Stuartii Research Articles

Differential Contribution of Hydrogen Metabolism to Proteus mirabilis Fitness during Single-Species and Polymicrobial Catheterized Urinary Tract Infection.

Proteus mirabilis is a common uropathogen and a leading cause of catheter-associated urinary tract infections (CAUTIs), which are often polymicrobial. Through a genome-wide screen, we previously identified two [NiFe] hydrogenases as candidate fitness factors for P. mirabilis CAUTI: a Hyb-type Group 1c H2-uptake hydrogenase and a Hyf-type Group 4a H2-producing hydrogenase. In this study, we disrupted one gene of each system (hyfE and hybC) and also generated a double mutant to examine the contribution of flexible H2 metabolism to P. mirabilis growth and fitness in vitro and during experimental CAUTI. Since P. mirabilis is typically present as part of a polymicrobial community in the urinary tract, we also examined the impact of two common co-colonization partners, Providencia stuartii and Enterococcus faecalis, on the expression and contribution of each hydrogenase to fitness. Our data demonstrate that neither system alone is critical for P. mirabilis growth in vitro or fitness during experimental CAUTI. However, perturbation of flexible H2 metabolism in the ∆hybC∆hyfE double mutant decreased P. mirabilis fitness in vitro and during infection. The Hyf system alone contributed to the generation of proton motive force and swarming motility, but only during anaerobic conditions. Unexpectedly, both systems contributed to benzyl viologen reduction in TYET medium, and disruption of either system increased expression of the other. We further demonstrate that polymicrobial interactions with P. stuartii and E. faecalis alter the expression of Hyb and Hyf in vitro as well as the contribution of each system to P. mirabilis fitness during CAUTI.

Genomic characterization of New Delhi metallo-beta-lactamase-producing species of Morganellaceae, Yersiniaceae, and Enterobacteriaceae (other than Klebsiella) from Brazil over 2013-2022.

Over the last decade, New Delhi metallo-beta-lactamase (NDM) carbapenemase has silently spread in Brazil. In this study, we analyzed a large collection of Enterobacterales other than Klebsiella spp. received in our reference laboratory between 2013 and 2022. A total of 32 clinical isolates displaying different pulsed-field gel electrophoresis profiles, and represented by 11 species in the families Enterobacteriaceae (Citrobacter freundii, Citrobacter portucalensis, Enterobacter hormaechei, and Escherichia coli), Morganellaceae (Morganella morganii, Proteus mirabilis, Proteus vulgaris, Providencia rettgeri, Providencia stuartii, and Raoultella ornithinolytica), and Yersiniaceae (Serratia marcescens) had their whole genomes sequenced and further analyzed. Antimicrobial susceptibility was determined by disk diffusion, except for polymyxin B, assessed by broth microdilution. The blaNDM-1 allele was predominant (n = 29), but blaNDM-5 was identified in an E. coli specimen with a novel ST, and the blaNDM-7 allele was found in E. hormaechei ST45 and E. coli ST1049. Polymyxin was active against all but one Enterobacteriaceae isolate: an mcr-1-producing E. coli presenting minimal inhibitory concentration (4 mg/L). Isolates producing extended-spectrum β-lactamases were common: cefotaximase from Munich (CTX-M)-15 (n = 10), CTX-M-2 (n = 4), and CTX-M-8 (n = 3) were detected, and the mcr-1-producing E. coli was found to co-produce both CTX-M-8 and CTX-M-55 β-lactamases. The mcr-9 gene was found in 5/8 E. hormaechei isolates, distributed in four different sequence types, all of them presenting susceptibility to polymyxin. This study showed that NDM-producing Enterobacterales other than Klebsiella are already spread in Brazil, in diversified species, and cocarrying important resistance genes. Prompt detection and effective implementation of measures to prevent further spread are mandatory for mitigating the dissemination of NDM carbapenemase in hospital settings and preserving the already limited antimicrobial therapy options.

Epidemiology and characterization of Providencia stuartii isolated from hospitalized patients in southern Brazil: a possible emerging pathogen.

This study aimed to characterize the virulence factors and antimicrobial resistance of Providencia stuartii , an opportunistic pathogen that causes human infections. We examined 45 isolates of P. stuartii both genotypically and phenotypically by studying their adherence to HeLa cells, biofilm formation, cytotoxicity and antimicrobial resistance, and analysed their genomes for putative virulence and resistance genes. This study found that most isolates possessed multiple virulence genes, including fimA, mrkA, fptA, iutA, ireA and hlyA, and were cytotoxic to Vero cells. All the isolates were resistant to amoxicillin plus clavulanic acid, levofloxacin and sulfamethoxazole plus trimethoprim, and most were resistant to ceftriaxone and cefepime. All isolates harboured extended-spectrum beta-lactamase coding genes such as bla CTX-M-2 and 23/45(51.11 %) of them also harboured bla CTX-M-9. The gene KPC-2 (carbapenemase) was detected in 8/45(17.77 %) isolates. This study also found clonality among the isolates, indicating the possible spread of the pathogen among patients at the hospital. These results have significant clinical and epidemiological implications and emphasize the importance of a continued understanding of the virulence and antimicrobial resistance of this pathogen for the prevention and treatment of future infections.

The Prevalence of Extended Spectrum Beta Lactamase Producing Citrrobacter Freundii and Pprovidencia Stuartii from Medical Laboratories in Parts of Lagos State, Nigeria

Citrobacter freundii and Providencia stuartii are members of the family Enterobacteriaceae which are emerging as important Extended Spectrum Beta Lactamase (ESBL) producing pathogens. This study was aimed to determine the prevalence of ESBL and carbapenemase production in C. freundii and P. stuartii. from laboratories in the northwest of Lagos. A total of 134 isolates were obtained from laboratories. Isolate identification, antibiotics susceptibility testing, and phenotypic detection of ESBL production were done using standardized procedures. Multiplex polymerase chain reaction (PCR) was performed on ESBL producing isolates to detect blaTEM, blaSHV, blaCTX-M, blaKPC, blaVIM, blaIMP and blaOXA. Out of 134 isolates 15 (11.2%) were Citrobacter freundii and only 2 (1.5%) were of the Providencia genus both of which were Providencia rettgeri and Providencia stuartii. A total of 9 (60%) tested positive for the production of Extended Spectrum Beta Lactamase (ESBL) enzyme while only Providencia stuartii of the Providencia genus also produced ESBL. Also, 8 (47%) of the initial Citrobacter and Providencia isolates produced carbapenemase Molecular characterization showed that 4 (44.4%) and 1 (100%) of the Citrobacter freundii and Providencia stuartii isolates respectively, displayed the presence of CTX-M gene while 2 (20%) of all ESBL producing isolates also possessed SHV gene including 1 (11.1%) of ESBL producing Citrobacter freundii and 1 (100%) of ESBL producing Providencia stuartii. Antibiotic susceptibility testing showed that Citrobacter freundii displayed the highest resistance to Ceftazidime and Cefotaxime at 71.4% and the least resistance to Amoxicillin-Clavulanate at 28.6%. Providencia stuartii also displayed absolute resistance (100%), to cefotaxime and ciprofloxacin and absolute susceptibility (100%) to Ceftazidime. Also, Citrobacter freundii showed the same resistance patterns with 57.1% resistance to Gentamicin, Cefuroxime and Ceftriaxone antibiotics while Providencia stuartii showed varied resistance patterns with absolute resistance (100%), absolute susceptibility (100%) and absolute resistance (100%) to Gentamicin, Cefuroxime and Ceftriaxone antibiotics respectively. In conclusion, the Multiple Antibiotic Resistance Index values of both bacterial genera showed that 70.6% were from High-Risk sources indicating that the majority of bacteria analysed were from environments where they have been subjected to a high burden of antibiotic exposure.

Microbiological analysis of nosocomial pneumonia at Tanta University Chest Hospital

BackgroundHospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) represent a major health problem among hospitalized patients leading to consequent morbidity and mortality specially after Covid-19 era and spread of multidrug-resistance organisms)MDRO) in hospitals.AimThis study aimed to analyze the commonest microorganisms responsible for HAP and VAP at Tanta University Chest Hospital.MethodsThis prospective observational study was done at Chest Department, Faculty of Medicine, started from June 2022 to February 2023. Fifty HAP patients’ sputum samples and 50 VAP patients (25 endotracheal aspirates and 25 bronchoalveolar lavages) were included. All collected samples were submitted to standard microbiological tests at Microbiology Department, Tanta Faculty of Medicine.ResultsA total number of 50 HAP and 50 VAP cases were included. Microbial isolates were relatively the same in both groups, where Klebsiella pneumoniae was the predominant isolates (56) followed by Staphylococcus aureus (25), Escherichia coli (14), Pseudomonas aeruginosa (13), Acinetobacter baumannii (5), Streptococcus pneumoniae (4), Enterococci (3), Stenotrophomonas maltophilia (2), Citrobacter freundii (2), Streptococcus pyogenes (2), Providencia stuartii (1), and 7 isolates of Candida. Antimicrobial susceptibility showed predominance of drug-resistance organisms in VAP (78%) versus HAP (28%), P-value: < 0.001. Klebsiella pneumonia showed higher rates of resistance (37 out of 56 isolates, P-value = 0.020). Four out of 5 Acinetobacter baumannii isolates were multidrug resistant, and 2 isolates of Stenotrophomonas maltophilia were polydrug resistant. Multivariate logistic regression analysis showed that intravenous antibiotic administration within last 3 months was associated with risk for MDR-HAP, while univariate regression analysis showed that intravenous antibiotic administration within the last 3 months was the strongest predictor for MDR-VAP. A higher mortality rate was recorded in VAP group (66%), versus (14%) in HAP group (P-value: < 0.001).ConclusionMicrobial isolates were relatively the same in both HAP and VAP, but VAP showed significant predominance of drug-resistant organisms. The most significant predictor for risk of MDRO infection in HAP and VAP was intravenous antibiotic administration within last 3 months; so, raising attention towards antibiotic choice may improve the outcome. Finally, VAP was associated with higher mortality compared to HAP.

Antibacterial potential and modes of action of methanol extracts of flowers and leaves of Vernonia glabra (Steetz) Vatke (Asteraceae) against multidrug-resistant Gram-negative bacteria overexpressing efflux pumps

Background: Bacterial infections caused by multidrug-resistant (MDR) Gram-negative bacteria remain a public health problem and have contributed to a reduction in the range of antibiotics available for antibiotic therapy. The search for new antibacterial substances is becoming increasingly important, and plants represent an important reservoir of therapeutic molecules. In the present study, the antibacterial activity and modes of action of Vernonia glabra against Gram-negative and multi-resistant bacteria were evaluated. Methods: The antibacterial activity of Vernonia glabra extracts was assessed using the broth microdilution method, and the effects of the flower extract on bacterial growth kinetics and on the H+-proton pump/ATPase of Providencia stuartii ATCC29916 were carried out using standard experimental protocols; qualitative reference methods were used to identify the secondary metabolites present in the extracts. Results: Phytochemical screening of Vernonia glabra flower and leaf extracts revealed the presence of alkaloids, phenols, flavonoids, tannins, triterpenes, saponins and anthocyanins. The flower and leaf extracts showed antibacterial activity of 100% and 93.33% respectively against the bacteria tested. With minimum inhibitory concentrations (MICs) ranging from 32 µg/mL to 2048 µg/mL, the flower extract showed excellent activity against Escherichia coli AG100 and Providencia stuartii ATCC29916 with a MIC of 32 µg/mL, while the leaf extract showed good activity against Klebsiella pneumoniae ATCC11296 and Providencia stuartii PS2636 with a MIC of 256 µg/mL. The flower extract inhibited the growth of Providencia stuartii ATCC22916 at the exponential phase and inhibited its H+ proton pumps/ATPase. In the presence of the efflux pump inhibitor, phenylalanine-arginine β-naphthylamide (PAβN), the activity of the leaf extract was enhanced on 90.90% of the bacteria tested. With activity enhancement factors ranging from 2 to 128, both extracts potentiated the activity of antibiotics (imipenem, ampicillin, levofloxacin, tetracycline, vancomycin, ceftriaxone, ciprofloxacin, and doxycycline) against at least 70% of the bacteria tested. Conclusion: The results obtained in the present work show that Vernonia glabra is a source of antibacterial molecules that can be used against MDR Gram-negative bacteria. Keywords: Antibacterial; Asteraceae; efflux pumps; modes of action; multidrug resistance; Vernonia glabra.

A moderately active crude methanol extract from the whole plant of Kalanchoe crenata (Andrews) Haw. (Crassulaceae) strongly potentiated the effect of antibiotics against multidrug-resistant Gram-negative bacteria

Background: Resistant bacteria develop a high level of resistance to multiple drugs, limiting treatment options and increasing morbidity and mortality. This work was planned to evaluate the antibacterial potential of the methanol extract from the whole plant of Kalanchoe crenata (KCW) against multidrug-resistant (MDR) Gram-negative bacteria. Methods: The minimal inhibitory concentrations (MIC) and the minimal bactericidal concentrations (MBC) of KCW alone, in the presence of an efflux pump inhibitor (EPI) phenylalanine-arginine β-naphthylamide (PAβN), or in the presence of antibiotics were assessed using the broth microdilution method combined with the rapid para-iodonitrotetrazolium chloride (INT) colorimetric technique. Results: KCW displayed weak antibacterial activities with MIC values ranging from 128 to 1024 μg/mL against 10 of the 15 tested bacterial strains. Moderate antibacterial activities with MIC values ranging from 128-625 μg/mL were recorded against some strains belonging to Klebsiella pneumoniae, Escherichia coli, and Providencia stuartii. PAβN does not significantly enhance the activity KCW. At MIC/2, KCW potentiated the activity of doxycycline (DOX), levofloxacin (LEV), imipenem (IMI), ciprofloxacin (CIP), ceftriaxone (CRO), and tetracycline (TET) against at least 80% of the MDR bacterial strains tested. Conclusion: The present study demonstrated that KCW is a moderately active antibacterial agent, but a good efflux pump inhibitor that could potentiate the activity of antibiotics against MDR bacteria over-expressing active efflux pumps. Keywords: Antibacterial; antibiotic-potentiation; Crassulaceae; efflux pumps; Kalanchoe crenata; multidrug resistance.

Plasmid-Borne Mobile Colistin Resistant Gene (Mcr-1) Detection and Multidrug Resistant Bacteria Isolated from Some Abattoir Environments in Benin City, Edo State, Nigeria

Antibiotics resistance is an increasing public health challenge globally, and very recently, global attention has focused on colistin, which is termed “last resort antibiotics”. This study was aimed at investigating the prevalence of plasmid-borne mobile colistin resistant and multidrug resistant bacteria from 6 major abattoirs located in Benin City, Edo State, Nigeria. Two hundred and eighty-eight samples from fresh water, wastewater, utensils, and handlers were obtained over a 6-months period. Mean mesophilic aerobic bacteria (MAB) and thermotolerant coliform bacteria (TCB) were determined by pour plate method, while the indoor air of the abattoirs was sampled using passive sedimentation technique. Bacterial isolates were identified by morphological, biochemical and 16S rRNA analysis. Phenotypic detection of colistin-resistance as well as multi-drug resistant profile of all isolates was done by the modified Kirky Bauer method. The presence and/or absence of colistin-resistance gene (mcr-1 to mcr-8) were investigated by polymerase chain reaction. The MAB ranged from 0.3 ± 0.0 cfu/m3 in indoor air from both Holy Ghost B and Bob Izua abattoir to 2.6 ± 0.3 cfu/ml in wash water from Holy Ghost A abattoir, while the TCB ranged from 0.0 ± 0.0 cfu/ml in wastewater from Lawal and Sons abattoir to 0.6 ± 0.1 cfu/ml in wash water from Osazee abattoir. A total of 149 bacterial isolates, belonging to 6 different species (Pseudomonas aeruginosa PA01, Enterobacter ludwigii EN-119, Providencia stuartii PRV00010, Klebsiella quasipneumoniae strain KqPF26, Enterococcus saccharolyticus ATCC 43076 and Provincia rettgeri strain AR_0082) were obtained with the majority (&gt;90%) being multidrug resistant. Seven (4.7%) of the isolates were phenotypically resistant to colistin, while only 3 harbored the mcr-1 gene. This result shows that plasmid-borne colistinresistant and multidrug resistant bacteria are prevalent in abattoir environment located in Benin City, Edo State, Nigeria. This is an indication that abattoir facilities could be a source of human exposure to colistin resistant bacteria, and efforts must be made at reducing the high dependence of antibiotics in farm animals.

Isolation and antibacterial activity of anomanol B and other secondary metabolites from the stem bark of Anonidium mannii (Annonaceae)

A new Lanosta-7,9(11),22-trien-3,15,20-triol named Anomanol B 1, together with five known compounds: manniindole 2, arborinine 3, polycarpol 4, 8,9-dimethoxyphenanthridin-6(5H)-one 5 and 3-O-β-D-glucopyranosyl-β-sitosterol 6 were isolated from the stem bark extract of Anonidium mannii by routine chromatography techniques. 8,9-dimethoxyphenanthridin-6(5H)-one 5, was reported from natural origin for the first time. The structures of the compounds were established by comprehensive elucidation of spectroscopic data and by comparison with literature data. Evaluation of the isolates on Gram-negative bacteria such as Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Providencia stuartii, and Pseudomonas aeruginosa showed that, compound 1 had weak antibacterial activity with minimal inhibitory concentrations (MIC) varying from 128 to 256 µg/mL. Compounds 3, 5, and 6 exhibited moderate to weak activity with MIC of 32 to 128 µg/mL and 64 to 256 µg/mL compared to the reference drug chloramphenicol which inhibited the growth of all studied bacteria with MIC values of 16 to 64 µg/mL.

Genome-Based Retrospective Analysis of a Providencia stuartii Outbreak in Rome, Italy: Broad Spectrum IncC Plasmids Spread the NDM Carbapenemase within the Hospital.

Providencia stuartii is a member of the Morganellaceae family, notorious for its intrinsic resistance to several antibiotics, including last-resort drugs such as colistin and tigecycline. Between February and March 2022, a four-patient outbreak sustained by P. stuartii occurred in a hospital in Rome. Phenotypic analyses defined these strains as eXtensively Drug-Resistant (XDR). Whole-genome sequencing was performed on the representative P. stuartii strains and resulted in fully closed genomes and plasmids. The genomes were highly related phylogenetically and encoded various virulence factors, including fimbrial clusters. The XDR phenotype was primarily driven by the presence of the blaNDM-1 metallo-β-lactamase alongside the rmtC 16S rRNA methyltransferase, conferring resistance to most β-lactams and every aminoglycoside, respectively. These genes were found on an IncC plasmid that was highly related to an NDM-IncC plasmid retrieved from a ST15 Klebsiella pneumoniae strain circulating in the same hospital two years earlier. Given its ability to acquire resistance plasmids and its intrinsic resistance mechanisms, P. stuartii is a formidable pathogen. The emergence of XDR P. stuartii strains poses a significant public health threat. It is essential to monitor the spread of these strains and develop new strategies for their control and treatment.

Secondary Infections in Patients with Extremely Severe COVID-19 During ECMO Therapy

Up to 70% of patients hospitalized for COVID-19 need respiratory support, up to 10% need high-flow oxygen therapy, non-invasive and invasive ventilation. However, standard methods of respiratory support are ineffective in 0.4-0.5% of patients. In case of potentially reversible critical refractory respiratory failure that patients may require ECMO. Management of patients with extremely severe COVID-19 associates with numerous clinical challenges, including critical illness, multiple organ dysfunction, blood coagulation disorders, requiring prolonged ICU stay and care, use of multiple pharmacotherapies including immunosuppressive drugs. Pharmacological suppression of immunity is associated with a significant increase in the risk of secondary bacterial and fungal infections. Currently, data on epidemiology of secondary infections in patients with COVID-19 undergoing ECMO is limited.Aim. To study the prevalence and etiology of secondary infections associated with positive blood cultures in patients with extremely severe COVID-19 requiring ECMO.Materials and methods. A single-center retrospective non-interventional epidemiological study including 125 patients with extremely severe COVID-19 treated with ECMO in April 2020 to December 2021.Results. Out of 700 blood culture tests performed in 125 patients during the study, 250 tests were positive confirming bacteremia/fungemia. Isolated pathogens varied depending on the duration of ECMO: gram-positive bacteria (primarily coagulase-negative staphylococci) dominated from the initiation of ECMO support; increased duration of ECMO associated with an increasing the proportion of pathogens common in ICU (Klebsiella pneumoniae and/or Acinetobacter baumannii with extensively drug resistant and pan-drug resistant phenotypes, and vancomycin-resistant Enterococcus faecium). When ECMO lasted more than 7-14 days, opportunistic pathogens (Candida species, Stenotrophomonas maltophilia, Providencia stuartii, non-diphtheria corynebacteria, Burkholderia species and others) prevailed as etiological agents.Conclusion. Longer duration of ECMO resulted in increasing the rates of infectious complications. In patients undergoing ECMO for more than 14 days, the microbiological landscape becomes extremely diverse, which hampers choosing an empirical antimicrobial therapy. Since potential pathogens causing secondary infections in patients during ECMO are difficult to predict, rapid identification of rare opportunistic pathogens and their sensitivity profile, followed by targeted administration of antimicrobials, seems most beneficial.

Antibacterial potential and modes of action of botanicals from Momordica foetida (Cucurbitaceae) against multidrug-resistant bacteria expressing active efflux pumps

Background: Momordica foetida (cucurbitaceae) known as a bitter cucumber in Cameroon is used as a medicinal plant. This plant is widely used in the treatment of microbial infections, diabetes, hypertension, stomach, and intestinal irritation. The leaves are also used to treat malaria, earache, and toothache. This study aimed at investigating the antibacterial activity of the methanol extract of M. foetida seeds against multidrug-resistant bacteria expressing active efflux pumps and to characterize the mode of action of this extract. Methods: The antibacterial activity of the crude extract of M. foetida in the presence and absence of an efflux pump inhibitor, phenylalanine-arginine β-naphthylamide (PAβN), was evaluated by the serial micro-dilution method. The determination of the effect of this sample on bacterial H+-ATPase proton pumps was performed by a standard method using a pH meter and the study of the effect of the same sample on cell growth kinetics, bacterial membrane, and biofilms was performed by a spectrophotometric method. Results: The phytochemical composition of the crude extract of M. foetida, evaluated using standard qualitative methods, showed a rather selective distribution of secondary metabolites (presence of polyphenols, flavonoids, alkaloids, triterpenes, sterols, and saponins). The crude extract of this plant virtually inhibited the growth of 90.90% (20/22) of the bacteria studied with minimal inhibitory concentrations (MIC) ranging from 64 to 1024 µg/mL. The lowest MIC of 64 µg/mL was observed against Escherichia coli (AG102, MC4100, W3110), Klebsiella pneumoniae (KP55 and ATCC 11296), Providencia stuartii (NEA16, ATCC 29916 and PS2636), Pseudomonas aeruginosa (PA124) and Staphylococcus aureus (MRSA9) strains. In the presence of PAβN, the activity of the extract was increased against all strains and isolates used. The crude extract caused a prolongation of the lag phase and a general decrease in the growth of Escherichia coli AG102 bacteria due to the blocking of the H+-ATPase proton pumps of this bacterium, resulting in a decrease in the acidity of the medium. This sample destroyed the bacterial membrane and showed significant activity on the biofilms of this strain tested. Conclusion: The results obtained in the present work provide important and significant data that could allow the probable use of Momordica foetida in the control of bacterial infections.

Antibiotic Resistances of Enterobacteriaceae with Chromosomal Ampc in Urine Cultures: Review and Experience of a Spanish Hospital.

The Enterobacteriaceae Citrobacter freundii, Enterobacter cloacae, Klebsiella aerogenes, Morganella morganii, Providencia stuartii, and Serratia marcescens (CESPM group) produce numerous urinary tract infections (UTIs) which are difficult to treat due to their high multiresistance rate. The objectives of this study were to carry out a systematic review of antibiotic resistances by UTIs and to determine changes over time in urine cultures from a reference hospital in southern Spain. The literature was searched for European data on the resistance rates of each microorganism, and a retrospective cross-sectional descriptive study was performed in samples with suspicion of UTI from patients in Virgen de las Nieves University Hospital (Granada, Spain) between 2016 and the first half of 2021. Among 21,838 positive urine cultures, 1.85% were caused by E. cloacae, 0.77% by M. Morganii, 0.65% by K. aerogenes, 0.46% by C. freundii, 0.29% by P stuartii, and 0.25% by S. marcescens. The lowest resistance rates by microorganism were: E. cloacae to amikacin (3.47%) and imipenem (5.28%); M. morganii to piperacillin-tazobactam (1.79%), cefepime (4.76%), and tobramycin (7.74%); K. aerogenes to tobramycin (3.55%), gentamicin (4.25%), trimethoprim-sulfamethoxazole (4.96%), imipenem (5.75%), and cefepime (6.43%); C. freundii to imipenem (no resistance), nitrofurantoin (1.96%), fosfomycin (2.80%), and ertapenem (6.12%); P. stuartii to cefepime (3.28%) and ceftazidime (3.28%); and S. marcescens to gentamicin (1.8%), ciprofloxacin (3.64%), cefepime (3.70%), piperacillin-tazobactam (3.70%), and trimethoprim-sulfamethoxazole (5.45%). In our setting, CESMP Enterobacteriaceae showed the lowest resistance to piperacillin-tazobactam, cefepime, imipenem, gentamicin, and colistin, which can therefore be recommended for the empirical treatment of UTIs. The COVID-19 pandemic may have had a clinical impact in relation to the increased resistance of E. cloacae and M. morgani to some antibiotics.

Ceftazidime-avibactam, meropenem-vaborbactam, and imipenem-relebactam activities against multidrug-resistant Enterobacterales from United States Medical Centers (2018–2022)

A total of 35,360 Enterobacterales isolates were consecutively collected from 75 US medical centers in 2018–2022. Among these isolates, 2612 (7.4%) were categorized as multidrug-resistant (MDR). Isolates were susceptibility tested by reference broth microdilution methods. Carbapenem-resistant Enterobacterales (CRE) were screened for carbapenemase (CPE) genes by whole genome sequencing. The highest MDR rates was observed among Klebsiella pneumoniae (12.2%), followed by Raoultella spp. (10.9%) and Providencia stuartii (9.8%). Ceftazidime-avibactam and meropenem-vaborbactam were very active and showed identical susceptibility rates against MDR isolates (97.9%). Imipenem-relebactam (93.5% susceptible [S]) exhibited slightly lower susceptibility rates due to its limited activity against Morganellaceae family. The most active β-lactamase inhibitor combination (BLI) against CRE isolates (n = 310) was ceftazidime-avibactam (84.2%S), followed by meropenem-vaborbactam (81.9%S) and imipenem-relebactam (74.8%S). All 3 BLIs were very active against KPC producers and none were active against MBL producers. Ceftazidime-avibactam exhibited greater activity against OXA-48–type producers than meropenem-vaborbactam and imipenem-vaborbactam.

Update on the Effect of the Urinary Microbiome on Urolithiasis.

Microbiota are ecological communities of commensal, symbiotic, and pathogenic microorganisms. The microbiome could be involved in kidney stone formation through hyperoxaluria and calcium oxalate supersaturation, biofilm formation and aggregation, and urothelial injury. Bacteria bind to calcium oxalate crystals, which causes pyelonephritis and leads to changes in nephrons to form Randall's plaque. The urinary tract microbiome, but not the gut microbiome, can be distinguished between cohorts with urinary stone disease (USD) and those without a history of the disease. In the urine microbiome, the role is known of urease-producing bacteria (Proteus mirabilis, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Providencia stuartii, Serratia marcescens, and Morganella morganii) in stone formation. Calcium oxalate crystals were generated in the presence of two uropathogenic bacteria (Escherichia coli and K. pneumoniae). Non-uropathogenic bacteria (S. aureus and Streptococcus pneumoniae) exhibit calcium oxalate lithogenic effects. The taxa Lactobacilli and Enterobacteriaceae best distinguished the healthy cohort from the USD cohort, respectively. Standardization is needed in urine microbiome research for urolithiasis. Inadequate standardization and design of urinary microbiome research on urolithiasis have hampered the generalizability of results and diminished their impact on clinical practice.

INVESTIGATING THE ANTIBACTERIAL, ANTIOXIDANT, AND ANTI-INFLAMMATORY ACTIVITIES OF AQUEOUS AND HYDROETHANOLIC EXTRACTS OF OCIMUM BASILICUM AND OCIMUM GRATISSIMUM ON SOME GERMS RESPONSIBLE FOR AEROBIC VAGINITIS

Objective: The present work evaluates the antibacterial, antioxidant, and anti-inflammatory activities of aqueous and hydroethanolic extracts of Ocimum basilicum and Ocimum gratissimum on germs responsible for aerobic vaginitis. Methods: University Teaching Hospital of Yaoundé and Central Hospital of Yaoundé provided the germ (Staphylococcus aureus) and isolates (Enterobacter cloacae and Providencia stuartii). The extracts were obtained by maceration of the plants in water and hydroethanolic system. Phytochemical screening was assessed using the standard method; sensitivity and inhibition tests were carried out on agar medium and microplates in liquid medium. The antioxidant activity of the extracts was evaluated using the 2,2-diphenyl-1-picrilhidrazil (DPPH), 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power assay (FRAP), and β-carotene assays; total polyphenols content was obtained by the Folin Ciocalteu assay; anti-inflammatory activity by denaturation of ovalbumin. Results: Flavonoids, catechin, and tannins were abundant in the hydroethanolic extracts (56.65±3.89 and 228.94±8.42 mg EAA/g, respectively). The extracts were bactericidal for S. aureus and bacteriostatic for P. stuartii and E. cloacae. The hydroethanolic extract of the leaves of O. gratissimum has the best anti-radical activity 23.08±3.12, while that of the leaves of O. basilicum had the best-reducing power (388.36±9.96). The anti-inflammatory activity was found to be significant in the leaf extracts studied with IC50 values ​​of 0.358±0.013 mg/ml for O. basilicum to 0.269±0.008 mg/ml for O. gratissimum, thus justifying their anti-inflammatory properties. The equivalent contents of primary and secondary antioxidants of the extracts were also obtained. Conclusion: The hydroethanolic extracts of Ocimum basilicum and Ocimum gratissimum have antibacterial, antioxidant, and anti-inflammatory properties.

ИНФОРМАТИВНОСТЬ ТРАДИЦИОННОГО МИКРОБИОЛОГИЧЕСКОГО АНАЛИЗА ПРИ СЕПСИСЕ У ПАЦИЕНТОВ НЕЙРОРЕАНИМАЦИОННОГО ПРОФИЛЯ

Background. The existing routine methods of identification of microbes in various biological environments of the body have not led to a radical improvement in the target selection of antimicrobials and the outcomes of septic conditions. The purpose of the study: to analyze the effectiveness of standard microbiological studies in sepsis in patients with brain damage of various origins. Material and methods. A retrospective cohort study included 40 patients (male – 23, female – 17, average age – 50.43±2.84 years) neuro-resuscitation profile. The importance of the most important microbiological patterns of biological media in survived and deceased patients from sepsis has been studied. Results. Acinetobacter baumani, Escherichia coli in urine, Providencia stuartii in tracheobronchial aspirate were detected only in deceased patients, which the presence of these microorganisms can be considered adverse prognostic factors in sepsis and septic shock. Conclusion: A decrease in the clinical significance of the traditional method of verification of microbiological cultures in sepsis was revealed.

Problem of antibiotic resistance in urinary tract infection in ALdiwaniyah city, Iraq

Objective: To identify the most common UTI-causing bacteria in the study samples and to identify the most culture-sensitive antibiotics. Methodology: The study was conducted at Adiwahiyah Teaching Hospital in Iraq's mid-Euphrates area from January 15, 2018 to September 2, 2019. The research included 400 Iraqi patients ages 2 to 85 with UTI symptoms. Results: E. coli was sensitive to imipenem, meropenem, amikacin, and chloramphenicol. Klebsiella pneumoneae was sensitive to amikacin, imipenem, and meropenem. Enterobacter aerogenes was sensitive to imipenem, chloramphenicol, amikacin, and meropenem. Morganella morganii was sensitive to imipenem, meropenem, amikacin, and chloramphenicol. Trimethoprim-sulphamethoxazole, trimethoprim, tetracycline, and doxycycline were effective against Proteus mirabilis. Imipenem and meropenem were effective against Pantoea agglomerans. Amikacin, imipenem, and meropenem were effective against Providencia stuartii. Serratia marcescens was susceptible to trimethoprim-sulphamethoxazole, trimethoprim, amikacin, chloramphenicol, imipenem, and meropenem. Conclusion: In the current study, in order of frequency, the most frequently isolated bacteria were E. coli, followed by Staph aureus. The study showed that the three best antibiotics for almost all isolated bacteria were imipenem, meropenem and amikacin with very minor exceptions.

Antibiogram, Genomic and Phylogeny of Stool and Seafood Isolates from Some Cholera-Prone Coastal Communities in Rivers State, Nigeria

Cholera is a significant public health threat across the globe, especially in coastal regions with poor water supply. This study was carried out to determine the antibiogram, genomic, and phylogeny of stool and seafood isolates from some cholera-prone coastal communities in Rivers State, Nigeria. A total of 400 stool samples and 42 different seafood were aseptically collected and examined using standard microbiology and molecular techniques. An antibiogram of isolates from seafood and stool samples was assayed. Genes for virulence, resistance, and relatedness of bacteria identified were also determined. The isolates from the stool and seafood were examined for susceptibility to some selected antibiotics. The findings showed the prevalence rate of cholera in the communities as follows: 16% in Kaa, 30% in Andoni, 4% in Ogu/Bolo, and 10% in Abua/Odual. The isolates from stool were susceptible to Ciprofloxacin and Gentamycin with a susceptibility rate of 94.12% each while 100% resistance was recorded against Amoxicillin-clavulanic acid, 94.12% against Amikacin and 88.24% against Colistin. For the sea foods, the isolates were susceptible to gentamycin and ciprofloxacin with a susceptibility rate of 91.43% and 82.86% respectively. Resistance was also recorded against Colistin (88.57%) and Azithromycin (82.86%). Testing the isolates for the presence of 16SrRNA genes showed that all were positive with 1500 bp 16SrRNA gene band size. TEM, OXA, SHV, and CTX-M resistant genes were detected whereas the virulence genes were TDH and AcrB. The phylogenetic analysis revealed isolates from seafood to be Aeromonas dhakensis, Vibrio parahaemolyticus, Vibrio azureus, and Providencia rettgeri, while in stool samples they were Enterobacter sichuanensis, Enterobacter hormaechei, Providencia sneebia, and Proteus vulgaris. Providencia stuartii, Proteus mirabilis, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae were common isolates from both seafood and stool samples. This study has shown that not all reported cases of cholera are caused by Vibrio cholerae. Therefore, attention should be paid to other water-borne bacteria in every outbreak, especially in coastal communities.

Hospital-acquired infections due to carbapenem-resistant Providencia stuartii.

During the course of a retrospective survey on healthcare associated infections (HAIs) due to carbapenem-resistant organisms, an unusual prevalence of HAIs due to carbapenem-resistant Providencia stuartii (CRPS) was found. Hence this study aimed to conduct the occurrence of P. stuartii associated HAIs with special reference to the drug resistance profiling of these isolates. Of the eight total HAI cases (7.5% of total HAIs and 33.3% of HAIs due to Enterobacterales) of CRPS infections included in this study, three were reported from ventilator-associated pneumonia (VAP), three were surgical site infections (SSIs), one was a catheter-associated urinary tract infection (CAUTI) and one was a bloodstream infection. All the eight CRPS isolates were tested for extended-spectrum β-lactamases production, AmpC hyperproduction as well as carbapenem resistance. Typing of the isolates was performed by repetitive extragenic palindromic polymerase chain reaction (REP-PCR). All the eight isolates of CRPS were found to be AmpC hyperproducers, carbapenemase producers, and harboured chromosomally located blaNDM in seven isolates and blaIMP genes in one. All the cases with CRPS infections had prior history of colistin therapy along with prolonged hospital stay (>20 days). The cases were located in five different wards/intensive care unit (ICU) within the hospital in one year. However, strain typing by REP-PCR revealed 100 per cent similarity and clonal relatedness in all the seven isolates carrying blaNDM genes. Interestingly, routine hospital surveillance revealed a high carriage of P. stuartii in the axilla of patients admitted to the ICU. The study findings suggest CRPS as an important cause of HAIs. This organism often goes unnoticed due to the burden of carbapenem resistance in other Enterobacterales and non-fermenters.