produce pyomelanin, a brown melanin-like pigment known for scavenging free radicals; pigment production has been reported to enable Bcc strains to overcome the host cell oxidative burst. In this work, we investigated the role of pyomelanin in resistance to oxidative stress and virulence in strains J2315 and K56-2, two epidemic CF isolates belonging to the ET-12 lineage. We previously reported that a single amino acid change from glycine to arginine at residue 378 in homogentisate 1,2-dioxygenase (HmgA) affects the pigment production phenotype: pigmented J2315 has an arginine at position 378, while non-pigmented K56-2 has a glycine at this position. Herein, we performed allelic exchange to generate isogenic non-pigmented and pigmented strains of J2315 and K56-2, respectively, and tested these to determine whether pyomelanin contributes to the protection against oxidative stress as well as in a respiratory infection in CGD mice . Our results indicate that the altered pigment phenotype does not significantly impact these strains' ability to resist oxidative stress with HO and NO and did not change the virulence and infection outcome in CGD mice suggesting that other factors besides pyomelanin are contributing to the pathophysiology of these strains.IMPORTANCEThe complex (Bcc) is a group of Gram-negative opportunistic bacteria that are often associated with fatal pulmonary infections in patients with impaired immunity, particularly those with cystic fibrosis and chronic granulomatous disease (CGD). Some Bcc strains are known to naturally produce pyomelanin, a brown melanin-like pigment known for scavenging free radicals and overcoming the host cell oxidative burst. We investigated the role of pyomelanin in strains J2315 (pigmented) and K56-2 (non-pigmented) and performed allelic exchange to generate isogenic non-pigmented and pigmented strains, respectively. Our results indicate that the altered pigment phenotype does not significantly impact these strains' ability to resist HO or NO and did not alter the outcome of a respiratory infection in CGD mice . These results suggest that pyomelanin may not always constitute a virulence factor and suggest that other features are contributing to the pathophysiology of these strains.
PubMed: 38809005
DOI: 10.1128/spectrum.00410-24 -
Journal of Research in Medical Sciences... 2024Type 2 diabetes mellitus (T2DM) is prone to opportunistic infections, including toxoplasmosis, due to an immunodeficiency system. This study aimed to evaluate the serum...
BACKGROUND
Type 2 diabetes mellitus (T2DM) is prone to opportunistic infections, including toxoplasmosis, due to an immunodeficiency system. This study aimed to evaluate the serum of people with T2DM to determine the titer of anti-toxoplasma antibodies in patients and compare it with the control group.
MATERIALS AND METHODS
720 blood samples have been carried out between October and the end of January 2017 in Sistan, and Baluchestan provinces in southeastern Iran, of these, 360 samples were related to healthy individuals (control), and 360 samples were related to T2DM individuals. The immunoglobulin (Ig) M and IgG enzyme-linked immunosorbent assay methods have been used to detect toxoplasmosis. The data were analyzed using SPSS-19, Chi-square, and Fisher's exact test to compare statistical parameters.
RESULTS
In this cross-sectional study, out of 360 samples of T2DM by ELISA method, 60% samples in diabetic patients and 48.1% in control group were IgG positive ( < 0.05). Nearly 2.5% samples in diabetic patients and 0.3% in control group were IgM positive ( < 0.05).
CONCLUSION
Anti-toxoplasma antibodies including IgG and IgM were higher in diabetic patient in comparison to control group.
PubMed: 38808216
DOI: 10.4103/jrms.jrms_49_23 -
Frontiers in Medicine 2024Adult respiratory distress syndrome due to viral pneumonia occurs predominantly in immunodeficient populations; adult respiratory distress syndrome secondary to human...
Adult respiratory distress syndrome due to viral pneumonia occurs predominantly in immunodeficient populations; adult respiratory distress syndrome secondary to human herpesvirus HHV-6 and HHV-7 pneumonia is extremely rare. Whipple's disease, caused by , a Gram-positive bacillus and obligate intracellular pathogen, is clinically challenging to diagnose. Whipple's disease is a chronic multisystem infectious disease caused by , most often affecting the gastrointestinal tract and joints, seldom the lungs. Both pathogens are opportunistic. We report a case of mixed infectious pneumonia in a patient with type 2 diabetes mellitus. The patient presented with dyspnea and intermittent fever. Imaging revealed multiple large patchy consolidations in the left lung. Routine anti-infective therapy was ineffective. Metagenomic next generation sequencing of bronchoalveolar lavage fluid indicated HHV-6 and HHV-7 pneumonia concurrent with and Streptococcus co-infections. Meropenem was administered to improve treatment. This case represents a rare mixed lung infection by multiple uncommon pathogens, and is of particular clinical significance.
PubMed: 38808139
DOI: 10.3389/fmed.2024.1375325 -
Frontiers in Cellular and Infection... 2024Among the genus, stands out as an important opportunistic infection causative agent commonly found in hospital settings, which poses a serious threat to human health....
Among the genus, stands out as an important opportunistic infection causative agent commonly found in hospital settings, which poses a serious threat to human health. Recently, the high prevalence of carbapenem-resistant isolates has created significant therapeutic challenges for clinicians. Bacteriophages and their derived enzymes are promising therapeutic alternatives or adjuncts to antibiotics effective against multidrug-resistant bacterial infections. However, studies investigating the depolymerases specific to strains are scarce. In this study, we identified and characterized a capsule depolymerase, Dpo27, encoded by the bacteriophage IME-Ap7, which targets . A total of 23 clinical isolates of spp. were identified as (21.91%, 23/105), and seven strains with various K locus (KL) types (KL14, KL32, KL38, KL111, KL163, KL207, and KL220) were used as host bacteria for phage screening. The lytic phage IME-Ap7 was isolated using 7 (KL220) as an indicator bacterium and was observed for depolymerase activity. A putative tail fiber gene encoding a polysaccharide-degrading enzyme (Dpo27) was identified and expressed. The results of the modified single-spot assay showed that both 7 and 1492 were sensitive to Dpo27, which was assigned the KL220 type. After incubation with Dpo27, strain was susceptible to killing by human serum; moreover, the protein displayed no hemolytic activity against erythrocytes. Furthermore, the protein exhibited sustained activity across a wide pH range (5.0-10.0) and at temperatures between 20 and 50°C. In summary, the identified capsule depolymerase Dpo27 holds promise as an alternative treatment for combating KL220-type infections.
Topics: Bacteriophages; Humans; Acinetobacter; Acinetobacter Infections; Glycoside Hydrolases; Bacterial Capsules
PubMed: 38808067
DOI: 10.3389/fcimb.2024.1373052 -
Frontiers in Cellular and Infection... 2024The genus harbors opportunistic pathogenic species, among which is pathogenic for honeybees although little studied. Recently, virulent strains of colonizing the...
The genus harbors opportunistic pathogenic species, among which is pathogenic for honeybees although little studied. Recently, virulent strains of colonizing the mite's mouth were found vectored into the honeybee body, leading to septicemia and death. also occurs as an opportunistic pathogen in the honeybee's gut with a low absolute abundance. The population seems controlled by the host immune system, but its presence may represent a hidden threat, ready to arise when honeybees are weakened by biotic and abiotic stressors. To shed light on the pathogen, this research aims at studying 's development dynamics in the honeybee body and its interactions with the co-occurring fungal pathogen . Firstly, the degree of pathogenicity and the ability to permeate the gut epithelial barrier of three strains, isolated from honeybees and belonging to different species (, , and ), were assessed by artificial inoculation of newborn honeybees with different doses (10, 10, and 10 cells/mL). The absolute abundance of in the gut and in the hemocoel was assessed in qPCR with primers targeting the gene. Moreover, the absolute abundance of was assessed in the gut of honeybees infected with at different development stages and supplied with beneficial microorganisms and fumagillin. Our results showed that all tested strains could pass through the gut epithelial barrier and proliferate in the hemocoel, with being the most pathogenic. Moreover, under cage conditions, better proliferates when a infection is co-occurring, with a positive and significant correlation. Finally, fumagillin and some of the tested beneficial microorganisms could control both and development. Our findings suggest a correlation between the two pathogens under laboratory conditions, a co-occurring infection that should be taken into consideration by researches when testing antimicrobial compounds active against , and the related honeybees survival rate. Moreover, our findings suggest a positive control of by the environmental microorganism in a in vivo model, confirming the potential of this specie as beneficial bacteria for honeybees.
Topics: Animals; Bees; Serratia; Nosema; Serratia marcescens; Gastrointestinal Tract; Serratia Infections; Cyclohexanes; Serratia liquefaciens; Fatty Acids, Unsaturated; Sesquiterpenes
PubMed: 38808063
DOI: 10.3389/fcimb.2024.1323157 -
Frontiers in Pediatrics 2024infection of the bloodstream and intestine is a rare and severe opportunistic infection in immunocompromised people. In Southwest China, we first reported a case of...
infection of the bloodstream and intestine is a rare and severe opportunistic infection in immunocompromised people. In Southwest China, we first reported a case of bloodstream and intestinal infection with multidrug-resistant (MDR) in a 4-year-old child with T-cell acute lymphoblastic leukemia. Blood and stool cultures were used to identify the infection. The selection of antibiotics was based on clinical expertise and medication sensitivity tests. We used linezolid, levofloxacin, and polymyxin B to treat the patient aggressively. infection is uncommon in juvenile acute lymphoblastic leukemia. Doctors should be aware of the likelihood of opportunistic infection during the post-chemotherapy bone marrow suppression period. We further conducted a review of the literature and performed a detailed analysis of s infection in pediatric leukemia. It is becoming increasingly apparent that antibiotic is abused domestically and abroad, resulting in the sharp increase of MDR bacteria. In general, most of the isolates are susceptible to third- or fourth-generation cephalosporins, aminoglycosides, quinolones, and carbapenem, but drug-resistant strains are being reported increasingly. We summarized the drug resistance rate of s caviae and in China in the last 10 years. Early recognition and effective treatment will improve prognosis and reduce mortality.
PubMed: 38803640
DOI: 10.3389/fped.2024.1233600