Infective endocarditis by Enterobacter cloacae: a systematic review and meta-analysis

Camel urine as a potential source of bioactive molecules showing their efficacy against pathogens: A systematic review

Camels are highly suited for severe desert conditions and able to provide most of the natural products like urine, which has been used as alternative medicine to treat diverse infections and disorders. There is, however, a shortage and paucity of scientific reviews highlighting the antifungal, antibacterial and antiviral effects of camel urine. By better understanding its antimicrobial characteristics, our overarching aim is to provide an exhaustive overview of this valuable natural product by synthesizing and summarizing data on the efficacy of this biofluid and also describing the potential substances exhibiting antimicrobial properties. We searched three databases in order to point out relevant articles (Web of Science, Scopus and Google Scholar) until December 2022. Research articles of interest evaluating the antimicrobial effects of camel urine were selected. Overall, camel urine furnished promising antibacterial activities against gram-positive bacteria, namely Staphylococcus aureus (30 mm), Bacillus cereus (22 mm), Bacillus subtilis (25 mm) and Micrococcus luteus (21 mm), as well as gram-negative bacteria, especially Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter cloacae, and Salmonella spp., without forgetting its efficiency on Mycobacterium tuberculosis as well. The excretion also showed its potency against H1N1 virus, vesicular stomatitis virus and middle east respiratory syndrome coronavirus. Similarly, the camel urine featured strong antifungal activity against Candida albicans, Aspergillus niger, Aspergillus flavus and dermatophytes with a minimal inhibitory concentration of 0.625 μg/ml against Trichophyton violaceum, 2.5 μg/ml against Microsporum canis and 1.25 μg/ml against Trichophyton rubrum and Trichophyton mentagrophytes. This comprehensive review will be valuable for researchers interested in investigating the potential of camel urine in the development of novel broad-spectrum key molecules targeting a wide range of drug-resistant pathogenic microorganisms.

Enterobacter cloacae from urinary tract infections: frequency, protein analysis, and antimicrobial resistance

The genus Enterobacter belongs to the ESKAPE group, which includes Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. This group is characterized by the development of resistance to various antibiotics. In recent years, Enterobacter cloacae (E. cloacae) has emerged as a clinically important pathogen responsible for a wide range of healthcare-associated illnesses. Identifying Enterobacter species can be challenging due to their similar phenotypic characteristics. The emergence of multidrug-resistant E. cloacae is also a significant problem in healthcare settings. Therefore, our study aimed to identify and differentiate E. cloacae using Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) as a fast and precise proteomic analytical technique. We also tested hospital-acquired E. cloacae isolates that produce Extended-spectrum beta-lactamases (ESBL) against commonly used antibiotics for treating urinary tract infections (UTIs). We used a total of 189 E. cloacae isolates from 2300 urine samples of patients with UTIs in our investigation. We employed culturing techniques, as well as the BD Phoenix™ automated identification system (Becton, Dickinson) and Analytical Profile Index (API) system for the biochemical identification of E. cloacae isolates. We used the MALDI Biotyper (MBT) device for peptide mass fingerprinting analysis of all isolates. We utilized the single peak intensities and Principal Component Analysis (PCA) created by MBT Compass software to discriminate and cluster the E. cloacae isolates. Additionally, we evaluated the sensitivity and resistance of ESBL-E. cloacae isolates using the Kirby Bauer method. Out of the 189 E. cloacae isolates, the BD Phoenix system correctly identified 180 (95.24%) isolates, while the API system correctly identified 165 (87.30%) isolates. However, the MBT accurately identified 185 (98.95%) isolates with a score of 2.00 or higher. PCA positively discriminated the identified E. cloacae isolates into one group, and prominent peaks were noticed between 4230 mass-to-charge ratio (m/z) and 8500 m/z. The ESBL-E. cloacae isolates exhibited a higher degree of resistance to ampicillin, amoxicillin-clavulanate, cephalothin, cefuroxime, and cefoxitin. Several isolates were susceptible to carbapenems (meropenem, imipenem, and ertapenem); however, potential future resistance against carbapenems should be taken into consideration. In conclusion, MALDI-TOF MS is a powerful and precise technology that can be routinely used to recognize and differentiate various pathogens in clinical samples. Additionally, the growing antimicrobial resistance of this bacterium may pose a significant risk to human health.

Infective Endocarditis by Lactobacillus Species-A Narrative Review

Bacteria of the genus Lactobacillus are microaerophilic or aerotolerant anaerobic Gram-positive non-spore-forming rods. They are considered essential members of the human gut microbiome; however, recent studies have revealed that these microorganisms are less predominant in the gut microbiome than initially thought. Lactobacillus spp. is mainly known for its use as a probiotic in foods and supplements to prevent and treat specific issues such as infectious diseases, irritable bowel syndrome, and diabetes mellitus. However, Lactobacillus spp. may occasionally cause infections such as bacteremia or infective endocarditis (IE). The present study aimed to review all cases of IE by Lactobacillus spp. and describe the epidemiology, microbiology, clinical characteristics, treatment, and outcomes of this infection by collecting relevant data from studies existing in Pubmed and Scopus until 28 September 2023. A total of 77 studies containing data for 82 patients were included. The median age was 56 years, and 69.6% were male. A prosthetic valve was present in 16% of patients, and 17.3% had previously been on probiotics. The aortic valve was the most commonly involved intracardiac site, followed by the mitral valve. Fever, embolic phenomena, sepsis, and heart failure were the most common clinical presentations. Aminoglycosides and penicillin were the most commonly used antimicrobials for definitive treatment. Surgery was performed in 53.7% of patients. Overall mortality was 17.1%. IE in prosthetic valves and presentation with shock were independently associated with overall mortality.

Recent Records on Bacterial Opportunistic Infections via the Dietary Route

This narrative review was aimed at identifying the opportunistic bacterial pathogens that can be transmitted by contaminated food and represent a current threat for patients particularly susceptible to infections because of underlying conditions or predisposing factors. The analysis was focused on recent case or outbreak reports and systematic reviews published in the years 2019 to 2023 and resulted in sorting 24 bacterial groups comprising the genera or species able to cause a variety of systemic or invasive infections if ingested with food or drinking water. These included both bacteria known to cause mild infections in immunocompetent persons and bacteria considered to be innocuous, which are used in food fermentation or as probiotics. No recent cases of infections transmitted through dietary routes were reported for the critical nosocomial pathogens widely found in food products, primarily Acinetobacter baumannii and Klebsiella pneumoniae. However, the very first sources of their introduction into the clinical environment still need to be established. In many instances, risky dietary habits, such as eating raw fish, seafood, raw meat, unpasteurized milk, and their derived products or the lack of control in fermentation processes, has led to the reported illnesses, pointing out the necessity to improve the hygiene of production and consumer awareness of the risks.

Expanding germ-organ theory: Understanding non-communicable diseases through enterobacterial translocation

Diverse microbial communities colonize different habitats of the human body, including gut, oral cavity, nasal cavity and tissues. These microbial communities are known as human microbiome, plays a vital role in maintaining the health. However, changes in the composition and functions of human microbiome can result in chronic low-grade inflammation, which can damage the epithelial cells and allows pathogens and their toxic metabolites to translocate into other organs such as the liver, heart, and kidneys, causing metabolic inflammation. This dysbiosis of human microbiome has been directly linked to the onset of several non-communicable diseases. Recent metabolomics studies have revealed that pathogens produce several uraemic toxins. These metabolites can serve as inter-kingdom signals, entering the circulatory system and altering host metabolism, thereby aggravating a variety of diseases. Interestingly, Enterobacteriaceae, a critical member of Proteobacteria, has been commonly associated with several non-communicable diseases, and the abundance of this family has been positively correlated with uraemic toxin production. Hence, this review provides a comprehensive overview of Enterobacterial translocation and their metabolites role in non-communicable diseases. This understanding may lead to the identification of novel biomarkers for each metabolic disease as well as the development of novel therapeutic drugs.

Infective Endocarditis by Pasteurella Species: A Systematic Review

Pasteurella spp. are non-motile, facultative anaerobic, Gram-negative coccobacilli that are commonly found in the oral cavity and the gastrointestinal tract of some animals and are known to be the cause of infections. Usually, infections by Pasteurella spp. in humans is more common in the context of an animal bite leading to a skin and soft tissue infection (SSTI). Infective endocarditis (IE) is rarely caused by Pasteurella spp.; however, it can pose diagnostic and therapeutic dilemmas due to its rarity. The aim of the present study was to systematically review all cases of IE by Pasteurella spp. in the literature. A systematic review was performed of PubMed, Scopus and the Cochrane Library (through 20 December 2021) for studies providing data on epidemiology and clinical and microbiological characteristics as well as data on treatment and outcomes of IE by Pasteurella spp. A total of 28 studies containing data for 28 patients were included. Prosthetic valve was present in 21.4% of patients. The aorta was the most commonly involved intracardiac site. Fever, sepsis, septic shock and heart failure were the most common clinical presentations. Cephalosporins, aminopenicillins and penicillin were the antimicrobials used most commonly. Overall mortality was 17.9%.

Regulation of Host Immune Response against Enterobacter cloacae Proteins via Computational mRNA Vaccine Design through Transcriptional Modification

Enterobacter cloacae is mainly responsible for sepsis, urethritis, and respiratory tract infections. These bacteria may affect the transcription of the host and particularly their immune system by producing changes in their epigenetics. In the present study, four proteins of Enterobacter cloacae were used to predict the epitopes for the construction of an mRNA vaccine against Enterobacter cloacae infections. In order to generate cellular and humoral responses, various immunoinformatic-based approaches were used for developing the vaccine. The molecular docking analysis was performed for predicting the interaction among the chosen epitopes and corresponding MHC alleles. The vaccine was developed by combining epitopes (thirty-three total), which include the adjuvant Toll-like receptor-4 (TLR4). The constructed vaccine was analyzed and predicted to cover 99.2% of the global population. Additionally, in silico immunological modeling of the vaccination was also carried out. When it enters the cytoplasm of the human (host), the codon is optimized to generate the translated mRNA efficiently. Moreover, the peptide structures were analyzed and docked with TLR-3 and TLR-4. A dynamic simulation predicted the stability of the binding complex. The assumed construct was considered to be a potential candidate for a vaccine against Enterobacter cloacae infections. Hence, the proposed construct is suitable for in vitro analyses to validate its effectiveness.

Infective Endocarditis by Moraxella Species: A Systematic Review

Moraxella catarrhalis is the most clinically relevant species among Moraxella spp. For decades, it was considered to be part of the normal human flora in the upper respiratory tract. However, since the late 1970s, considerable evidence has proposed that M. catarrhalis is an important pathogen in the human respiratory tract. Even though Infective Endocarditis (IE) is rarely caused by Moraxella spp., these infections can be problematic due to the lack of experience in their management. The aim of this study was to systematically review all published cases of IE by Moraxella spp. A systematic review of PubMed, Scopus and Cochrane library (through 8 December 2021) for studies providing epidemiological, clinical, microbiological data as well as treatment data and outcomes of IE by Moraxella spp. was performed. A total of 27 studies, containing data for 31 patients, were included. A prosthetic valve was present in 25.8%. Mitral valve was the most commonly infected site. Fever, sepsis and embolic phenomena were the most common clinical presentations. Cephalosporins, aminoglycosides, aminopenicillins and penicillin were the most commonly used antimicrobials. Overall mortality was 12.9%.

Infective endocarditis by Serratia species: a systematic review

Serratia species are facultative anaerobes, non-spore-forming, motile Gram-negative bacteria. Serratia spp. are currently thought to cause a variety of infections, such as bacteremia, urinary tract infections, and pneumonia, as well as other, less common infections, including ocular infections or skin and soft tissue infections. On the other hand, Infective Endocarditis (IE) is an infrequent disease with notable morbidity and mortality. Even though IE is rarely caused by Serratia spp., these infections can be quite problematic due to the lack of experience in their management. This study aimed to systematically review all published cases of IE by Serratia spp. in the literature. A systematic review of PubMed, Scopus, and Cochrane library (through 13^th May 2021) for studies providing epidemiological, clinical, microbiological data as well as data on treatment and outcomes of IE by Serratia spp. was performed. In total, 50 studies, containing data for 72 patients, were included. A prosthetic valve was present in 18.1%. The mitral valve was the most commonly infected site, followed by the aortic valve. The diagnosis was facilitated by transthoracic echocardiography in 34.7%, while the diagnosis was set at autopsy in 22.4%. Fever, sepsis, and embolic phenomena were the most common clinical presentations, followed by heart failure. Aminoglycosides, cephalosporins, and carbapenems were the most commonly used antimicrobials. Clinical cure was noted only in 53.5%, while overall mortality was 47.2%. Having surgery along with antimicrobial treatment was independently associated with reduced overall mortality. IE by Serratia spp. was more likely to be associated with intravenous drug use, and to present with heart failure and embolic phenomena compared to IE by other non-HACEK Gram-negative bacilli, while mortality was also higher in IE by Serratia spp.