The public health concern of antibiotic residues in animal-origin food has been a long-standing issue. In this work, we present a novel method for antibiotic detection, leveraging optical weak value amplification and harnessing an indirect competitive inhibition assay, which significantly boosts the system\'s sensitivity in identifying small molecule antibiotics. We chose chloramphenicol as a model compound and mixed it with chloramphenicol-bovine serum albumin conjugates to bind to the chloramphenicol antibody competitively. We achieved a broad linear detection range of up to 3.24 ng/mL and a high concentration resolution of 33.20 pg/mL. To further validate the universality of our proposed detection methodology, we successfully applied it to testing gibberellin and tetracycline. Moreover, we conducted regeneration experiments and real-sample correlation studies. This study introduces a novel strategy for the label-free optical sensing of small molecule antibiotics, greatly expanding the range of applications for sensors utilizing optical weak value amplification.

Q fever is an important zoonotic disease caused by the pathogen Coxiella burnetii, which is inhaled into the body through the respiratory tract leading to acute symptoms. Severe acute Q fever may result in complications, such as pneumonia, hepatitis, or myocarditis, and some patients may develop chronic Q fever after incomplete treatment. Local persistent C. burnetii infection may lead to chronic Q fever that often requires surgery and anti-infection treatment for several years, seriously endangering patient health and increasing the economic burden for families. The clinicians\' lack of awareness of the disease may be one reason leading to a delay in treatment. Here, a case of Q fever in a 53-year-old male patient, which was diagnosed by next generation sequencing and exhibited a distinct computed tomographic feature, is reported, with the aim of improving clinical knowledge of this disease. Following diagnosis, the patient was treated with 0.1 g doxycycline, orally, twice daily, and 0.5 g chloramphenicol, orally, three times daily, leading to improvement of symptoms and discharge from hospital.

Effective therapies for multidrug-resistant (MDR) microorganisms, especially Gram-negative bacteria, are becoming rare. Also, solid-organ transplant recipients are at high risk of MDR Gram-negative bacilli infection. Urinary tract infections are the most frequent bacterial infections in kidney transplant recipients and are an important cause of mortality after renal transplantation. We describe a case of complicated urinary tract infection in a kidney transplant patient due to extensively drug-resistant (XDR) K. pneumoniae treated successfully with a regimen comprising a combination of chloramphenicol and ertapenem. We do not recommend chloramphenicol as a first-line choice for treating complicated urinary tract infections. Still, we believe it is an alternative for infections caused by MDR and/or XDR pathogens in renal transplant patients, as other options are nephrotoxic.

BACKGROUND: Fusarium species are saprophytic fungi with a worldwide distribution. These fungi cause various infections among immunocompromised patients; however, they can also involve immunocompetent individuals.
METHODS: We report a case of a 41-year-old Iranian woman who presented with ulcerative lesions on her lips 10 months ago. She had a long history of anxiety but had no history of classical risk factors such as trauma, cosmetic lip tattoo, burning in her lips, smoking or use of alcohol and opium. A skin biopsy from the lower lip was performed and sent for microbiological examinations. Hyaline septate hyphae were seen on direct microscopy with potassium hydroxide. The clinical specimen was subcultured on sabouraud dextrose agar with chloramphenicol and prepared for antifungal susceptibility testing and molecular identification. Considering the minimum inhibitory concentrations (MIC) for antifungals, itraconazole (100 mg orally twice a day) was started for her, and after 2 months, the lesions were treated. She followed up for 3 months, and no signs of disease recurrence were observed.
CONCLUSIONS: Selecting an appropriate treatment strategy according to the laboratory assessments is essential in clinical practice and the management of rare infections to prevent related mortality and morbidity of opportunistic fungal infections.

Despite the utilization of external magnetic field (MF) in promoting the intrinsic unique features of magnetic nanomaterials in many different applications has been reported, however the origin of MF-dependent electrochemical behaviors as well as the electrochemical response of analytes at the electrode in sensor applications is still not clear. In this report, the influence of MF on the electrolyte\'s physicochemical properties (polarization, mass transport, charge/electron transfer) and electrode\'s properties (conductivity, morphology, surface area, interaction, adsorption capability, electrocatalytic ability) was thoroughly investigated. Herein, the working electrode surface was modified with carbon spheres (CSs), magnetic nanoparticles (Fe3O4NPs), and their nanocomposites (Fe3O4@CSs), respectively. Then, they were directly used to enhance the electrochemical characteristics and response-ability of chloramphenicol (CAP). More interestingly, a series of various kinetic parameters related to the diffusion-controlled process of K3[Fe(CN)6]/K4[Fe(CN)6)] and the adsorption-controlled process of CAP were calculated at the bare electrode and the modified electrodes with and without the presence of MF. These parameters not only exhibit the crucial role of the modification of electrode surface with the proposed materials but also show positive impacts of the presence of external MF. Besides, the mechanism and hypothesis for the enhancements were proposed and discussed in detail, further demonstrating the development potential of using Fe3O4@CS nanocomposites with MF assistant for advanced energy, environmental, and sensor related-applications.

Antibiotics are a type of antimicrobial drug with the ubiquitous presence in foodstuff that effectively applied to treat the diseases and promote the animal growth worldwide. Chloramphenicol as one of the antibiotics with the broad action spectrum against Gram-positive and Gram-negative bacteria is widely applied for the effective treatment of infectious diseases in humans and animals. Unfortunately, the serious side effects of chloramphenicol, such as aplastic anemia, kidney damage, nausea, and diarrhea restrict its application in foodstuff and biomedical fields. Development of the sufficiently sensitive methods to detect chloramphenicol residues in food and clinical diagnosis seems to be an essential demand. Biosensors have been introduced as the promising tools to overcome the requirement. As one of the newest types of the biosensors, aptamer-based biosensors (aptasensors) are the efficient sensing platforms for the chloramphenicol monitoring. In the present review, we summarize the recent achievements of the accessible aptasensors for qualitative detection and quantitative determination of chloramphenicol as a candidate of the antibiotics. The present chloramphenicol aptasensors can be classified in two main optical and electrochemical categories. Also, the other formats of the aptasensing assays like the high performance liquid chromatography (HPLC) and microchip electrophoresis (MCE) have been reviewed. The enormous interest in utilizing the diverse nanomaterials is also highlighted in the fabrication of the chloramphenicol aptasensors. Finally, some results are presented based on the advantages and disadvantages of the studied aptasensors to achieve a promising perspective for designing the novel antibiotics test kits.

Urban agricultural soils can be an important reservoir of antibiotic resistance, and have great food safety and public health indications. This study investigated antibiotic-resistant bacteria and antibiotic resistance genes in urban agricultural soils using phenotypic and metagenomic tools. In total, 207 soil bacteria were recovered from 41 soil samples collected from an urban agricultural garden in Detroit, MI, USA. The most prevalent antibiotic resistance phenotype demonstrated by Gram-negative bacteria was resistance to ampicillin (94.2%), followed by chloramphenicol (80.0%), cefoxitin (79.5%), gentamicin (78.4%) and ceftriaxone (71.1%). All Gram-positive bacteria were resistant to gentamicin, kanamycin and penicillin. Genes encoding resistance to quinolones, β-lactams and tetracyclines were the most prevalent and abundant in the soil. qepA and tetA, both encoding efflux pumps, predominated in the quinolone and tetracycline resistance genes tested, respectively. Positive correlation (P<0.05) was identified among groups of antibiotic resistance genes, and between antibiotic resistance genes and metal resistance genes. The data demonstrated a diverse population of antibiotic resistance in urban agricultural soils. Phenotypic determination together with soil metagenomics proved to be a valuable tool to study the nature and extent of antibiotic resistance in the environment.

BACKGROUND: Purpura fulminans is an acute life-threatening disorder characterized by intravascular thrombosis and hemorrhagic infarction of the skin complicated with disseminated intravascular coagulation. It is commonly seen in acute infections following meningococcal and streptococcal infections. Few cases of purpura fulminans following rickettsial infections have been described in the literature.
METHODS: We report a case of a 55-year-old Sri Lankan woman who presented to Teaching Hospital Peradeniya with a febrile illness, headache, and myalgia that progressed to an erythematous rash starting over the bilateral lover limbs and hands and that became black and necrotic with a few hemorrhagic blebs. She had normocytic anemia, platelet clumps, and monocytosis as well as a deranged clotting profile. The result of immunofluorescence antibody testing for rickettsial immunoglobulin G was strongly positive for Rickettsia conorii with a rise in titer convalescent sera, and a diagnosis of purpura fulminans following rickettsial infection was made. The patient made an excellent recovery with chloramphenicol treatment.
CONCLUSIONS: The treating physician should consider the rare but very treatable condition of rickettsial infection as a differential diagnosis in the etiological diagnostic workup of patients presenting with severe purpuric and hemorrhagic rash with fever.

In this article we thoroughly investigated the physical stability of the amorphous form of a chloramphenicol drug. The tendency toward recrystallization of this drug has been examined (i) at nonisothermal conditions by means of a DSC technique; (ii) at isothermal conditions and temperature close to Troom by means of dielectric spectroscopy; (iii) at isothermal conditions and elevated temperatures of T = 323 K and 338 K by dielectric spectroscopy; and (iv) at conditions imitating the manufacturing procedure (i.e., elevated temperature and compression procedure). Our investigations have shown that amorphous chloramphenicol, stored at both standard storage and elevated temperature conditions, does not reveal a tendency toward recrystallization. However, compression significantly changes this behavior and destabilizes the examined compound. We found that due to chemical equilibration of the sample, the elongation of the storage time before compression might improve the physical stability of the examined pharmaceutical exposed to compression 34-times.

Phenytoin toxicity masquerading as deterioration of neurological symptoms caused by interaction with chloramphenicol is a very rare but real risk. To the authors’ knowledge only one such case occurring in humans has been reported in the English literature. No case of clinical phenytoin toxicity occurring at less than double the serum phenytoin therapeutic levels, occurring as a result of chlorampenicol interaction has been documented, hence our report. A 17 year old man, whose frontal subdural empyema had been drained, had his seizures well controlled on phenytoin. Shortly after, he had a parasagital subdural empyema which was also drained. He was put on chloramphenicol. He improved tremendously until he then developed cerebellar symptoms. Phenytoin levels were noted to be almost twice the maximum therapeutic value. On stopping chloramphenicol, phenytoin levels normalized and symptoms resolved. Possibility of phenytoin toxicity should always be entertained in patients who are also taking chlorampenicol, presenting with new or worsening neurological symptoms.