The HtrA chaperone monitors sortase-assembled pilus biogenesis in Enterococcus faecalis.

Sortase-assembled pili contribute to virulence in many Gram-positive bacteria. In Enterococcus faecalis, the endocarditis and biofilm-associated pilus (Ebp) is polymerized on the membrane by sortase C (SrtC) and attached to the cell wall by sortase A (SrtA). In the absence of SrtA, polymerized pili remain anchored to the membrane (i.e. off-pathway). Here we show that the high temperature requirement A (HtrA) bifunctional chaperone/protease of E. faecalis is a quality control system that clears aberrant off-pathway pili from the cell membrane. In the absence of HtrA and SrtA, accumulation of membrane-bound pili leads to cell envelope stress and partially induces the regulon of the ceftriaxone resistance-associated CroRS two-component system, which in turn causes hyper-piliation and cell morphology alterations. Inactivation of croR in the OG1RF ΔsrtAΔhtrA background partially restores the observed defects of the ΔsrtAΔhtrA strain, supporting a role for CroRS in the response to membrane perturbations. Moreover, absence of SrtA and HtrA decreases basal resistance of E. faecalis against cephalosporins and daptomycin. The link between HtrA, pilus biogenesis and the CroRS two-component system provides new insights into the E. faecalis response to endogenous membrane perturbations.

Rapid detection of ceftriaxone-resistant Salmonella by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry combined with the ratio of optical density.

BACKGROUND: The increased resistance rate of Salmonella to third-generation cephalosporins represented by ceftriaxone (CRO) may result in the failure of the empirical use of third-generation cephalosporins for the treatment of Salmonella infection in children. The present study was conducted to evaluate a novel method for the rapid detection of CRO-resistant Salmonella (CRS). METHODS: We introduced the concept of the ratio of optical density (ROD) with and without CRO and combined it with matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) to establish a new protocol for the rapid detection of CRS. RESULTS: The optimal incubation time and CRO concentration determined by the model strain test were 2 h and 8 µg/ml, respectively. We then conducted confirmatory tests on 120 clinical strains. According to the receiver operating characteristic curve analysis, the ROD cutoff value for distinguishing CRS and non-CRS strains was 0.818 [area under the curve: 1.000; 95% confidence interval: 0.970-1.000; sensitivity: 100.00%; specificity: 100%; P < 10- 3]. CONCLUSIONS: In conclusion, the protocol for the combined ROD and MALDI-TOF MS represents a rapid, accurate, and economical method for the detection of CRS.

Molecular Basis of Influence of A501X Mutations in Penicillin-Binding Protein 2 of Neisseria gonorrhoeae Strain 35/02 on Ceftriaxone Resistance.

The increase in the resistance of mutant strains of Neisseria gonorrhoeae to the antibiotic ceftriaxone is pronounced in the decrease in the second-order acylation rate constant, k2/KS, by penicillin-binding protein 2 (PBP2). These changes can be caused by both the decrease in the acylation rate constant, k2, and the weakening of the binding affinity, i.e., an increase in the substrate constant, KS. A501X mutations in PBP2 affect second-order acylation rate constants. The PBP2A501V variant exhibits a higher k2/KS value, whereas for PBP2A501R and PBP2A501P variants, these values are lower. We performed molecular dynamic simulations with both classical and QM/MM potentials to model both acylation energy profiles and conformational dynamics of four PBP2 variants to explain the origin of k2/KS changes. The acylation reaction occurs in two elementary steps, specifically, a nucleophilic attack by the oxygen atom of the Ser310 residue and C-N bond cleavage in the ß-lactam ring accompanied by the elimination of the leaving group of ceftriaxone. The energy barrier of the first step increases for PBP2 variants with a decrease in the observed k2/KS value. Submicrosecond classic molecular dynamic trajectories with subsequent cluster analysis reveal that the conformation of the ß3-ß4 loop switches from open to closed and its flexibility decreases for PBP2 variants with a lower k2/KS value. Thus, the experimentally observed decrease in the k2/KS in A501X variants of PBP2 occurs due to both the decrease in the acylation rate constant, k2, and the increase in KS.

Ischaemic apoplexy caused by syphilis.

Syphilis is a sexually transmitted disease caused by the spirochaete Treponema pallidum. Patients with untreated syphilis can develop meningovascular syphilis at any stage of the disease. This is a case report of a 44-year-old man displaying two instances of acute vertigo and lateralized paraesthesia. MRI showed infarctions in the left thalamus and capsula interna. Subsequent investigations including cerebral spinal fluid analysis revealed a diagnosis of neurosyphilis. The patient was treated intravenously with benzylpenicillin and ceftriaxone with complete clinical remission.

Ceftriaxone-resistant Salmonella enterica serovar Newport: a case report from South India.

Salmonella enterica serovar Newport is a human pathogen underreported in most developing countries. It is known for causing gastroenteritis and extraintestinal infections. In this case report, we report the case of ceftriaxone-resistant Salmonella enterica serovar Newport from South India, causing acute gastroenteritis in a sixty-year-old female patient having a history of antimicrobial therapy and recent hospital admission. Serovar Newport, especially among antibiotic-exposed patients, poses a significant public health threat due to its ability to acquire multidrug resistance. This emphasizes the necessity for robust surveillance and monitoring of nontyphoidal Salmonella infections, particularly given the limited data on serovar Newport in India. Vigilance in clinical practice and public health initiatives is crucial to effectively address the emergence and spread of multidrug-resistant strains.

Antibiotic utilization at an orthopedic inpatient department in a large governmental hospital in the north of the West Bank, Palestine; a retrospective observational study.

BACKGROUND: Studies evaluating the patterns of antibiotic consumption are becoming increasingly necessary as a result of the increased use of antibiotics and development of antibiotic resistance globally. This study aimed to evaluate the use of antibiotics in in terms of both quantity and quality at the largest surgical hospital in the north of the West Bank, Palestine. METHODS: An observational retrospective study with a total population sampling method was conducted to collect data from the inpatients of the orthopedic departments of a large governmental hospital in the northern West Bank, Palestine. The data were collected from patients' files and evaluated using the anatomical therapeutic chemical and defined daily dose (ATC/DDD) methodology, and the drug utilization 90% (DU90%) index. The ATC/DDD methodology, designed by the World Health Organization (WHO), as a well-trusted and standardized tool that allows measuring and comparing antibiotic utilization across different contexts. Antibiotic prescriptions were classified using the World Health Organization Access, Watch and Reserve classification (WHO AWaRe). RESULTS: Of the 896 patients who were admitted to the hospital in the year 2020 and included in the study, 61.9% were males, and 38.1% were females. The percentage of patients who received antibiotics was 97.0%, and the overall antibiotic usage was 107.91 DDD/100 bed days. The most commonly prescribed antibiotic was cefazolin (50.30 DDD/100 bed days), followed by gentamicin (24.15 DDD/100 bed days) and ceftriaxone (17.35 DDD/100 bed days). The DU90% segment comprised four different agents. Classification of antibiotics according to the WHO AWaRe policy revealed that 75.9% of antibiotics were prescribed from the access list. CONCLUSION: This study comes as part of the efforts exerted to combat the growing problem of antibiotic resistance in Palestine. Our results showed that the consumption of antibacterial agents in the orthopedic unit at a large governmental hospital in Palestine was relatively high. The results of this study provide valuable insights for the decision-makers to create policies aimed at regulating antibiotic prescriptions. This study also aims to provide a look into the antibiotic prescription patterns, offering a clearer understanding of the current situation of antibiotic consumption in Palestine. It also emphasizes the need for antibiotic stewardship and surveillance programs.

First-line treatment with ceftriaxone for Neisseria gonorrhoeae infection less likely to be prescribed to patients with a penicillin allergy label: a retrospective audit of medical records.

Background Gonorrhoea notifications have increased substantially in Australia over the past decade. Neisseria gonorrhoeae is already highly resistant to several antibiotics and so, alternatives to first-line treatment are generally strongly discouraged. The penicillin allergy label (AL) on patient medical records has previously been shown to influence prescribing practices, to the detriment of best-practice management and antimicrobial stewardship. This study aimed to understand how the penicillin AL influences antibiotic selection for gonorrhoea treatment at Canberra Sexual Health Centre. Methods A retrospective chart audit of gonorrhoea cases treated at Canberra Sexual Health Centre between January 2020 and October 2023 (n =619 patients, n =728 cases). Antibiotic selection was assessed according to penicillin AL status. Ceftriaxone selection was assessed according to penicillin allergy severity reported in the medical records and as determined using a validated antibiotic allergy assessment tool. Results Cases with a penicillin AL were more likely to receive antibiotics other than ceftriaxone (n =7/41, 17.1%) than cases without the label (n =8/687, 1.2%, P n =28/41, 68.3%) to apply the assessment tool. Those reported as low-severity in the records were more likely to receive ceftriaxone (n =21/22, 95.5%) than those reported as moderate-high (n =7/11, 63.6%) or unreported (n =6/8, 0.75%). Conclusions Treatment of gonorrhoea in outpatient settings requires an understanding of penicillin allergy, and the ability to quickly and accurately identify penicillin-AL patients who can safely tolerate ceftriaxone. Institutionally endorsed penicillin allergy de-labelling protocols and access to easy-to-navigate prescribing advice within national sexually transmitted infection management guidelines would support this.

Gonorrhoea treatment guideline compliance and influence factors in Guangdong province, China: a cross-sectional survey.

BACKGROUND: The indiscriminate use of antibiotics has accelerated antimicrobial resistance (AMR) in Neisseria gonorrhoeae (NG), emphasising the need to follow treatment guidelines. This study aimed to assess the rate of adherence to standard treatment among patients with gonorrhoea and identify influencing factors. METHODS: A survey was conducted in Guangdong province, China, involving uncomplicated gonorrhoea cases registered in the Chinese Information System for Disease Control and Prevention. Data on demographic characteristics and medical information were collected to determine the standard treatment rate, defined as the proportion of patients receiving treatment according to national guidelines (ie, a single dose of ceftriaxone 250 mg, spectinomycin 2 g, cefotaxime 1 g or other third-generation cephalosporins). Medication choices were documented. χ² tests and multilevel logistic regression were used to analyse factors associated with standard treatment. RESULTS: The survey included 2424 patients with gonorrhoea from 59 hospitals. The standard treatment rate was 30.7% (743/2424), with 36.2% for females and 29.6% for males. Common reasons for substandard treatment included the use of non-guideline medications (42.3%, 710/1681) and incorrect dosing (36.2%, 605/1681). Factors associated with the standard treatment rate included gender, address, educational level, department, physicians' training, number of diagnosed gonorrhoea cases and hospital level. CONCLUSION: The standard treatment rate for gonorrhoea in Guangdong province, China, is below expectations. Comprehensive measures, such as establishing a goal-directed monitoring system and implementing promotional activities, are needed to improve adherence to treatment guidelines.

Surge in Ceftriaxone-Resistant Neisseria gonorrhoeae FC428-Like Strains, Asia-Pacific Region, 2015-2022.

Ceftriaxone-resistant Neisseria gonorrhoeae FC428-like strains have disseminated across the Asia-Pacific region, with a continuous rise in prevalence during 2015-2022. To mitigate the effect of these strains, we advocate for enhanced molecular diagnostics, expanded surveillance networks, and a regionally coordinated effort to combat the global spread of FC428-like strains.

A SEVERE CASE OF NON TYPHOIDAL SALMONELLA ASSOCIATED WITH MULTIPLE ORGAN DAMAGE- CASE STUDY AND LITERATURE REVIEW.

We report a severe case of a 25-year-old girl presented with complaints of weakness, diarrhoea, vomiting, pain in abdomen and hypotension at Infectious Diseases and Clinical Immunology Research Center. From history on 25 February till 29 February she was in India and on 1 march this problem started with watery diarrhoea followed by vomiting. She ate pizza with mushroom following which her condition worsened. Stool culture revealed salmonella nontyphi (nonthyphodal Salmonella)and this is leading cause for gastroenteritis, bacteremia and affects several other bodily system. Her condition deteriorated due to the development of ARDS (acute respiratory distress syndrome) and for this she was on mechanical ventilation. Vitec machine was performed, which identified Salmonella typhi murium. Our goal is to manage and treat this patient well by early diagnosis. She was given ceftriaxone, iv fluids and symptomatic treatment but due to resistance meropenem was started and the patient's condition improved. From serology there was no evidence of immunocompromised state so being a severe case of immunocompetent patient this case reflects the importance of timely diagnosis and management together with food safety practices in population. On follow up she was stable and discharged after 3 weeks. Future research studies need to be continued regarding newer strains, effective treatment strategies and diagnostics to prevent morbidity and mortality.

Tracking the shift in enteric fever trends and evolving antibiotic sensitivity patterns.

Objective: This study aims to examine the frequency of Salmonella Paratyphi found in blood cultures and evaluate the antibiotic susceptibility pattern of Salmonella isolates to different antibiotics. Additionally, the study aims to assess the paradigm shift in the trend of enteric fever caused by Salmonella Typhi (S. Typhi) to Salmonella Paratyphi(S. Paratyphi) . Study Design: Retrospective study. Participant: The study enrolled patients aged 12 years and above diagnosed with enteric fever (positive blood culture) and admitted to Peelamedu Samanaidu Govindasamy Naidu (PSG) Hospital. Interventions: The study analyzed demographic and antibiotic susceptibility profiles of Salmonella isolates collected from 106 enteric fever patients in the hospital between 2010 and 2022. The susceptibility profiles of Salmonella isolates to multiple antibiotics were assessed. Results: There were 106 participants, and 95 (89.62%) of them had enteric fever linked to Salmonella Typhi, while only 11 (10.38%) had enteric fever linked to Salmonella Paratyphi A. From 2010 to 2022, the study discovered a general decline in the prevalence of enteric fever caused by Salmonella species. But between 2014 and 2022, the incidence of enteric fever linked to S. Typhi rapidly increased. Azithromycin (100% , n = 106) and ceftriaxone (99% , n = 105) were highly effective against the Salmonella isolates, whereas nalidixic acid was resisted by 3 isolates (4.72%, n = 3). Conclusion: The study observed a higher incidence of Salmonella Typhi in comparison to Paratyphi A and a greater susceptibility of males to enteric fever. Funding: None declared.

Susceptibility of Neisseria gonorrhoeae against a dual treatment antibiotics regimen in primary health centres in Surabaya, Indonesia.

BACKGROUND AND OBJECTIVES: There were 82.4 million new gonorrhoea cases worldwide in 2020. Dual treatment with ceftriaxone or cefixime and azithromycin or doxycycline is currently recommended for gonorrhoea in Indonesia. However, reduced susceptibility and resistance to cephalosporins and azithromycin are increasing. We evaluated the susceptibility pattern of Neisseria gonorrhoeae to cefixime, ceftriaxone, azithromycin and doxycycline. METHOD: N. gonorrhoeae isolates were obtained from 19 male participants with clinically and laboratory-confirmed gonorrhoea. Antibiotic susceptibility testing was conducted by disc diffusion and interpreted according to Clinical and Laboratory Standards Institute and Centers for Disease Control and Prevention criteria. RESULTS: Reduced susceptibility or resistance was observed against doxycycline in 19 isolates (100%), cefixime in six (31.6%), ceftriaxone in three (15.8%) and azithromycin in zero (0%) isolates. DISCUSSION: A dual treatment regimen with ceftriaxone and azithromycin can still be recommended as first-line therapy for gonorrhoea in Indonesia. Antibiotic susceptibility surveillance of N. gonorrhoeae should be routinely conducted.

[Bilateral facial palsy: an atypical presentation of Lyme disease (a case report)]. / Paralysie faciale bilatérale : une présentation atypique d'une maladie de Lyme (cas clinique).

Lyme neuroborreliosis is a rare zoonosis which can be difficult to diagnose, in particular in low endemic areas. We here report the case of a 35-year-old man presenting with disabling back pain preceded by facial monoplegia, which was wrongly treated as Bell's palsy (paralysis a frigore) and then as post-traumatic lumbosciatica. The onset of facial diplegia allowed for a definitive diagnosis. The patient was treated with ceftriaxone and symptoms gradually improved.

Emergence of Extensively Drug-Resistant Neisseria gonorrhoeae, France, 2023.

Since 2022, Europe has had 4 cases of extensively drug-resistant Neisseria gonorrhoeae, sequence type 16406, that is resistant to ceftriaxone and highly resistant to azithromycin. We report 2 new cases from France in 2023 involving strains genetically related to the 4 cases from Europe as well as isolates from Cambodia.

Interaction of Cephalosporins with Human Serum Albumin: A Structural Study.

Modification of the R1 and R2 side chain structures has been used as the main strategy to expand the spectrum of cephalosporins and impart resistance to hydrolysis by ß-lactamases. These structural modifications also result in a wide range of plasma protein binding, especially with human serum albumin (HSA). Here, we determined the crystal structures of the HSA complexes with two clinically important cephalosporins, ceftriaxone and cefazolin, and evaluated the binding of cephalosporin to HSA by susceptibility testing and competitive binding assay. Ceftriaxone and cefazolin bind to subdomain IB of HSA, and their cephem core structures are recognized by Arg117 of HSA. Tyr161 of HSA changes its rotamer depending on the cephalosporin, resulting in alterations of the cavity shape occupied by the R2 side chain of cephalosporins. These findings provide structural insight into the mechanisms underlying the HSA binding of cephalosporins.

An analytical method using salting-out assisted liquid-liquid extraction to quantify ceftriaxone from micro volumes of human serum.

Ceftriaxone (CTRX) is a commonly used cephalosporin antibiotic. It is suggested that monitoring plasma/serum concentrations is helpful for its safe use. This study aimed to develop and validate an analytical method for measuring CTRX concentrations in human serum according to International Conference on Harmonization guideline M10. Ten microliters of serum sample was purified using a salting-out assisted liquid-liquid extraction procedure with magnesium sulfate. The upper layer was then diluted threefold and analyzed using a liquid chromatography-tandem mass spectrometry-based method with a total run time of 12 min. The linear calibration curve was obtained over the concentration range 5-500 µg/ml. The within-run accuracy varied from 0.2 to 6.5%, and the precision was ≤8.0%. The between-run accuracy and precision ranged from 0.7% to 5.6% and ≤6.4%, respectively. Significant carryover was resolved by injecting four blanks after high-concentration CTRX samples. The recovery rates from spiked serum at low and high concentrations were 44.4 and 43.4%, respectively. Other factors, including selectivity, matrix effects, stability, dilution integrity and reinjection reproducibility also met the acceptance criteria. Serum concentrations in 14 samples obtained from two participants receiving 2 g/day of CTRX were successfully determined using this method.

Obstructed vein delivery of ceftriaxone via poly(vinyl-pyrrolidone)-iodine-chitosan nanofibers for the management of diabetic foot infections and burn wounds.

Superficial skin injuries especially burn injuries and unhealed diabetic foot open wounds remain troubling for public health. The healing process is often interrupted by the invasion of resistant pathogens that results in the failure of conventional procedures outside the clinical settings. Herein, we designed nanofibers dressing with intrinsic antibacterial potential of poly(vinyl-pyrrolidone)-iodine/ poly (vinyl)-alcohol by electrospinning with chitosan encapsulating ceftriaxone (CPC/NFs). The optimized electrospun CPC/NFs exhibited smooth surface morphology with average diameter of 165 ± 7.1 nm, drug entrapment and loading efficiencies of 76.97 ± 4.7 % and 8.32 ± 1.73 %, respectively. The results displayed smooth and uniformed fibers with adequate thermal stability and ensured chemical doping. The enhanced in vitro antibacterial efficacy of CPC/NFs against resistant E. coli isolates and biosafety studies encourage the use of designed nanofibers dressing for burn injuries and diabetic foot injuries. In vivo studies proved the healing power of dressing for burn wounds model and diabetic infected wounds model. Immunofluorescence investigation of the wound tissue also suggested promising healing ability of CPC/NFs. The designed approach would be helpful to treat these infected skin open wounds in the hospitals and outside the clinical settings.

Tricuspid valve infective endocarditis in disseminated gonococcal infection (DGI).

SummaryWe describe a case of culture-negative infective endocarditis due to Neisseria gonorrhoeae, where the application of metagenomics shotgun sequencing in blood played a pivotal role in elucidating the underlying aetiology, guiding targeted therapy and ultimately resulting in the patient's complete recovery. Beyond its immediate clinical impact, prompt treatment bears significant implications for public health. The utilisation of molecular testing emerges as a valuable strategy to enhance diagnostic accuracy, particularly in cases involving fastidious organisms that are infrequently associated with infective endocarditis.

Concomitant use of lansoprazole and ceftriaxone is associated with an increased risk of ventricular arrhythmias and cardiac arrest in a large Japanese hospital database.

OBJECTIVES: To determine whether concomitant use of ceftriaxone and oral or intravenous lansoprazole increases the risk of ventricular arrhythmia and cardiac arrest in the real-world setting in Japan. METHODS: The data analyzed were obtained from the JMDC hospital-based administrative claims database for the period April 2014 to August 2022. Patients who received a proton pump inhibitor (PPI) while receiving ceftriaxone or sulbactam/ampicillin were identified. The frequency of ventricular arrhythmia and cardiac arrest was analyzed according to whether oral or intravenous PPI was concomitant with ceftriaxone or sulbactam/ampicillin. Estimates of the incidence of ventricular arrhythmia and cardiac arrest were then compared among the groups, using the Fine-Gray competing risk regression model. RESULTS: The results showed that the risk of ventricular arrhythmia and cardiac arrest was significantly higher with concomitant ceftriaxone and oral lansoprazole (hazard ratio 2.92, 95% confidence interval 1.99-4.29, P < 0.01) or intravenous lansoprazole (hazard ratio 4.57, 95% confidence interval 1.24-16.80, P = 0.02) than with concomitant sulbactam/ampicillin and oral or intravenous lansoprazole. CONCLUSIONS: Oral and intravenous lansoprazole may increase the risk of ventricular arrhythmia and cardiac arrest in patients who are receiving ceftriaxone.

Nocardia brasiliensis Pyomyositis in an Immunocompetent Patient Following Gardening Activity.

Nocardia pyomyositis in immunocompetent patients is a rare occurrence. The diagnosis may be missed or delayed with the risk of progressive infection and suboptimal or inappropriate treatment. We present the case of a 48-year-old immunocompetent firefighter diagnosed with pyomyositis caused by Nocardia brasiliensis acquired by direct skin inoculation from gardening activity. The patient developed a painful swelling on his right forearm that rapidly progressed proximally and deeper into the underlying muscle layer. Ultrasound imaging of his right forearm showed a 7-mm subcutaneous fluid collection with surrounding edema. Microbiologic analysis of the draining pus was confirmed to be N brasiliensis by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry. After incision and drainage deep to the muscle layer to evacuate the abscess and a few ineffective antibiotic options, the patient was treated with intravenous ceftriaxone and oral linezolid for 6 weeks. He was then de-escalated to oral moxifloxacin for an additional 4 months to complete a total antibiotic treatment duration of 6 months. The wound healed satisfactorily and was completely closed by the fourth month of antibiotic therapy. Six months after discontinuation of antibiotics, the patient continued to do well with complete resolution of the infection. In this article, we discussed the risk factors for Nocardia in immunocompetent settings, the occupational risks for Nocardia in our index patient, and the challenges encountered with diagnosis and treatment. Nocardia should be included in the differential diagnosis of cutaneous infections, particularly if there is no improvement of "cellulitis" with traditional antimicrobial regimens and the infection extends into the deeper muscle tissues.