Gram-negative Enteric Bacteria Research Articles

A Familiar Outbreak of Monophasic Salmonella serovar Typhimurium (ST34) Involving Three Dogs and Their Owner's Children.

Salmonella is a Gram-negative enteric bacterium responsible for the foodborne and waterborne disease salmonellosis, which is the second most reported bacterial zoonosis in humans. Many animals are potential sources of salmonellosis, including dogs, cats, and other pets. We report the case of an outbreak of salmonellosis in a family in central Italy, affecting two children and involving their three dogs as carriers. One of the children needed medical care and hospitalisation. Isolation and analysis of stool samples from the sibling and the animals present in the house were carried out. Serotyping allowed the identification of S. enterica subsp. enterica serovar Typhimurium in its monophasic variant for all the isolates. The results of whole-genome sequencing confirmed that the strains were tightly related. The minimum inhibitory concentration (MIC) test documented the resistance to ampicillin, sulfamethoxazole, and tetracycline. The origin of the zoonotic outbreak could not be assessed; however, the case study showed a clear passage of the pathogen between the human and non-human members of the family. The possibility of a transmission from a dog to a human suggests the need for further studies on the potential ways of transmission of salmonellosis through standard and alternative feed.

Modified nutrient medium for isolation and identification of non-fermenting bacteria

The relevance of this study is due to the need for laboratory monitoring of the circulation of gram-negative non-fermenting bacteria that have a high etiological significance in the occurrence of nosocomial infections, as well as the complexity of differentiating these bacteria on simple nutrient media from representatives of enterobacteria and between individual representatives of gram-negative non-fermenting bacteria.
 The purpose of this study was to design a differential diagnostic medium containing domestic ingredients.
 Materials and methods. The growth efficiency of test strains on comparable nutrient media, their cultural and morphological characteristics were determined.
 Results. The modified culture medium makes it possible to distinguish test strains of gram-negative non-fermenting bacteria from test strains of other bacteria (gram-negative enterobacteria, Staphylococcus), and between these strains by the color of the colonies and growth patterns. This feature gives the opportunity to apply modified medium for the differentiation of non-fermentative bacteria from fermenting ones and, simultaneously, for the primary differentiation of different representatives of non-fermenting bacteria by changing the color of the medium and different color of colonies.

S3525 A Rare Case of Campylobacter and Strongyloides stercoralis Co-infection in an Immunocompetent Host

Introduction: Strongyloides stercoralis is a parasitic nematode mainly seen in immigrants and military personnel from endemic areas. Most cases in immunocompetent hosts are incidental findings or present with mild gastrointestinal (GI), respiratory or dermal symptoms. Co-infection with organisms like Campylobacter coupled with anatomical abnormalities such as a hiatal hernia can produce similar symptoms delaying diagnosis and treatment. Case Description/Methods: A 75 year-old-woman presented with persistent watery diarrhea, nausea, dyspepsia, and non-bloody and non-bilious vomiting over the past five days. She also had an unintentional weight loss of 50 pounds over the past three months. She denied any recent travel, rashes, or fevers/chills. On presentation, she was hemodynamically stable with generalized abdominal tenderness on physical exam. CT of the abdomen revealed a moderately-sized hiatal hernia. Serologies were significant for normocytic anemia, thrombocytosis, and eosinophilia (white blood cell count 5300, eosinophils 6.6%). Stool studies were positive for Campylobacter and she was started on azithromycin. She initially felt better and was subsequently discharged on azithromycin. She then presented three days later with complaints of nausea, and bloody emesis. Upper endoscopy with biopsy was done which showed a Los Angeles grade D reflux esophagitis and duodenitis. Histological evaluation revealed S. stercoralis in the duodenal mucosa (Figure 1). Initial ova and parasite cultures from a week ago further confirmed the diagnosis. She was then started on an extended course of ivermectin with a resolution of her symptoms and was discharged home. Discussion: Campylobacter is an enteric gram-negative bacterium that also affects the GI tract and can mimic S. stercoralis infection clinically. Co-infection with this organism occurs due to its similar mode of transmission, however, there have only been a few cases documented in literature. Diagnosis is made by stool testing and serology, however, stool tests are only positive in 50-60% of cases. Eosinophilia may or may not be present. Clinicians should be aware that despite having underlying structural abnormalities such as a hiatal hernia, an EGD with biopsy is warranted to rule out infectious etiologies especially in the presence of eosinophilia as seen above. Early diagnosis and treatment are essential in preventing disseminated disease, especially in immunocompromised patients.Figure 1.: Hematoxylin and Eosin stain of the duodenum revealing acute duodenitis with associated Strongyloides stercoralis in the intestinal crypts and lumen.

34086 Rapid response of truncal acne with oral sarecycline

Truncal acne affects 60-70% of acne patients and larger surface areas than facial acne. Topical treatment application becomes more difficult. Oral sarecycline, a narrow-spectrum, third-generation tetracycline-class antibiotic, is FDA-approved for moderate-to-severe acne vulgaris in patients aged 9 and older. Sarecycline’s potent anti-inflammatory activity, activity against Cutibacterium acnes and clinically relevant Gram-positive bacteria, but reduced activity against enteric Gram-negative bacteria, may contribute to its favorable safety and tolerability profile.

Acute renal injury from thrombotic microangiopathy associated with enteritis in New Zealand white rabbits.

Over a 3-y period, 12 adult New Zealand white (NZW) rabbits were presented for postmortem examination following variably long periods of inappetence and soft-to-liquid stool production. Postmortem findings included serosanguineous fluid in abdominal and thoracic cavities, dark-red-to-white renal foci, reddened intestinal serosa, and pulmonary edema. Microscopically, mesangial changes and thrombi were observed in renal glomeruli, and mild-to-severe enteritis was observed. These findings resemble hemolytic uremic syndrome, which typically follows enterocolitis associated with Shiga toxin (Stx)-producing Escherichia coli infection. In our case series, various gram-negative bacteria, most commonly E. coli, were isolated from the intestinal tracts; however, Stx production was not demonstrated. Evidence of Encephalitozoon cuniculi infection, a common cause of renal disease in rabbits, was also not found. Our cases suggest that gram-negative enteric bacteria should be included in the differential diagnosis of renal disease in NZW rabbits, especially in cases with an accompanying clinical history of gastrointestinal disorder.

Klebsiella Pneumoniae Infections: A Future Threat to Global Health?

Klebsiella pneumoniae is an enteric capsulated Gram-negative bacterium that is a major supergerm. Traditionally recognized as a relevant pathogen in hospital environment, K. pneumoniae strains-mainly the multidrug-resistant ones-are currently related to mild and severe infections in the community. Pediatrics invasive diseases are especially of great concern [1].

Community Associated Methicillin-Resistant Staphylococcus Aureus Causing Acute Urinary Tract Infection and Epididymo-Orchitis: A Case Report

Acute epididymitis is most commonly infectious in etiology, usually secondary to a urinary tract infection (UTI) or a sexually transmitted infections (like gonorrhea and chlamydia). Enteric gram-negative bacteria (like Escherichia coli) and coagulase-negative Staphylococcus saprophyticus are the most frequently encountered organisms associated with UTIs. Staphylococcus aureus, especially methicillin-resistant Staphylococcus aureus (MRSA), is an uncommon pathogen when considering community associated acute UTI and acute epididymitis. We present an unusual case of a 28-years-old immunocompetent male, who presented with a left scrotal swelling and was found to have acute epididymo-orchitis due to an acute MRSA UTI.

Corrigendum: Determination and molecular analysis of antibiotic resistance in Gram-negative enteric bacteria isolated from Pelophylax sp. in the Eastern Black Sea Region.

"Corrigendum: Determination and molecular analysis of antibiotic resistance in Gram-negative enteric bacteria isolated from Pelophylax sp. in the Eastern Black Sea Region" published on 07 Feb 2022 by Akadémiai Kiadó.

Prevalence of E. coli as a causative agent of urinary tract infections and its drug susceptibility patterns among pregnant mothers seeking medicare at Kisii teaching and referral hospital, Kenya

Background: E-coli, a gram-negative entero-bacteria has been associated with urinary tract infections (UTIs) and antimicrobial resistances in human and animals. This study aimed at establishing the prevalence of E. coli among other bacteria causing UTIs in pregnant women seeking Medicare at Kisii teaching and referral hospital (KTRH), Kenya and to establish the drug susceptibility patterns of the isolated E. coli. Setting-The project was done at Kisii teaching and referral hospital, Kenya.Methods: This hospital based experimental and cross-sectional study conducted in 3 months between March and June 2020 involved 119 pregnant women whose urine samples were cultured on Cysteine Leucine Electrolyte deficiency media (CLED) at 370C overnight and sub-cultured on Mueller Hinton media. Bacterial identification was done by Gram stain and biochemical characterization using indole, methyl-red, Voges-Proskaur and citrate tests while susceptibility tests were conducted by Kirby Bauer disc diffusion technique.Results: Out of the 119 urine samples, E. coli 28 (23.5%) was the second most prevalent after S. aureus 40 (33.6%). Others included S. epidermidis 27 (22.7%), and Proteus spp. 9 (7.6%). All E. coli isolates, 28 (100%) demonstrated resistance to sulfamethoxazole followed by amoxyclave 24 (85.75%), and ceftriaxone 20 (71.42%). They were least resistant to gentamycin 4 (14. 28%) and ofloxacin 6 (21.42%).Conclusions: E. coli which largely exists as a commensal can cause UTIs and could be possessing antimicrobial resistant genes responsible for treatment failure. This demands for new effective therapeutic alternatives and more research on bacterial drug resistant.

Exploiting Caenorhabditis elegans to discover human gut microbiota-mediated intervention strategies in protein conformational diseases.

Exploiting Caenorhabditis elegans to discover human gut microbiota-mediated intervention strategies in protein conformational diseases.

Clinical characteristics and outcome of primary brain abscess: a retrospective analysis

BackgroundPatients with primary brain abscess often present with atypical symptoms, and the outcome varies. We investigated the demographic, laboratory, and neuroimaging features of patients with brain abscess at our hospital and identified factors associated with their outcomes.MethodsWe retrospectively collected the data of patients diagnosed with primary brain abscess at our hospital between January 2011 and December 2020. Their clinical characteristics, predisposing factors, laboratory and neuroimaging findings, treatment, and outcome were analyzed.ResultsOf the 57 patients diagnosed with primary abscess, 51 (89.47%) were older than 40 years, and 42 (73.68%) were male. Only eight patients (14.04%) showed the classical triad of headache, fever, and focal neurological deficit. Fifteen patients (26.31%) had comorbidities, of which diabetes mellitus was the most common. Positive intracranial purulent material cultures were obtained in 46.15% of the patients, and gram-negative enteric bacteria were found in 33.33% of them, with Klebsiella pneumoniae being the most frequently observed. Surgical treatment, most commonly in the form of stereotactic drainage, was received by 54.39% of the patients. Good outcomes were achieved in 75.44% of the patients. Multivariate logistic regression analysis showed that patients with headaches were more likely to have a poor outcome (odds ratio 6.010, 95% confidence interval 1.114–32.407, p = 0.037).ConclusionsMale patients and those older than 40 years were more susceptible to brain abscess than female patients and those younger than 40 years, respectively. Only a few patients showed the classical triad of clinical symptoms. Diabetes mellitus was the most common comorbidity. Positive intracranial specimens’ culture results were uncommon, with gram-negative enteric bacteria, especially Klebsiella pneumoniae, being the main organisms found. Most patients had a good outcome, and the presence of headache may influence the outcome.

Antibacterial Activity of Combination of Ethanol Extract of Pepermine Leaves (Mentha piperita L.) and Amikacin Against Klebsiella pneumonia, Staphylococcus aureus, and Escherichia coli

Peppermint leaves have been known to have antibacterial and antifungal activity. Amikacin is a semisynthetic derivative of kanamycin which is active against both Gram-positive and Gram-negative enteric bacteria. The combination of plant extracts with antibiotics is one way or alternative to overcome bacterial resistance to antibiotics. The purpose of this study was to determine the combined effect of the ethanolic extract of peppermint (Mentha piperita L.) and amikacin against Klebsiella pneumonia, Staphylococcus aureus, and Escherichia coli as well as the compounds contained in the ethanolic extract of peppermint (Mentha piperita L.) leaves. Antibacterial activity was tested using the disk diffusion method (Kirby Bauer) and the phytochemical screening test using the tube test method. The concentration of peppermint leaf ethanol extract for the combination test was 200 mg/mL and 400 mg/mL, for the concentration of amikacin used was 5 mg/mL with three comparisons made, namely 25:75, 50:50, and 75:25. The results showed a synergistic effect with the largest inhibition zone diameter at a ratio of 25:75 at a concentration of 200 mg/mL, which was 36.25±2.5 mm on Klebsiella pneumonia bacteria. While at a concentration of 400 mg/mL the diameter of the largest inhibition zone was 40±1.63 mm in Klebsiella pneumoniae bacteria with a ratio of 75:25. The results of statistical tests using the t-test showed a significance value of 0.000 0.05 so that there was a significant difference in the administration of each concentration to the resulting inhibition zone. The results of the phytochemical screening test contained alkaloids, phenolic compounds, flavonoids, tannins.

Closing the Brief Case: “Great Pretender”—Disseminated Blastomycosis in Western North Carolina

1. Which of the following stains are not used to visualize Blastomyces spp.? a. Gomori methenamine silver (GMS) stain b. Periodic acid-Schiff (PAS) stain c. Calcofluor white with potassium hydroxide d. Ziehl-Neelsen stainAnswer: d. Gomori methenamine silver and periodic acid-Schiff are used to visualize Blastomyces during histopathology. Calcofluor white with potassium hydroxide is used to stain direct specimens. Ziehl-Neelsen is used for the identification of mycobacteria and not used for the identification of endemic fungi. 2. How is Blastomyces species infection usually acquired? a. Through cutaneous direct inoculation b. Inhalation of conidia c. Bloodstream spread after trauma d. Animal biteAnswer: b. Although direct inoculation is possible, the most common way of acquiring blastomycosis is through inhalation of the conidia. Blastomycosis after an animal bite has been described but is not common. 3. Which culture medium is preferred for recovery of Blastomyces spp.? a. Buffered charcoal yeast extract (BCYE) b. Brain heart infusion with sheep’s blood and gentamicin (BHISG) c. MacConkey agar d. Chocolate agarAnswer: b. Blastomyces spp. grow on BHISG, BCYE, and chocolate agar. However, BHISG is preferred due to the enriched growth of Blastomyces spp. and the inhibition of bacterial growth, which is particularly important for nonsterile specimens. The BCYE plate is sometimes included with fungal cultures to allow for the isolation of Nocardia and other aerobic actinomycetes, but any bacterial growth outcompetes Blastomyces spp. on this medium. The MacConkey agar is used for the recovery of enteric Gram-negative bacteria in bacterial cultures and does not support the growth of Blastomyces spp.

Determination and molecular analysis of antibiotic resistance in Gram-negative enteric bacteria isolated from Pelophylax sp. in the Eastern Black Sea Region.

The aim of this study was to evaluate the prevalence and types of antimicrobial resistance among Gram-negative enteric bacteria isolated from Pelophylax sp. Fifty-four frogs were collected from six provinces in the Eastern Black Sea Region of Turkey. In the cloacal swab cultures, bacteria from 160 different colonies were identified by biochemical tests, automated systems, and matrix-assisted laser desorption ionisation-time of flight mass spectrometry. The antimicrobial susceptibility tests were performed by the disk diffusion method. The observed drug resistance rate was the highest to ampicillin and cefazolin, while the lowest against ciprofloxacin and tetracycline. In the molecular assays, bla TEM (8 Citrobacter spp.), bla SHV (2 Escherichia coli, 1 Hafnia alvei, and a Serratia liquefaciens), tetA genes (E. coli and Klebsiella spp.) and a class 1 integron without any gene cassette (E. coli) were detected. Among the strains, no plasmid-mediated quinolone resistance [qnrA, qnrB, qnrS, qepA and aac (6 ')-Ib-cr] was found. However, two of three quinolone-resistant Klebsiella strains showed the novel amino acid substitution in the gyrA gene resulting in Ser83Asp and Asp87Glu.The clonality between E. coli isolates was also examined by pulsed-field gel electrophoresis. We consider that multidrug-resistant Gram-negative enteric bacteria in the intestinal microbiota of a cosmopolitan frog species might be a reservoir for antibiotic resistance genes.

Phenotypic and genotypic characterization of plasmid-mediated AmpC beta-lactamases in enteric Gram-negative bacteria from patients with lower respiratory tract infections in a tertiary hospital, southwest Nigeria

Background: AmpC or class C or group 1 beta lactamases are class C cephalosporinases that hydrolyse a wide variety of beta-lactam antibiotics including alpha methoxy beta-lactams (cefoxitin), narrow and broad spectrum cephalosporins. This study was conducted to characterize plasmid-mediated AmpC producing enteric Gram- negative bacteria from patients with lower respiratory tract infections in Obafemi Awolowo University Teaching Hospital Complex (OAUTHC) Ile Ife, Osun State, NigeriaMethodology: A total of 149 patients with clinical features of lower respiratory tract infections (LRTI) were selected by simple random sampling for the study. All Gram-negative isolates recovered from standard microbiological cultures of respiratory specimens of these patients were tested against cefoxitin, third generation cephalosporins (3GCs), and other antibiotics using the disc diffusion AST method, and also screened for production of AmpC beta-lactamases phenotypically by the CLSI method. Plasmid DNA extraction was carried out on twenty-nine cefoxitin-resistant selected isolates using the Kado and Lin method, while genotypic detection of plasmid-mediated AmpC gene was carried out by the polymerase chain reaction (PCR) assay.Results: The results showed that 204 (43.3%) of 471 isolates recovered from the 149 selected patients were resistant to 3GC in the AST assay, among which 121 (59.3%) were resistant to cefoxitin, and 189 of the 471 isolates (40.1%) were AmpC producers. The AmpC producers concurrently showed multiple resistance pattern to other antibiotics tested in this study. Ninety six percent of the 29 selected isolates for plasmid analysis contained plasmids, 45% of which amplified positive on PCR for CMY, 38% for FOX, and 31% for ACC types of AmpC genes.Conclusion: This study showed a high degree of antibiotic resistance among enteric Gram-negative bacteria recovered from patients with LRTIs, as well as high degree of plasmid-encoded AmpC genes responsible for this high antibiotic resistance among the isolates. Proper antibiotic policy and regulation are required to limit the spread of plasmid mediated AmpC β-lactamase producing organisms because they can lead to therapeutic failure in infected patients in the nearest future.
 
 French title: Caractérisation phénotypique et génotypique des bêta-lactamases AmpC à médiation plasmidique dans les bactéries entériques Gram-négatives de patients atteints d'infections des voies respiratoires inférieures dans un hôpital tertiaire, sud-ouest du Nigéria
 Contexte: Les bêta-lactamases AmpC ou de classe C ou de groupe 1 sont des céphalosporinases de classe C qui hydrolysent une grande variété d'antibiotiques bêta-lactamines, y compris les alpha-méthoxy bêta-lactamines (céfoxitine), les céphalosporines à spectre étroit et large. Cette étude a été menée pour caractériser les bactéries à Gram négatif entériques produisant de l'AmpC à médiation plasmidique chez des patients atteints d'infections des voies respiratoires inférieures du complexe hospitalier universitaire d'Obafemi Awolowo (OAUTHC) Ile Ife, État d'Osun, NigériaMéthodologie: Un total de 149 patients présentant des caractéristiques cliniques d'infections des voies respiratoires inférieures (LRTI) ont été sélectionnés par échantillonnage aléatoire simple pour l'étude. Tous les isolats à Gram négatif récupérés à partir de cultures microbiologique standard d'échantillons respiratoires de ces patients ont été testés contre la céfoxitine, les céphalosporines de troisième génération (3GC) et d'autres antibiotiques en utilisant la méthode AST de diffusion sur disque, et également criblés pour la production de bêtalactamases AmpC phénotypiquement par le Méthode CLSI. L'extraction de l'ADN plasmidique a été réalisée sur 29 isolats sélectionnés résistants à la céfoxitine en utilisant la méthode Kado et Lin, tandis que la détection génotypique du gène AmpC à médiation plasmidique a été réalisée par le test de réaction en chaîne par polymérase (PCR).Résultats: Les résultats ont montré que 204 (43,3%) des 471 isolats récupérés des 149 patients sélectionnés étaient résistants à la 3GC dans le test AST, parmi lesquels 121 (59,3%) étaient résistants à la céfoxitine et 189 des 471 isolats (40,1%) étaient des producteurs d'AmpC. Les producteurs d'AmpC ont montré simultanément plusieurs profils de résistance à d'autres antibiotiques testés dans cette étude. Quatre-vingt-seize pour cent des 29 isolats sélectionnés pour l'analyse des plasmides contenaient des plasmides, dont 45% amplifiés positifs par PCR pour CMY, 38% pour FOX et 31% pour les types ACC des gènes AmpC.Conclusion: Cette étude a montré un degré élevé de résistance aux antibiotiques parmi les bactéries entériques Gram-négatives récupérées chez des patients atteints de LRTI, ainsi qu'un degré élevé de gènes AmpC codés par plasmide responsable de cette résistance élevée aux antibiotiques parmi les isolats. Une politique et une réglementation appropriées en matière d'antibiotiques sont nécessaires pour limiter la propagation des organismes producteurs β-lactamase d'AmpC à médiation plasmidique car ils peuvent conduire à un échec thérapeutique chez les patients infectés dans un avenir proche.

Microbiome or Infections: Amyloid-Containing Biofilms as a Trigger for Complex Human Diseases.

The human microbiota is the community of microorganisms that live upon or within their human host. The microbiota consists of various microorganisms including bacteria, fungi, viruses, and archaea; the gut microbiota is comprised mostly of bacteria. Many bacterial species within the gut microbiome grow as biofilms, which are multicellular communities embedded in an extracellular matrix. Studies have shown that the relative abundances of bacterial species, and therefore biofilms and bacterial byproducts, change during progression of a variety of human diseases including gastrointestinal, autoimmune, neurodegenerative, and cancer. Studies have shown the location and proximity of the biofilms within the gastrointestinal tract might impact disease outcome. Gram-negative enteric bacteria secrete the amyloid curli, which makes up as much as 85% of the extracellular matrix of enteric biofilms. Curli mediates cell-cell attachment and attachment to various surfaces including extracellular matrix components such as fibronectin and laminin. Structurally, curli is strikingly similar to pathological and immunomodulatory human amyloids such as amyloid-β, which has been implicated in Alzheimer's disease, α-synuclein, which is involved in Parkinson's disease, and serum amyloid A, which is secreted during the acute phase of inflammation. The immune system recognizes both bacterial amyloid curli and human amyloids utilizing the same receptors, so curli also induces inflammation. Moreover, recent work indicates that curli can participate in the self-assembly process of pathological human amyloids. Curli is found within biofilms of commensal enteric bacteria as well as invasive pathogens; therefore, evidence suggests that curli contributes to complex human diseases. In this review, we summarize the recent findings on how bacterial biofilms containing curli participate in the pathological and immunological processes in gastrointestinal diseases, systemic autoimmune diseases, and neurodegenerative diseases.

Usefulness of the MALDI-TOF MS technology with membrane filter protocol for the rapid identification of microorganisms in perioperative drainage fluids of hepatobiliary pancreatic surgery.

Surgical site infections (SSIs) are significant and frequent perioperative complications, occurring due to the contamination of the surgical site. The late detection of SSIs, especially organ/space SSIs which are the more difficult to treat, often leads to severe complications. An effective method that can identify bacteria with a high accuracy, leading to the early detection of organ/space SSIs, is needed. Ninety-eight drainage fluid samples obtained from 22 patients with hepatobiliary pancreatic disease were analyzed to identify microorganisms using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) with a new membrane filtration protocol and rapid BACpro® pretreatment compared to sole rapid BACpro® pretreatment. The levels of detail of rapid BACpro® pretreatment with or without filtration were also evaluated for the accuracy of bacterial identification. We found that reliable scores for E. coli and E. faecalis were obtained by inoculation with 1.0 × 104 CFU/ml after preparation of the membrane filter with rapid BACpro®, indicating approximately 10-folds more sensitive compared to sole rapid BACpro® pretreatment in drainage fluid specimens. Among 60 bacterial positive colonies in drainage fluid specimens, the MALDI-TOF MS and the membrane filtration with rapid BACpro® identified 53 isolates (88.3%) with a significantly higher accuracy, compared to 25 isolates in the rapid BACpro® pretreatment group (41.7%) (p < 0.001). Among the 78 strains, 14 enteric Gram-negative bacteria (93.0%) and 55 Gram-positive cocci (87.3%) were correctly identified by the membrane filtration with rapid BACpro® with a high reliability. This novel protocol could identify bacterial species within 30 min, at $2-$3 per sample, thus leading to cost and time savings. MALDI-TOF MS with membrane filter and rapid BACpro® is a quick and reliable method for bacterial identification in drainage fluids. The shortened analysis time will enable earlier selection of suitable antibiotics for treatment of organ/space SSIs to improve patients' outcomes.

In Vitro Evaluation of the Effect of Storage at −20°C and Proximal Gastrointestinal Conditions on Viability of Equine Fecal Microbiota Transplant

Fecal microbiota transplant (FMT), a technique used to restore normal intestinal microbial communities, has been successful in treating humans with Clostridioides difficile colitis. Subsequently, FMT is being used in veterinary patients with suspected intestinal dysbiosis. Unfortunately, little data are available regarding best practices for FMT in horses. The objective of this study was to evaluate the effects of storing manure prepared for equine FMT (MP-FMT) at −20°C for up to 4 weeks and passage through a simulated proximal gastrointestinal (GI) tract on the viability of MP-FMT. The results of this study indicate that storage at −20°C for greater than 1 week and exposure to conditions consistent with the proximal GI tract significantly decreased viability of the microbial population, with gram-negative enteric bacteria most significantly impacted. This preliminary evaluation indicates that further work is necessary to determine best practices to preserve the viability MP-FMT in horses.

Peculiarities of antimicrobial therapy of viral and bacterial pneumonia in patients with coronavirus disease

Background. The coronavirus pandemic (COVID-19) currently dominates all health problems. Adequate initial antimicrobial therapy of viral and bacterial pneumonia in patients with COVID-19 requires compliance with a number of features that are fundamentally important in the context of global growth of resistance of pathogenic flora to antimicrobial drugs.&#x0D; Objective. To describe the features of antimicrobial therapy of viral and bacterial pneumonia in patients with COVID-19.&#x0D; Materials and methods. Analysis of literature data on this issue.&#x0D; Results and discussion. Severe coronavirus infection triggers an avalanche-like generalized inflammatory response with rapid vascular endothelial damage. Lungs is the main target organ of this aggression. A significant part of all endothelial cells of the body is concentrated in the lungs, so the cascade of multiorgan disorders begins with them. Liver, intestines, kidneys and muscles are the organs that suffer from extrapulmonary manifestations of COVID-19. SARS-CoV-2 сoronavirus also has neurotropism, so it is able to affect the nervous system, both central and peripheral. The pathogenesis, diagnosis and treatment of COVID-19 should be considered in terms of the approaches used in sepsis. This disease is characterized by the following laboratory changes: increased content of C-reactive protein, leukocytosis or leukopenia, lymphopenia, neutrophilia, increased activity of alanine and aspartate aminotransferases, creatine phosphokinase, lactate dehydrogenase, bilirubin and creatinine concentrations. However, sufficiently sensitive and specific markers for the diagnosis and prediction of COVID-19 are currently lacking. Until the results of the polymerase chain reaction for SARS-CoV-2 and, consequently, the confirmation of COVID-19, are absent, all patients with severe pneumonia and acute respiratory distress syndrome should be treated as patients with acute severe community-acquired pneumonia. Empirical combination antibiotic therapy should be started immediately. Patients over 60 years of age with pre-existing comorbidities need special attention. The spectrum of microbial flora in such patients includes Streptococcus pneumoniae, Chlamydophila pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, gram-negative enterobacteria. This must be taken into account when choosing an antibiotic. In presence of intracellular pathogens, fluoroquinolones have an advantage over macrolides and tetracyclines. Due to the growing resistance of hospital flora to macrolides and the high risk of resistance to them in outpatient flora, the initial use of fluoroquinolones is one of the main trends in modern antibiotic therapy. The advantages of levofloxacin are the possibility of administration in short courses (750 mg once a day for 5 days), a wide activity spectrum, the ability to overcome the basic mechanisms of resistance, a good safety profile. Intravenous administration of levofloxacin is not inferior to the effectiveness of the combination of β-lactams and macrolides and can be completed by transferring the patient to oral treatment. For the treatment of patients at risk of Pseudomonas aeruginosa infection, combination therapy is prescribed – antipseudomonad cephalosporins of III-IV generation in combination with aminoglycosides, ciprofloxacin or levofloxacin. Alternatively, carbapenems are prescribed in combination with aminoglycosides (tobramycin – Braxon, “Yuria-Pharm”) or fluoroquinolones (levofloxacin – Leflocin, “Yuria-Pharm”). When methicillin-resistant Staphylococcus aureus is detected, the use of linezolid (Linelid, “Yuria-Pharm”) is advisable. Antibiotic therapy is often accompanied by fungal infections. In severe cases of the latter, as well as in pulmonary aspergillosis voriconazole (Vizealot, “Yuria-Pharm”) is prescribed.&#x0D; Conclusions. 1. Severe coronavirus infection triggers an avalanche-like generalized inflammatory reaction with rapid damage to the vascular endothelium. 2. In the presence of intracellular pathogens, fluoroquinolones have an advantage over macrolides and tetracyclines. 3. The initial use of fluoroquinolones is one of the main trends in modern antibiotic therapy. 4. In the detection of methicillin-resistant Staphylococcus aureus, it is advisable to use linezolid. 5. In severe fungal infections and pulmonary aspergillosis, voriconazole is prescribed.

Involvement of GcvB small RNA in intrinsic resistance to multiple aminoglycoside antibiotics in Escherichia coli.

Deleting the gene for small RNA GcvB in Escherichia coli was found to increase the sensitivity to several aminoglycoside antibiotics, such as neomycin, streptomycin, kanamycin, kasugamycin and spectinomycin, at low concentrations. GcvB, conserved in gram-negative enteric bacteria, is known to negatively control the expression of many genes for amino acid incorporation systems, especially the periplasmic ABC-transporter proteins. Deletions of several amino acid transporter genes in ΔgcvB cells decreased the antibiotic sensitivity to the wild-type level, suggesting that those genes are involved in uptake of aminoglycosides into the cell. Since GcvB is constitutively synthesized in growing cells, repressing synthesis of amino acid transporters, it contributes to the intrinsic resistance to several aminoglycoside antibiotics.