Pathogenic relevance of Lactobacillus: a retrospective review of over 200 cases

Necrotising fasciitis with extensive necrosis caused by Lactobacillus: a case report

BACKGROUND

Necrotising fasciitis (NF) is a life-threatening soft-tissue infection that rapidly destroys the epidermis, subcutaneous tissue, and fascia. Despite their low virulence, Lactobacillus spp. can cause NF, and because of its rare incidence, there is limited information about its molecular and clinicopathological characteristics. We report a rare case of NF in a patient with type 2 diabetes mellitus diagnosed on admission and severe obesity due to infection with two types of Lactobacillus spp. that manifested in extensive necrosis.

CASE PRESENTATION

A 48-year-old woman was referred to our hospital with a complaint of difficulty walking due to severe bilateral thigh pain. She presented with mild erythema, swelling, and severe skin pain extending from the pubic region to the groin. The patient was morbidly obese, had renal dysfunction, and had diabetes mellitus diagnosed on admission.; her LRINEC (Laboratory Risk Indicator for Necrotising Fasciitis) score was 9, indicating a high risk of NF. An exploratory surgical incision was made, and NF was diagnosed based on fascial necrosis. Emergent surgical debridement was performed, and cultures of the tissue culture and aspirated fluid/pus revealed two types of Lactobacillus spp.: Lactobacillus salivarius and L. iners. The patient was admitted to the intensive care unit (ICU), where antibiotics were administered and respiratory and circulatory management was performed. Diabetic ketoacidosis was detected, which was treated by controlling the blood glucose level stringently via intravenous insulin infusion. The patient underwent a second debridement on day 11 and a skin suture and skin grafting on day 36. The patient progressed well, was transferred from the ICU to the general ward on day 41, and was discharged unassisted on day 73.

CONCLUSIONS

Lactobacillus spp. are rarely pathogenic to healthy individuals and can scarcely trigger NF. However, these bacteria can cause rare infections such as NF in immunocompromised individuals, such as those with diabetes and obesity, and an early diagnosis of NF is imperative; surgical intervention may be required for the prevention of extensive necrosis. The LRINEC score may be useful for the early diagnosis of NF, even for less pathogenic bacteria such as Lactobacillus.

A first characterization of the microbiota-resilience link in swine

BACKGROUND

The gut microbiome plays a crucial role in understanding complex biological mechanisms, including host resilience to stressors. Investigating the microbiota-resilience link in animals and plants holds relevance in addressing challenges like adaptation of agricultural species to a warming environment. This study aims to characterize the microbiota-resilience connection in swine. As resilience is not directly observable, we estimated it using four distinct indicators based on daily feed consumption variability, assuming animals with greater intake variation may face challenges in maintaining stable physiological status. These indicators were analyzed both as linear and categorical variables. In our first set of analyses, we explored the microbiota-resilience link using PERMANOVA, α-diversity analysis, and discriminant analysis. Additionally, we quantified the ratio of estimated microbiota variance to total phenotypic variance (microbiability). Finally, we conducted a Partial Least Squares-Discriminant Analysis (PLS-DA) to assess the classification performance of the microbiota with indicators expressed in classes.

RESULTS

This study offers four key insights. Firstly, among all indicators, two effectively captured resilience. Secondly, our analyses revealed robust relationship between microbial composition and resilience in terms of both composition and richness. We found decreased α-diversity in less-resilient animals, while specific amplicon sequence variants (ASVs) and KEGG pathways associated with inflammatory responses were negatively linked to resilience. Thirdly, considering resilience indicators in classes, we observed significant differences in microbial composition primarily in animals with lower resilience. Lastly, our study indicates that gut microbial composition can serve as a reliable biomarker for distinguishing individuals with lower resilience.

CONCLUSION

Our comprehensive analyses have highlighted the host-microbiota and resilience connection, contributing valuable insights to the existing scientific knowledge. The practical implications of PLS-DA and microbiability results are noteworthy. PLS-DA suggests that host-microbiota interactions could be utilized as biomarkers for monitoring resilience. Furthermore, the microbiability findings show that leveraging host-microbiota insights may improve the identification of resilient animals, supporting their adaptive capacity in response to changing environmental conditions. These practical implications offer promising avenues for enhancing animal well-being and adaptation strategies in the context of environmental challenges faced by livestock populations. Video Abstract.

Oral Postbiotics as a Therapeutic Strategy for Atopic Dermatitis: A Systematic Review of Randomized Controlled Trials

Atopic dermatitis (AD) is a prevalent chronic skin disease affecting all age groups. The connection with the gut microbiome led to oral probiotics as a therapeutic strategy. However, being viable microorganisms, probiotics might present risks. Thus, non-viable postbiotics have been considered as an alternative. We aimed to evaluate the efficacy of oral Lactobacillus postbiotics for managing symptoms of AD in pediatric and adult patients. A systematic review was conducted following PRISMA guidelines. Nine randomized controlled trials assessing the effects of non-viable Lactobacillus spp. administered orally to patients diagnosed with AD were included in the review, in which 512 subjects were evaluated after the intervention. Most studies allowed the concomitant usage of corticosteroids. Three studies focused on adults and indicated symptom improvement. In contrast, three out of six trials evaluating pediatric patients did not report postbiotics-favoring results. The dosage seems to be relevant for outcome determination. Two trials compared postbiotics with their viable analogs, and only one reported positive results in both groups. Postbiotics-associated shifts in gut microbial communities were reported in one trial. Mild adverse effects were detected by a single study. The overall results suggested that Lactobacillus postbiotics might be successfully used as adjuvant AD therapy in adults. Thus far, data do not indicate efficacy in pediatric patients. Standardizing nomenclatures and experimental procedures, as well as expanding the studies to more geographic locations and assessing comprehensively the effects on the gut microbiome would provide better perspectives of postbiotics as a therapeutic option for AD.

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.

Lactobacillus paracasei R3 Alleviates Tumor Progression in Mice with Colorectal Cancer

Lactobacillus paracasei (L. paracasei), a common probiotic lactobacillus, has important functions in the food industry and human health. However, different strains of L. paracasei inevitably show differences in activity and colonization resistance, leading to differentiation in their functions, as well as their physical or chemical properties. The purpose of this study was to evaluate the characteristics of L. paracasei R3 (L.p R3) isolated from healthy human feces and determine whether the criteria for edible probiotics is met. The hemolysis type, biofilm-forming ability, antibiotic susceptibility, toxicity, and effective activity of L.p R3 were determined by establishing its probiotic activity traits in vitro and in vivo. The results showed that L.p R3 had a moderate biofilm formation ability, was sensitive to 11 antibiotics, was resistant to eight antibiotics, and was not hemolytic. The culture characteristics, morphology, and biochemical responses of the strain were consistent with the seed batch characteristics. In toxicity assays, L.p R3-fed mice showed no abnormalities in body weight, growth, or various organs. Additionally, L.p R3 was found to be effective in the prevention and treatment of colorectal cancer. In conclusion, our results revealed that L.p R3 has potential value as an edible probiotic without toxic side effects and alleviated the tumor progression of colorectal cancer in mice.

A Comparative Analysis of the Stomach, Gut, and Lung Microbiomes in Rattus norvegicus

Urban rats serve as reservoirs for several zoonotic pathogens that seriously endanger public health, destroy stored food, and damage infrastructure due to their close interaction with humans and domestic animals. Here, we characterize the core microbiomes of R. norvegicus's stomach, gut, and lung using 16S rRNA next-generation Illumina HiSeq sequencing. The USEARCH software (v11) assigned the dataset to operational taxonomic units (OTUs). The alpha diversity index was calculated using QIIME1, while the beta diversity index was determined using the Bray-Curtis and Euclidean distances between groups. Principal component analyses visualized variation across samples based on the OTU information using the R package. Linear discriminant analysis, effect sizes (LEfSe), and phylogenetic investigation were used to identify differentially abundant taxa among groups. We reported an abundance of microbiota in the stomach, and they shared some of them with the gut and lung microbiota. A close look at the microbial family level reveals abundant Lactobacillaceae and Bifidobacteriaceae in the stomach, whereas Lactobacillaceae and Erysipelotrichaceae were more abundant in the gut; in contrast, Alcaligenaceae were abundant in the lungs. At the species level, some beneficial bacteria, particularly Lactobacillus reuteri and Lactobacillus johnsonii, and some potential pathogens, such as Bordetella hinzii, Streptococcus parauberis, Porphyromonas pogonae, Clostridium perfringens, etc., were identified in stomach, gut, and lung samples. Moreover, the alpha and beta diversity indexes revealed significant differences between the groups. Further analysis revealed abundant differential taxonomic biomarkers, i.e., increased Prevotellaceae and Clostridia in the lungs, whereas Campylobacteria and Lachnospirales were richest in the stomachs. In conclusion, we identified many beneficial, opportunistic, and highly pathogenic bacteria, confirming the importance of urban rats for public health. This study recommends a routine survey program to monitor rodent distribution and the pathogens they carry and transmit to humans and other domestic mammals.

Bacteraemia caused by Lactobacillus casei in a patient after cardiac surgery. A case report

BACKGROUND

Bacteria of the Lactobacillus family are a part of the physiological flora of the oral cavity, gastrointestinal tract, and urinary tract. We have used them in the food industry as probiotics and supplements. In some settings, rod-shaped lactic acid bacteria may become pathogenic. It may occur in immunocompromised or heart disease patients after cardiac surgery, patients with disturbed intestinal wall permeability, or those treated with broad-spectrum antibiotics.

CASE PRESENTATION

We present rare bacteraemia induced by the probiotic bacterium Lactobacillus casei in a 63-year-old patient after the attempted removal of ICD electrodes, complicated by acute regurgitation of the tricuspid valve. The patient underwent urgent cardiac surgery, the electrode elements were removed, and the tricuspid valve was replaced with a biological prosthesis. After surgery, the patient required intensive, multidisciplinary treatment with mechanical ventilation, continuous renal replacement therapy, broad-spectrum empirical antibiotic therapy, parenteral nutrition, and blood product transfusion because of multiple organ failure. On the 14th day of hospitalisation, the clinical symptoms of septic shock were observed. The microbiological investigation was performed, and Lactobacillus casei was cultured from a dialysis catheter sample. Dedicated antimicrobials were administered, and the patient was discharged home in good overall condition.

CONCLUSIONS

The present case shows that the promoted use of probiotics must be cautiously administered to patients in severe conditions, especially when accompanied by reduced immune system efficiency symptoms.

An Unusual Case of Acute Cholecystitis Caused by Lactobacillus paracasei

Lactobacillus paracasei is a gram-positive rod commonly found in probiotic foods and is well known to promote healthy gastrointestinal tracts. However, there have been a few case reports that have found Lactobacillus paracasei to be the causative agent in complications such as endocarditis, meningitis, peritonitis, pancreatitis, and cholecystitis. We present the case of a 76-year-old woman who was admitted for decompensated heart failure. The patient also reported abdominal pain in the right upper quadrant. Ultrasound findings suggested cholelithiasis and a subsequent hepatobiliary iminodiacetic acid (HIDA) scan confirmed acute cholecystitis. This patient was not a good candidate for cholecystectomy because of the risk of cardiac complications. Hence, percutaneous cholecystostomy tube (PCT) placement was done, and the aspirate drained during the procedure was sent for pathology. This bile culture was positive for Lactobacillus paracasei and negative for any other kinds of bacteria. The incidence of Lactobacillus species-induced cholecystitis makes up only 0.08% to 0.2% of cases, which makes this an unusual case of acute cholecystitis caused by Lactobacillus paracasei. We will discuss several pathogenic aspects of Lactobacillus paracasei, such as its ability to generate biofilms, pore-forming toxins, drug transporters, and antibiotic susceptibility.

A case of Lactobacillus jensenii associated native valve endocarditis

Lactobacillus jensenii is rarely reported as a cause of endocarditis in immunocompetent patients. We describe a case of Lactobacillus jensenii associated native valve endocarditis that was identified using matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) technology. While most Lactobacillus species are generally resistant to vancomycin, Lactobacillus jensenii is frequently susceptible, but treatment requires accurate susceptibility results followed by timely medical and surgical intervention. Probiotic use in patients can be a risk factor for infection with Lactobacillus species.

Lactobacillus Bacteremia and Probiotics: A Review

Lactobacilli are widely found in nature, are commensal microbes in humans, and are commonly used as probiotics. Concerns about probiotic safety have arisen due to reports of bacteremia and other Lactobacillus-associated infections. We reviewed the literature for articles on the pathogenicity of Lactobacillus spp. bacteremia and reports of probiotics in these patients. Our aim is to review these articles and update the present knowledge on the epidemiology of Lactobacillus spp. bacteremia and determine the role of probiotics in Lactobacillus bacteremia. Lactobacillus bacteremia is infrequent but has a higher risk of mortality and risk factors, including severe underlying diseases, immune system suppression, admission to intensive care units, and use of central venous catheters. A variety of Lactobacillus species may cause bacteremia and may or may not be associated with probiotic exposure. To determine if oral probiotics are the source of these infections, the blood isolates and the oral probiotic strain(s) must be compared by sensitive identification methods. The prevalence of Lactobacillus bacteremia is infrequent but is more common in patients taking probiotics compared to those not taking probiotics. Three probiotics (Lacticaseibacillus rhamnosus GG, Lactiplantibacillus plantarum, and Lacticaseibacillus paracasei) were directly linked with blood isolates from bacteremia patients using molecular identification assays.

Lactobacillus rhamnosus endocarditis associated with dental procedure in a patient with Marfan's variant and prior aortic root replacement

A man in his 60s with a medical history of Marfan's variant with remote valve sparing aortic root replacement presented for evaluation of subacute fevers, chills and night sweats. He had no significant preceding history other than a dental cleaning performed with antibiotic prophylaxis. Blood cultures grew Lactobacillus rhamnosus which was susceptible to penicillin and linezolid but resistant to meropenem and vancomycin. A transthoracic echocardiogram showed an aortic leaflet vegetation with chronic moderate aortic regurgitation but no reduction in his ejection fraction. He was discharged home and treated with gentamicin and penicillin G, initially with adequate response. However, he was subsequently readmitted for persistent fevers, chills, weight loss and dizziness, found to have multiple acute strokes secondary to septic thromboemboli. He underwent definitive aortic valve replacement with excised tissue confirming infective endocarditis.

Bioinformatics and its role in the study of the evolution and probiotic potential of lactic acid bacteria

Due to their numerous well-established applications in the food industry, there have been many studies regarding the adaptation and evolution of lactic acid bacteria (LAB) in a wide variety of hosts and environments. Progress in sequencing technology and continual decreases in its costs have led to the availability of LAB genome sequence data. Bioinformatics has been central to the extraction of valuable information from these raw genome sequence data. This paper presents the roles of bioinformatics tools and databases in understanding the adaptation and evolution of LAB, as well as the bioinformatics methods used in the initial screening of LAB for probiotic potential. Moreover, the advantages, challenges, and limitations of employing bioinformatics for these purposes are discussed.

Meropenem resistant Lactobacillus endocarditis in an immunocompetent patient

Lactobacilli are gram-positive bacteria usually found in the normal flora and are commonly used as probiotic treatments for vaginal candidiasis. Lactobacilli are normally considered non-pathogenic; however, certain risk factors can make a patient susceptible to severe infections. This case describes an immunocompetent 61-year-old female with an automated intracardiac defibrillator who presented with a 10-day history of nausea and vomiting. Furthermore, diagnostic tests, including a transesophageal echocardiography, revealed a large vegetation, and blood cultures were consistently positive for Lactobacillus. The patient was treated with intravenous penicillin and gentamicin, along with removal of the automated intracardiac defibrillator. In patients with significant underlying conditions, physicians should consider Lactobacillus as a causative organism to avoid delays in treatment.

Commercial probiotic products in public health: current status and potential limitations

Consumption of commercial probiotics for health improvement and disease treatment has increased in popularity among the public in recent years. The local shops and pharmacies are brimming with various probiotic products such as probiotic food, dietary supplement and pharmaceuticals that herald a range of health benefits, from nutraceutical benefits to pharmaceutical effects. However, although the probiotic market is expanding rapidly, there is increasing evidence challenging it. Emerging insights from microbiome research and public health demonstrate several potential limitations of the natural properties, regulatory frameworks, and market consequences of commercial probiotics. In this review, we highlight the potential safety and performance issues of the natural properties of commercial probiotics, from the genetic level to trait characteristics and probiotic properties and further to the probiotic-host interaction. Besides, the diverse regulatory frameworks and confusing probiotic guidelines worldwide have led to product consequences such as pathogenic contamination, overstated claims, inaccurate labeling and counterfeit trademarks for probiotic products. Here, we propose a plethora of available methods and strategies related to strain selection and modification, safety and efficacy assessment, and some recommendations for regulatory agencies to address these limitations to guarantee sustainability and progress in the probiotic industry and improve long-term public health and development.

Altered gut microbiota in the early stage of acute pancreatitis were related to the occurrence of acute respiratory distress syndrome

Background

Acute respiratory distress syndrome (ARDS) is the most common cause of organ failure in acute pancreatitis (AP) patients, which associated with high mortality. Specific changes in the gut microbiota have been shown to influence progression of acute pancreatitis. We aimed to determine whether early alterations in the gut microbiota is related to and could predict ARDS occurrence in AP patients.

Methods

In this study, we performed 16S rRNA sequencing analysis in 65 AP patients and 20 healthy volunteers. The AP patients were further divided into two groups: 26 AP-ARDS patients and 39 AP-nonARDS patients based on ARDS occurrence during hospitalization.

Results

Our results showed that the AP-ARDS patients exhibited specific changes in gut microbiota composition and function as compared to subjects of AP-nonARDS group. Higher abundances of Proteobacteria phylum, Enterobacteriaceae family, Escherichia-Shigella genus, and Klebsiella pneumoniae, but lower abundances of Bifidobacterium genus were found in AP-ARDS group compared with AP-nonARDS groups. Random forest modelling analysis revealed that the Escherichia-shigella genus was effective to distinguish AP-ARDS from AP-nonARDS, which could predict ARDS occurrence in AP patients.

Conclusions

Our study revealed that alterations of gut microbiota in AP patients on admission were associated with ARDS occurrence after hospitalization, indicating a potential predictive and pathogenic role of gut microbiota in the development of ARDS in AP patients.

Endotipsitis in an Immunocompetent Patient With Lactobacillus Bacteremia

Transjugular intrahepatic portosystemic shunt (TIPS) is a procedure commonly performed to decompress portal venous pressure since the early 1990s. Endotipsitis, which refers to persistent bacteremia caused by endovascular infection of the TIPS stent, is a rare but serious complication of this procedure. Very few cases of endotipsitis have been reported worldwide. We report the case of an immunocompetent patient diagnosed with endotipsitis, an atypical risk factor for Lactobacillus infection. This case report adds to the literature on underreported complications of TIPS, highlighting an urgent need for introducing clinical practice guidelines regarding the definition, diagnosis, and treatment of endotipsitis.

Questioning the fetal microbiome illustrates pitfalls of low-biomass microbial studies

Whether the human fetus and the prenatal intrauterine environment (amniotic fluid and placenta) are stably colonized by microbial communities in a healthy pregnancy remains a subject of debate. Here we evaluate recent studies that characterized microbial populations in human fetuses from the perspectives of reproductive biology, microbial ecology, bioinformatics, immunology, clinical microbiology and gnotobiology, and assess possible mechanisms by which the fetus might interact with microorganisms. Our analysis indicates that the detected microbial signals are likely the result of contamination during the clinical procedures to obtain fetal samples or during DNA extraction and DNA sequencing. Furthermore, the existence of live and replicating microbial populations in healthy fetal tissues is not compatible with fundamental concepts of immunology, clinical microbiology and the derivation of germ-free mammals. These conclusions are important to our understanding of human immune development and illustrate common pitfalls in the microbial analyses of many other low-biomass environments. The pursuit of a fetal microbiome serves as a cautionary example of the challenges of sequence-based microbiome studies when biomass is low or absent, and emphasizes the need for a trans-disciplinary approach that goes beyond contamination controls by also incorporating biological, ecological and mechanistic concepts.

Analysis of the blood bacterial composition of patients with acute coronary syndrome and chronic coronary syndrome

Emerging evidence revealed that the blood microbiota plays a role in several non-communicable diseases, including cardiovascular disease. However, the role of circulating microbes in atherosclerosis remains understudied. To test this hypothesis, we performed this study to investigate the microbial profile in the blood of Chines atherosclerosis volunteers. A total of seventy Acute Coronary Syndrome patients, seventy Chronic Coronary Syndrome patients, and seventy healthy individuals were examined using high-throughput Illumina Novaseq targeting the V3-V4 regions of the 16S rRNA gene. The relationship between atherosclerosis and blood microbiome, clinical variables, and their functional pathways were also investigated. Our study observed significantly higher alpha diversity indices (Chao1, p = 0.001, and Shannon, p = 0.004) in the acute coronary syndrome group compared with chronic coronary syndrome and healthy group, although a significantly lower alpha diversity was observed in the chronic coronary syndrome compared to acute coronary syndrome and healthy group. Beta diversity based on principal coordinate analysis demonstrated a major separation among the three groups. In addition, using linear discriminant analysis, a significant distinct taxon such as Actinobacteria _ phylum, and Staphylococcus_ genus in the healthy group; Firmicutes_ phylum, and Lactobacillus_ genus in the chronic coronary syndrome group, and Proteobacteria and Acidobacteriota _ phyla in acute coronary syndrome group were observed among three groups. Clusters of Orthologous Genes grouped and Kyoto Encyclopedia of Genes and Genomes pathways suggested a significant variation among all groups (p < 0.05). The blood microbiota analysis provides potential biomarkers for the detection of coronary syndromes in this population.

A, Bhardwaj S, Yadav NK, Patel A, Patel A. Gut Microbiota Interventions for the Management of Obesity: A Literature Review

The gut microbiota (GM) has been recognized as an important factor in the development of metabolic diseases such as obesity; it has been reported that the composition of the GM differs in obese and lean subjects, suggesting that microbiota dysbiosis can contribute to changes in body weight. Dysbiosis occurs due to an imbalance in the composition of gut bacteria, changes in the metabolic process, or changes in the distribution of microbiota within the gut. Dysbiosis can change the functioning of the intestinal barrier and the gut-associated lymphoid tissues (GALT). Microbial manipulation may help with preventing or treating weight gain and associated comorbidities. Approaches to this may range from dietary manipulation, which is suitable to treat the individual’s microflora, to probiotics, prebiotics, synbiotics, and fecal microbiota transplant (FMT).

Bacteraemia Caused by Probiotic Strains of Lacticaseibacillus rhamnosus—Case Studies Highlighting the Need for Careful Thought before Using Microbes for Health Benefits

Lactic acid bacteria belonging to Lactobacillus spp. and Lacticaseibacillus spp. are a natural part of fermented milk and other food products, probiotic supplements and human microbiota. They mainly belong to mucosal microflora, especially oral, vaginal and intestinal. Lacticaseibacillus spp. strains included in probiotics are generally characterised as safe microorganisms, and the species are concerned bacteria with very low pathogenic potential. However, infections caused by Lactobacillus spp. and Lacticaseibacillus spp., including bacteraemia and endocarditis, occur occasionally. The aim of the study was to present two cases of bacteraemia due to Lacticaseibacillus rhamnosus associated with the use of a probiotic product. It afflicted patients in intensive care units. The investigation was preliminarily based on clinical and microbiological recognition of the cases. The initial observation was laboratory confirmed with the application of pulsed-field gel electrophoresis (PFGE) results. Identical PFGE patterns were obtained for the evaluated strains and the strains derived from a commercially available probiotic that was administered to those patients. The increasing number of studies describing opportunistic infections due to probiotic strains of Lacticaseibacillus spp. should result in verifying the safety of probiotic formulations used in immunocompromised patients and forming detailed guidelines for the use of probiotics among patients from several risk groups.

Electroacupuncture ameliorates peptic ulcer disease in association with gastroduodenal microbiota modulation in mice

Peptic ulcer disease (PUD) is a common disease and frequently encountered in the clinic. Accumulating evidence suggests that PUD is associated with the gastrointestinal microbiota. Electroacupuncture (EA) is an improved version of acupuncture, which can improve the clinical effect by increasing the stimulation and delivering appropriate electrical pulses to needles. This method has been widely used in the treatment of peptic ulcer disease. However, its effect on gastrointestinal microbiota remains unclear. Therefore, in the present study, the ameliorative effect of EA was evaluated on the gastroduodenal mucosa, and the regulatory effect of the gastroduodenal microbiota was assessed in PUD mice. A total of 48 male Kun Ming mice were randomly divided into the following groups: normal control group (NC), PUD model group (PUD), Shousanli group (LI10), and Zusanli group (ST36) (n=12). The mice in groups LI10 and ST36 were treated with EA at LI10 and ST36, respectively. This intervention was continued for 7 days. Subsequently, we evaluated the morphological changes in the gastric and duodenal mucosa, and specific indices were measured, including the contents of serum dopamine (DA), the trefoil factor (TFF), and the vasoactive intestinal peptide (VIP). In addition, the gastric and duodenal microbiota were assessed via 16S ribosomal DNA sequencing. The results indicated that EA at LI10 or ST36 significantly reduced the injury of the gastroduodenal mucosa in PUD mice. The gastric microbial community structure of the groups LI10 and ST36 was similar to that of the NC group following comparison with the microbial community structure of the PUD model group. Moreover, the abundance of Firmicutes in the stomach was decreased, whereas that of Bacteroidetes was increased, and the abundance of Firmicutes in the duodenum was decreased. Furthermore, the microbial diversity and richness of the gastric microbiota in group LI10 were also significantly increased, and the serum dopamine and trefoil factor levels in group ST36 were significantly increased. Therefore, it is suggested that EA ameliorating PUD is in association with improving the levels of DA and TFF and regulating the relative abundances of Firmicutes and Bacteroidetes in the gastric microbiota.

Microbiota profiling on itchy scalp with undetermined origin

Scalp pruritus is a common skin problem that remains therapeutic challenge. The relationships between the dysbiosis of microbiota and skin diseases have caught attention recently. However, there are few reports about microbiota on itchy scalp. This study investigated scalp microbial characteristics of subjects with mild scalp pruritus of undetermined origin and preliminarily screened physiological factors and bacteria potentially related to pruritus. The pruritus severity of 17 qualified females was evaluated by Visual Analogue Scale (VAS). Microbiota collection was done at both itchy (n = 20) and non-itchy sites (n = 27) at occiput and crown of the same subject and Illumina sequencing was performed at the V3-V4 hypervariable regions of 16S rRNA. The corresponding sebum content, hydration, pH, trans-epidermal water loss, erythema index and porphyrin numbers were also measured by skin tester. We identified 3044 amplicon sequence variants from 821 genera. The itchy and non-itchy sites had different microbiota structures (p = 0.045, by multivariate analysis of variance), while there were large inter- and intra-individual variations. Both sites had Staphylococcus, Cutibacterium and Lawsonella as predominant genera, which were not significantly related to pruritus. The use of three genera Lactobacillus, Morganella and Pseudomonas, could well distinguish non-itchy from itchy groups, whereas different composition patterns existed inside each group. Our investigation indicated that though the bacterial community structure on itchy scalp was individual specific, there was difference between itchy and non-itchy sites. The study provides new insights into microbiota profiling on itchy scalp, which will help microbiota-targeted therapeutic experiment or products design for scalp pruritus.

Lactobacillus rhamnosus sepsis, endocarditis and septic emboli in a patient with ulcerative colitis taking probiotics

A man in his 60s presented to the emergency room with fever and fatigue after a 2.5-month course of corticosteroids. His medical history was significant for bioprosthetic aortic valve replacement and moderately severe ulcerative colitis treated with balsalazide and daily lactobacillus-containing probiotics. Initial investigations revealed Lactobacillus rhamnosus bacteraemia without complication. Four days after hospital discharge, the patient experienced acute-onset right-sided paraesthesia and lower-limb paresis. On return to the emergency room, MRI of the brain demonstrated innumerable ring-enhancing lesions with haemorrhagic transformation. Transoesophageal echocardiogram revealed a small mobile density on the bioprosthetic aortic valve, raising the suspicion for L. rhamnosus infective endocarditis with secondary septic emboli to the brain. The patient was subsequently treated with intravenous gentamycin and ampicillin, with transition to indefinite oral amoxicillin suppressive therapy. The current case highlights the potential risk of lactobacilli translocation in an immunosuppressed patient with ulcerative colitis taking probiotics.

Brain Abscess Due to Lactobacillus Fermentum in an Uncontrolled Diabetic

Brain abscesses are collections of infectious fluid within the brain parenchyma, with mortality ranging from 15% to 31%. They can result from direct inoculation or via hematogenous spread. Streptococcus and staphylococcus species and Gram-negative bacilli are common bacteria responsible for brain abscesses. In immunocompromised patients, such as those with organ transplants or HIV, brain abscesses can be caused by fungi, mycobacteria, or parasites. Lactobacillus is a very rare cause of brain abscess and has only been observed in a few case reports. We report a case of a woman with uncontrolled diabetes who presented with altered mental status and was found to have a brain abscess secondary to Lactobacillus fermentum.

Infection prevention requirements for the medical care of immunosuppressed patients: recommendations of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) at the Robert Koch Institute

In Germany, guidelines for hygiene in hospitals are given in form of recommendations by the Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention, "KRINKO"). The KRINKO and its voluntary work are legitimized by the mandate according to § 23 of the Infection Protection Act (Infektionsschutzgesetz, "IfSG"). The original German version of this document was published in February 2021 and has now been made available to the international professional public in English. The guideline provides recommendations on infection prevention and control for immunocompromised individuals in health care facilities. This recommendation addresses not only measures related to direct medical care of immunocompromised patients, but also management aspects such as surveillance, screening, antibiotic stewardship, and technical/structural aspects such as patient rooms, air quality, and special measures during renovations.

Effect of Electroacupuncture at Zusanli (ST36) on Intestinal Microbiota in Rats With Chronic Atrophic Gastritis

Background: Electroacupuncture is a common treatment for chronic atrophic gastritis (CAG) in China. We aimed to determine the effects of electroacupuncture at zusanli (ST36) on intestinal microbiota in CAG rats.

Methods: In total, 42 SD rats were randomly divided into normal (NC, 10 rats) and model (MG, 32 rats) groups. Rats in the MG group were established as CAG disease models. After that, the rats in the MG group were randomly divided into CAG (10 rats), electroacupuncture (EA, 10 rats), and Vitacoenzyme (Vit, 10 rats) groups. Rats in the NC and CAG groups were subjected to a 30-min/d confinement for 4 weeks. Rats in the EA group were given electroacupuncture at zusanli for 30 min/d for 4 weeks. Rats in the Vit group were given Vitacoenzyme solution 10 ml/(kg d) for 4 weeks. Histopathological changes in the gastric mucosa were observed with hematoxylin and eosin staining, and the gene expression level of p53, Bcl-2, and c-myc was determined using the qPCR method. The 16S rDNA sequencing technique was used to determine structural changes and relative abundance expression of intestinal flora.

Results: Compared with the NC group, gastric mucosal pathology in the CAG group revealed significant inflammatory infiltration, and the gastric mucosal lesions in the electroacupuncture group were improved remarkably; the expression of p53 and c-myc genes in the CAG group increased (p < 0.05), while the expression of Bcl-2 genes decreased (p < 0.05) in the EA group, that of p53 and c-myc genes decreased (p < 0.05), and that of Bcl-2 genes increased (p < 0.05). The abundance of bacteria such as Lactobacillus, Desulfobacterota, and Bacteroides pectinophilus group in the CAG group increased (p < 0.05), while that of bacteria such as Gastranaerophilales, Romboutsia, and Blautia decreased (p < 0.05). The relative abundance of Desulfobacterota and Helicobacter in the EA group decreased (p < 0.05), while that of probiotic bacteria such as Oscillospirales, Romboutsia, and Christensenellaceae increased (p < 0.05).

Conclusion: Electroacupuncture at zusanli can promote the repair of pathological damage to the gastric mucosa in rats with CAG, and the mechanism might relate to the reduction in the relative abundance of harmful bacteria, increase in the relative abundance of intestinal probiotics, and regulation of the intestinal microbiota.

Use of Limosilactobacillus reuteri DSM 17938 in paediatric gastrointestinal disorders: an updated review

Strains of lactobacilli are the most widely used probiotics and can be found in a large variety of food products and food supplements throughout the world. In this study, the evidence on Limosilactobacillus reuteri DSM 17938 (LR DSM 17938) has been reviewed. This species secretes reuterin and other substances singularly or in microvesicles, inhibiting pathogen growth and interacting with the intestinal microbiota and mucosa, restoring homeostasis. The use of LR DSM 17938 has been exploited in several pathological conditions. Preclinical research has shown that this probiotic can ameliorate dysbiosis and, by interacting with intestinal mucosal cells, can raise the pain threshold and promote gastrointestinal motility. These aspects are amongst the significant components in functional gastrointestinal disorders, such as colic and regurgitation in infants, functional abdominal pain and functional constipation in children and adolescents. This strain can decrease the duration of acute diarrhoea and hospitalization for acute gastroenteritis but does not seem to prevent nosocomial diarrhoea and antibiotic-associated diarrhoea. Because of its ability to survive in the gastric environment, it has been tested in Helicobacter pylori infection, showing a significant decrease of antibiotic-associated side effects and a tendency to increase the eradication rate. Finally, all these studies have shown the excellent safety of LR DSM 17938 even at higher dosages. In conclusion data from various clinical trials here reviewed can guide the clinician to find the correct dose, frequency of administration, and therapy duration.

A Comparative Genomic and Safety Assessment of Six Lactiplantibacillus plantarum subsp. argentoratensis Strains Isolated from Spontaneously Fermented Greek Wheat Sourdoughs for Potential Biotechnological Application

The comparative genome analysis of six Lactiplantibacillus plantarum subsp. argentoratensis strains previously isolated from spontaneously fermented Greek wheat sourdoughs is presented. Genomic attributes related to food safety have been studied according to the European Food Safety Authority (EFSA) suggestions for the use of lactic acid bacteria (LAB) in the production of foods. Bioinformatic analysis revealed a complete set of genes for maltose, sucrose, glucose, and fructose fermentation; conversion of fructose to mannitol; folate and riboflavin biosynthesis; acetoin production; conversion of citrate to oxaloacetate; and the ability to produce antimicrobial compounds (plantaricins). Pathogenic factors were absent but some antibiotic resistance genes were detected. CRISPR and cas genes were present as well as various mobile genetic elements (MGEs) such as plasmids, prophages, and insertion sequences. The production of biogenic amines by these strains was not possible due to the absence of key genes in their genome except lysine decarboxylase associated with cadaverine; however, potential degradation of these substances was identified due to the presence of a blue copper oxidase precursor and a multicopper oxidase protein family. Finally, comparative genomics and pan-genome analysis showed genetic differences between the strains (e.g., variable pln locus), and it facilitated the identification of various phenotypic and probiotic-related properties.

Virulence of Lactobacillus spp. misidentified as Enterococcus faecalis from children's carious dentine

Objective: This study aimed to search for Enterococcus faecalis in children's deep carious dentine and characterize their virulence traits.Material and Methods: Eight isolates from 15 carious molars identified by 16S rDNA species-specific PCR as E. faecalis were included. These eight isolates were subject to identification by MALDI-TOF and characterized regarding: (i) bacterial aggregation and biofilm formation on polystyrene and glass, with/without saliva, as single or dual-species (associated to Streptococcus mutans); (ii) environmental pH measurement before and after 24 h incubation; (iii) acidogenicity; (iv) gelatinase production; (v) macrophage adherence; and (vi) toxicity towards Caenorhabditis elegans. Statistical analyses were performed using two-way ANOVA/Tukey or Fisher's exact tests.Results: All isolates initially identified as E. faecalis by PCR were correctly identified as Lactobacillus by MALDI-TOF, being designated as Lactobacillus misidentified as Enterococcus (LME). These isolates produced biofilm in the presence of saliva and in the dual-species assays. Bacterial aggregation was only observed in the dual-species model. After 24 h, environmental pH dropped from 7.5 to 4.5 for seven of eight isolates, and to 4.0 in all dual-species models. LME isolates were acidogenic, none of them produced gelatinase or adhered to macrophages, but all presented toxicity towards C. elegans.Conclusions: No E. faecalis were identified in the children's caries lesions. All LME isolates presented important virulence traits, including biofilm formation and high acidogenicity, which cause enamel demineralization, that might increase the risk of dental caries in children carrying LME. Thus, the correct identification and in-depth virulence characterization of microorganisms isolated from dental caries are important to understand the dynamics of this disease.

Investigation and comparison of the effects of two probiotic bacteria, and in reducing mutans streptococci levels in the saliva of children

Background

Probiotic organisms Lactobacillus reuteri UBLRU-87 and Bifidobacterium bifidum UBBB-55 were proven to be acting against the caries causing organisms.

Aims

This study aims to evaluate the influence of Lactobacillusreuteri, Bifidobacterium bifidum and their blend on Mutans streptococci count in the saliva of children, and also to appraise the sustainability of their action.

Materials and Methods

A randomized, double-blind and placebo-controlled study with 60 subjects (15 in each group) in 6-14 years of age group. The children consumed curd containing Bifidobacterium bifidum (UBBB 55, MTCC 5398) and Lactobacillus reuteri (UBLRu 87, MTCC 5403), and their blend once daily for 14 days. The control group received curd with no Probiotic in it. The saliva samples were collected just before the curd (T0) administration to establish baseline levels of mutans streptococci and after a day of the final consumption of the curd (T14). The follow-up samples at 21 days (T21) and 28 days (T28) after the baseline were also collected to know the sustainability of action probiotics on mutans streptococci if any.

Results

Statistically significant reduction of mutans streptococci is observed in the group administered with Lactobacillus reuteri and the effect lasted up to a minimum of 21 days. Mixed cultures are seemed to be not effective against the oral microorganisms.

Conclusions

The probiotic organism Lactobacillus reuteri in Indian curd is effective on salivary mutans streptococci, and the effect was sustained for some period after the administration.

Lactobacillus jensenii mitral valve endocarditis: Case report, literature review and new perspectives

Lactobacillus is a facultative anaerobic Gram-positive rod usually found in the normal microbiota of the gastrointestinal and genitourinary tract. Frequently dismissed as a contaminant, it is implicated in several diseases. We describe a rare case of endocarditis caused by Lactobacillus jensenii in an immunocompetent 40 year-old male patient, with a history of mitral valve repair. He presented complaining of asthenia and his laboratory results showed a moderate increase in inflammatory markers. A trans-thoracic echocardiography confirmed a vegetation on the posterior leaflet of the mitral valve, with associated severe mitral insufficiency. Blood cultures revealed the significant growth of L. jensenii. The patient developed an acute abdomen with intestinal ischemia and occlusion of the superior mesenteric artery, requiring urgent surgical laparotomy. A cerebral MRI showed multiple minor emboli in the frontal and left parietal cortex. The patient consequently underwent surgery to have his mitral valve replaced with a mechanical valve. L. jensenii was isolated in culture from the mitral valve and from a mesenteric artery thrombus. After one week of combined amoxicillin and gentamicin therapy, ampicillin alone was continued for a total of six weeks and the patient could be discharged in a good general condition. Only five cases of L. jensenii are described in literature, and they mainly affect immunocompromised hosts. In our case, a long delay between the start of symptoms and the full onset of the disease was observed. tolerance of Lactobacilli to penicillin is a key determinant of therapy choice.

Probiotics: Should All Patients Take Them?

The usefulness of probiotics in the treatment as well as prevention of many infections and disorders has been confirmed by previous clinical studies. They can protect not only against gastrointestinal diseases such as diarrhea or enteritis but they have proven efficacy against pneumonia, urogenital infection, depression/anxiety, cancer metastasis, obesity, and others. However, it should be mentioned that not all clinical trials have shown improvement of health in patients undergoing probiotic treatment, and very rarely have even reported that probiotic strains may be the causative agents of opportunistic infections. Studies have documented cases of sepsis/bacteremia, endocarditis, liver abscess, pneumonia, and fungemia caused by probiotic strains, mainly in high-risk groups. This review summarizes the cases of infections caused by probiotic strains and the potential hazard associated with the supplementation of probiotics in seriously ill and hospitalized patients.

Strategies for the treatment of colorectal cancer caused by gut microbiota

Colorectal cancer (CRC), also named as colon and rectal or bowel cancer, is one of the leading neoplasia diagnosed in the world. Genetic sequencing studies of microorganisms from the intestinal microbiota of patients with CRC revealed that changes in its composition occur with the development of the disease, which can play a fundamental role in its development, being mediated by the production of metabolites and toxins that damage enterocytes. Some microorganisms are frequently reported in the literature as the main agents of this process, such as the bacteria Fusobacterium nucleatum, Escherichia coli and Bacteroides fragilis. Thus, understanding the mechanisms and function of each microorganism in CRC is essential for the development of treatment tools that focus on the gut microbiota. This review verifies current research aimed at evaluating the microorganisms present in the microbiota that can influence the development of CRC, as well as possible forms of treatment that can prevent the initiation and/or spread of this disease. Due to the incidence of CRC, alternatives have been launched considering factors beyond those already known in the disease development, such as diet, fecal microbiota transplantation, use of probiotics and antibiotics, which have been widely studied for this purpose. However, despite being promising, the studies that focus on the development of new therapeutic approaches targeting the microorganisms that cause CRC still need to be improved and better developed, involving new techniques to elucidate the effectiveness and safety of these new methods.

Clinical anaerobic infections in an Indian tertiary care hospital: A two-year retrospective study

OBJECTIVE

To study the spectrum of anaerobic infections and the frequency of clinically relevant anaerobes in various infections in a tertiary care hospital in North India.

METHOD

In this two-year (2018-2019) retrospective study, a total of 22,177 samples were processed both anaerobically and aerobically. The samples included blood, pus, body fluids, necrotic tissues, abscess, peritoneal fluids, and other specimens of conditions predisposing to anaerobic infections. The recovered bacterial isolates were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).

RESULT

Of the 22,177 samples processed anaerobically, 1094 showed significant anaerobic growth yielding 1464 anaerobes. Bacteroides fragilis (12.7%) and Peptoniphilus harei (12.2%) were the most predominant anaerobes, whereas Escherichia coli (32.6%) and Staphylococcus aureus (13.2%) were the most frequently recovered facultative anaerobes in polymicrobial growth. Both aerobic and anaerobic data were available for 673/1094 samples, of which 68% represented a polymicrobial etiology and 32% as monomicrobial. Of the cases where complete clinical information was available (504/1094), the majority of the anaerobes were recovered from the skin and soft tissue infections (36.3%) and intra-abdominal infections (17.1%). The clinical specimen most frequently growing anaerobes was abscess (29.1%), followed by diabetic foot ulcers (14.1%).

CONCLUSION

The study documents the frequency of clinically significant anaerobic bacteria in various infections, and their associations with aerobes in polymicrobial growth. The present study may aid us in devising better therapeutic strategies against both aerobes and anaerobes in anaerobic infections, which is often empirical. Besides, the data can update clinicians with the changing patterns of anaerobic infections, which remains a neglected concern.

Crosstalk between gut microbiota and sepsis

Sepsis is an overwhelming inflammatory response to microbial infection. Sepsis management remains a clinical challenge. The role of the gut microbiome in sepsis has gained some attention. Recent evidence has demonstrated that gut microbiota regulate host physiological homeostasis mediators, including the immune system, gut barrier function and disease susceptibility pathways. Therefore, maintenance or restoration of microbiota and metabolite composition might be a therapeutic or prophylactic target against critical illness. Fecal microbiota transplantation and supplementation of probiotics are microbiota-based treatment methods that are somewhat limited in terms of evidence-based efficacy. This review focuses on the importance of the crosstalk between the gastrointestinal ecosystem and sepsis to highlight novel microbiota-targeted therapies to improve the outcomes of sepsis treatment.

The Challenge of ICIs Resistance in Solid Tumours: Could Microbiota and Its Diversity Be Our Secret Weapon?

The human microbiota and its functional interaction with the human body were recently returned to the spotlight of the scientific community. In light of the extensive implementation of newer and increasingly precise genome sequencing technologies, bioinformatics, and culturomic, we now have an extraordinary ability to study the microorganisms that live within the human body. Most of the recent studies only focused on the interaction between the intestinal microbiota and one other factor. Considering the complexity of gut microbiota and its role in the pathogenesis of numerous cancers, our aim was to investigate how microbiota is affected by intestinal microenvironment and how microenvironment alterations may influence the response to immune checkpoint inhibitors (ICIs). In this context, we show how diet is emerging as a fundamental determinant of microbiota’s community structure and function. Particularly, we describe the role of certain dietary factors, as well as the use of probiotics, prebiotics, postbiotics, and antibiotics in modifying the human microbiota. The modulation of gut microbiota may be a secret weapon to potentiate the efficacy of immunotherapies. In addition, this review sheds new light on the possibility of administering fecal microbiota transplantation to modulate the gut microbiota in cancer treatment. These concepts and how these findings can be translated into the therapeutic response to cancer immunotherapies will be presented.

Aggrandizement of fermented cucumber through the action of autochthonous probiotic cum starter strains of Lactiplantibacillus plantarum and Pediococcus pentosaceus

Purpose

Cucumber fermentation is traditionally done using lactic acid bacteria. The involvement of probiotic cultures in food fermentation guarantees enhanced organoleptic properties and protects food from spoilage.

Methods

Autochthonous lactic acid bacteria were isolated from spontaneously fermented cucumber and identified to species level. Only strains adjudged as safe for human consumption were examined for their technological and functional characteristics. Strain efficiency was based on maintaining high numbers of viable cells during simulated GIT conditions and fermentation, significant antioxidant activity, EPS production, nitrite degradation, and antimicrobial ability against Gram-positive and Gram-negative foodborne pathogens.

Result

Two strains, Lactiplantibacillus plantarum NPL 1258 and Pediococcus pentosaceus NPL 1264, showing a suite of promising functional and technological attributes, were selected as a mixed-species starter for carrying out a controlled lactic acid fermentations of a native cucumber variety. This consortium showed a faster lactic acid-based acidification with more viable cells, at 4% NaCl and 0.2% inulin (w/v) relative to its constituent strains when tested individually. Sensory evaluation rated the lactofermented cucumber acceptable based on texture, taste, aroma, and aftertaste.

Conclusion

The results suggest that the autochthonous LAB starter cultures can shorten the fermentation cycle and reduce pathogenic organism’ population, thus improving the shelf life and quality of fermented cucumber. The development of these new industrial starters would increase the competitiveness of production and open the country’s frontiers in the fermented vegetable market.

Infected pancreatic necrosis and retroperitoneal abscess associated with Lactobacillus paracasei

Infected pancreatic necrosis is a postpancreatitis complication that is mainly caused by Enterobacteriaceae and Enterococci. Here, we have reported a very rare case of Lactobacillus paracasei bacteraemia associated with infected pancreatic necrosis and retroperitoneal abscess. In addition to the diagnosis of diabetic ketoacidosis, blood test results revealed a high inflammatory status. CT of the abdomen revealed pancreatic walled-off necrosis. Blood culture and aspiration fluid culture revealed positivity for L. paracasei, leading to the diagnosis of infected pancreatic necrosis. The abscess had spread in the retroperitoneal space later. The patient recovered after receiving antibiotic treatment and endoscopic and percutaneous drainage. L. paracasei can cause invasive infection, including infected pancreatic necrosis and retroperitoneal abscess, which requires aggressive therapy.

Probiotic Bacterial Application in Pediatric Critical Illness as Coadjuvants of Therapy

The use of probiotics in critically ill adult and children patients has been growing exponentially over the last 20 years. Numerous factors in pediatriac intensive care unit (PICU) patients may contribute to intestinal dysbiosis, which subsequently promotes the pathobiota's growth. Currently, lactobacillus and bifidobacterium species are mainly used to prevent the development of systemic diseases due to the subverted microbiome, followed by streptococcus, enterococcus, propionibacterium, bacillus and Escherichia coli, Lactobacillus rhamnosus GG, and Lactobacillus reuteri DSM 17938. The aim of this article is to review the scientific literature for further confirmation of the importance of the usage of probiotics in intensive care unit (ICU) patients, especially in the pediatric population. A progressive increase in nosocomial infections, especially nosocomial bloodstream infections, has been observed over the last 30 years. The World Health Organization (WHO) reported that the incidence of nosocomial infections in PICUs was still high and ranged between 5% and 10%. Petrof et al. was one of the first to demonstrate the efficacy of probiotics for preventing systemic diseases in ICU patients. Recently, however, the use of probiotics with different lactobacillus spp. has been shown to cause a decrease of pro-inflammatory cytokines and an increase in anti-inflammatory cytokines. In addition, in some studies, the use of probiotics, in particular the mix of Lactobacillus and Bifidobacterium reduces the incidence of ventilator-associated pneumonia (VAP) in PICU patients requiring mechanical ventilation. In abdominal infections, there is no doubt at all about the usefulness of using Lactobacillus spp probiotics, which help to treat ICU-acquired diarrhoea episodes as well as in positive blood culture for candida spp. Despite the importance of using probiotics being supported by various studies, their use is not yet part of the standard protocols to which all doctors must adhere. In the meantime, while waiting for protocols to be drawn up as soon as possible for use in PICUs, routine use could certainly stimulate the intestine's immune defences. Though it is still too early to say, they could be considered the drugs of the future.

Topical Delivery of Lactobacillus Culture Supernatant Increases Survival and Wound Resolution in Traumatic Acinetobacter baumannii Infections

Species of Lactobacillus have been proposed as potential candidates for treating wound infections due to their ability to lower pH, decrease inflammation, and release antimicrobial compounds. This study investigated the impact of lactobacilli (Lactobacillus acidophilus ATCC 4356, Lactobacillus casei ATCC 393, Lactobacillus reuteri ATCC 23272) secreted products on wound pathogens in vitro and in a murine wound infection model. Evaluation of 1-5 day lactobacilli conditioned media (CM) revealed maximal inhibition against wound pathogens using the 5-day CM. The minimum inhibitory concentration (MIC) of 5-day Lactobacillus CMs was tested by diluting CM in Mueller-Hinton (MH) broth from 0 to 25% and was found to be 12.5% for A. baumannii. Concentrating the CM to 10× with a 3 kDa centrifuge filter decreased the CM MIC to 6.25-12.5% for A. baumannii planktonic cells. Minimal impact of 5-day CMs was observed against bacterial biofilms. No toxicity was observed when these Lactobacillus CMs were injected into Galleria melonella waxworms. For the murine A. baumannii wound infection studies, improved survival was observed following topical treatment with L. acidophilus ATCC 4356 or L. reuteri ATCC 23272, while L. reuteri ATCC 23272 treatment alone improved wound resolution. Overall, this study suggests that the topical application of certain Lactobacillus species byproducts could be effective against gram-negative multi-drug resistant (MDR) wound pathogens, such as A. baumannii.

Antimicrobial Susceptibility of Lactic Acid Bacteria Strains of Potential Use as Feed Additives - The Basic Safety and Usefulness Criterion

The spread of resistance to antibiotics is a major health concern worldwide due to the increasing rate of isolation of multidrug resistant pathogens hampering the treatment of infections. The food chain has been recognized as one of the key routes of antibiotic resistant bacteria transmission between animals and humans. Considering that lactic acid bacteria (LAB) could act as a reservoir of transferable antibiotic resistance genes, LAB strains intended to be used as feed additives should be monitored for their safety. Sixty-five LAB strains which might be potentially used as probiotic feed additives or silage inoculants, were assessed for susceptibility to eight clinically relevant antimicrobials by a minimum inhibitory concentration determination. Among antimicrobial resistant strains, a prevalence of selected genes associated with the acquired resistance was investigated. Nineteen LAB strains displayed phenotypic resistance to one antibiotic, and 15 strains were resistant to more than one of the tested antibiotics. The resistance to aminoglycosides and tetracyclines were the most prevalent and were found in 37 and 26% of the studied strains, respectively. Phenotypic resistance to other antimicrobials was found in single strains. Determinants related to resistance phenotypes were detected in 15 strains as follows, the aph(3″)-IIIa gene in 9 strains, the lnu(A) gene in three strains, the str(A)-str(B), erm(B), msr(C), and tet(M) genes in two strains and the tet(K) gene in one strain. The nucleotide sequences of the detected genes revealed homology to the sequences of the transmissible resistance genes found in lactic acid bacteria as well as pathogenic bacteria. Our study highlights that LAB may be a reservoir of antimicrobial resistance determinants, thus, the first and key step in considering the usefulness of LAB strains as feed additives should be an assessment of their antibiotic resistance. This safety criterion should always precede more complex studies, such as an assessment of adaptability of a strain or its beneficial effect on a host. These results would help in the selection of the best LAB strains for use as feed additives. Importantly, presented data can be useful for revising the current microbiological cut-off values within the genus Lactobacillus and Pediococcus.

Lactobacillus gasseri liver abscess and bacteremia: a case report

BACKGROUND

Lactobacillus is a genus of Gram-positive non-spore-forming rods usually found in the microbiota of the oral cavity, gastrointestinal tract, and female genitourinary tract. Also, they are commonly used in the food industry as supplements and probiotics. Lactobacilli are normally considered non-pathogenic to the human body, however, under certain circumstances such as immunosuppression, they can cause severe infections, with only a few cases of bacteremia, infective endocarditis, pneumonia, meningitis, and intra-abdominal infections reported. Among these presentations, a pyogenic liver abscess is rather rare.

CASE PRESENTATION

We describe the case of a 59-year-old man with a history of diabetes mellitus and multiple abdominal surgeries with the latest being in 2014 presenting with bacteremia and multiple large pyogenic liver abscesses due to Lactobacillus gasseri, which did not appear to be related to the use of probiotics or immunosuppression.

CONCLUSIONS

Given the high prevalence of diabetes mellitus and the increased use of probiotics, it is expected that in the future we will see an increase in infections caused by Lactobacilli. Medical management with antibiotics and percutaneous drainage were successful strategies for the treatment of this unusual case of pyogenic liver abscesses and bacteremia caused by Lactobacillus gasseri.

Microbiota and Metabolites as Factors Influencing Blood Pressure Regulation

The study of microbes has rapidly expanded in recent years due to a surge in our understanding that humans host a plethora of commensal microbes, which reside in their bodies and depending upon their composition, contribute to either normal physiology or pathophysiology. This article provides a general foundation for learning about host-commensal microbial interactions as an emerging area of research. The article is divided into two sections. The first section is dedicated to introducing commensal microbiota and its known effects on the host. The second section is on metabolites, which are biochemicals that the host and the microbes use for bi-directional communication with each other. Together, the sections review what is known about how microbes interact with the host to impact cardiovascular physiology, especially blood pressure regulation. © 2021 American Physiological Society. Compr Physiol 11:1731-1757, 2021.