In vitro Antimicrobial Activity of Ampicillin-Ceftriaxone and Ampicillin-Ertapenem Combinations Against Clinical Isolates of Enterococcus faecalis with High Levels of Aminoglycoside Resistance

This paper reports on the in vitro antimicrobial activity of ampicillin-ceftriaxone and ampicillin-ertapenem combinations against five strains of E. faecalis with high-level aminoglycoside resistance recovered from blood of septicemic patients. Double disk diffusion test and time killing curves were used. A bacteriostatic synergistic effect between ampicillin and ceftriaxone was detected using the disk diffusion assay for three of the five enterococcal strains studied. With the same three isolates enhanced bactericidal activity was also observed using time killing experiments. Overall, for these three strains, after 24 hr of contact, a decrease ≥ 2 log10 from the initial bacterial inoculum was registered with most ampicillin-ceftriaxone combinations, reaching with some of them a colony reduction ≥ 3 log10. This bactericidal interaction was negatively influenced increasing the bacterial inoculum. In all five isolates neither a bacteriostatic nor a bactericidal cooperation was observed for ampicillin combined with 2 mg/l of ertapenem

In vitro antibacterial activity of ceftazidime/avibactam in combination against planktonic and biofilm carbapenemase-producing Klebsiella pneumoniae isolated from blood

Abstract Objectives The aim of this study was to report on in vitro tests of antibacterial activity of ceftazidime/avibactam in combination against planktonic or biofilm KPC carbapenemase-producing Klebsiella pneumoniae (KPC-Kp), the rate of KPC-Kp blood isolates in University of Perugia Hospital over a 5-year period, and their antimicrobial susceptibility patterns. Methods The antibacterial activity of ceftazidime/avibactam in combination with other antimicrobials was assessed against planktonic and biofilm bacteria by Etest and checkerboard assay. A retrospective review of laboratory data was performed to evaluate the rate of KPC-Kp from blood samples and their antimicrobial susceptibility patterns. Results Between 2014 and 2019, 130/4241 (3.1%) KPC-Kp were identified from blood cultures. Their rate increased from 2.3% in 2014–2015 to 4.5% over the last 3 years. Overall, 4.6% (6/130) of KPC-Kp isolates were susceptible to meropenem, 65.4% (85/130) to colistin, 65.1% (84/129) to tigecycline, 34.6% (45/130) to amikacin, 36.2% (42/116) to gentamicin, 40.2% (39/97) to fosfomycin and 91.5% (65/71) to ceftazidime/avibactam. Five of six ceftazidime/avibactam-resistant KPC-Kp were isolated from patients not treated with ceftazidime/avibactam. Synergism was detected both by Etest and checkerboard assay for the combination of ceftazidime/avibactam plus meropenem against planktonic isolates, whilst lower bactericidal activity was observed in biofilm KPC-Kp isolates. Conclusions Our in vitro data suggest that the combination of ceftazidime/avibactam plus meropenem has a synergistic antibacterial activity against planktonic bacteria, whilst a lower activity was detected against biofilm, suggesting worse clinical outcomes whenever biofilm infections are present. Further analyses are required to confirm these results before extending them to clinical practice

Meningitis with cranial polyneuritis and cavernous sinus thrombosis by Borrelia crocidurae: First autochthonous case in Europe

Borrelia crocidurae is endemic in West Africa, where it represents the leading cause of tick-borne relapsing fever (TBRF). TBRF typically presents with high fever and systemic symptoms, followed by recurrent episodes. Neurological complications may occur during febrile relapses. B. crocidurae is considered the most neurotropic agent of TBRF and is associated to severe neurological manifestations i.e. meningitis and encephalitis.To date, European cases of B. crocidurae infection have been reported in travelers returning from endemic areas. We report the first autochthonous case in Europe of B. crocidurae infection, presenting as meningitis with cranial polyneuritis and cavernous sinus thrombosis that were not preceded by classic febrile recurrences. Keywords: Borrelia crocidurae, Europe, Autochthonous, Meningitis, Cranial polyneuritis, Cavernous sinus thrombosi

Management of meningitis caused by multi drug-resistant Acinetobacter baumannii: Clinical, microbiological and pharmacokinetic results in a patient treated with colistin methanesulfonate

This paper reports on a 71- year-old Caucasian male who underwent neurosurgery for an oligodendroglioma, followed by a cranial-sinus fistula and cerebrospinal fluid rhinorrhea. The clinical course was complicated due to an extensively drug-resistant Acinetobacter baumannii meningitis. The patient was treated with colistin methanesulfonate, intrathecal for 24 days and intravenous for 46 days. In addition, the patient received meropenem and teicoplanin to treat a urinary tract infection and a bacterial aspiration pneumonia. Cerebrospinal fluid trough colistin levels resulted above the MIC of A. baumannii. Colistin cerebrospinal fluid concentration did not increase over the treatment period. Meningitis was cured and A. baumannii eradicated. No side effects from the antimicrobial therapy were observed. In conclusion, this case highlights the issues in treating infections caused by resistant Gram negative bacteria and supports previous findings on the efficacy, pharmacokinetic and tolerability of intravenous and intrathecal colistin treatments

Osteosynthesis-associated infection of the lower limbs by multidrug-resistant and extensively drug-resistant Gram-negative bacteria: a multicentre cohort study

Purpose: The purpose of this study was the clinical and therapeutic assessment of lower-limb osteosynthesis-associated infection (OAI) by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacteria (GNB), which have been poorly studied to date. Methods: A prospective multicentre observational study was conducted on behalf of ESGIAI (the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group on Implant-Associated Infections). Factors associated with remission of the infection were evaluated by multivariate and Cox regression analysis for a 24-month follow-up period. Results: Patients (n=57) had a history of trauma (87.7 %), tumour resection (7 %) and other bone lesions (5.3 %). Pathogens included Escherichia coli (n=16), Pseudomonas aeruginosa (n=14; XDR 50 %), Klebsiella spp. (n=7), Enterobacter spp. (n=9), Acinetobacter spp. (n=5), Proteus mirabilis (n=3), Serratia marcescens (n=2) and Stenotrophomonas maltophilia (n=1). The prevalence of ESBL (extended-spectrum β-lactamase), fluoroquinolone and carbapenem resistance were 71.9 %, 59.6 % and 17.5 % respectively. Most patients (n=37; 64.9 %) were treated with a combination including carbapenems (n=32) and colistin (n=11) for a mean of 63.3 d. Implant retention with debridement occurred in early OAI (66.7 %), whereas the infected device was removed in late OAI (70.4 %) (p=0.008). OAI remission was achieved in 29 cases (50.9 %). The type of surgery, antimicrobial resistance and duration of treatment did not significantly influence the outcome. Independent predictors of the failure to eradicate OAI were age &gt;60 years (hazard ratio, HR, of 3.875; 95 % confidence interval, CI95 %, of 1.540–9.752; p=0.004) and multiple surgeries for OAI (HR of 2.822; CI95 % of 1.144–6.963; p=0.024). Conclusions: Only half of the MDR/XDR GNB OAI cases treated by antimicrobials and surgery had a successful outcome. Advanced age and multiple surgeries hampered the eradication of OAI. Optimal therapeutic options remain a challenge.</p

Non-primary nail-plate syphilis in an HIV-infected patient

A 37-year-old Caucasian male, HIV-infected (CDC A2) in 2012 and on antiretroviral therapy, presented for a follow-up visit. On physical examination, a barely discernible light-colored macular rash was observed on the trunk, not involving the palms and soles. However, clear maculo-papular lesions were present over the proximal volar aspect of both forearms. Furthermore, well-demarked purplish, opaque, rough, vertically ridged plaque-like lesions were observed over the proximal portions of fingernails. The patient reported that cutaneous and nail lesions had appeared about 2 months prior and that he had engaged in unprotected sex 5 months before. Serologic tests for syphilis resulted reactive. Intramuscular injection of benzathine penicillin G, 2.4 million units, was administered once a week for 3 weeks. One month after therapy, the rash was no longer present, and at 5 months, nail abnormalities had disappeared. The clinical findings, the serologic results, and the disappearance of skin and nail lesions after the administration of penicillin strongly suggest that this HIV-infected patient had secondary or early late syphilis with skin and nail-plate involvement. We are experiencing a resurgence of syphilis as well as an increase in unusual and/or forgotten clinical manifestations. Syphilis remains a diagnostically challenging diseas

Stroke in a patient with tuberculous meningitis and HIV infection

Abstract. Tuberculous meningitis (TBM) is a devastating disease. TBM occurs more commonly in HIV infected patients. The influence of HIV co-infection on clinical manifestations and outcome of TBM is not well defined. Yet, some differences have been observed and stroke has been recorded to occur more frequently. This study reports on an HIV infected Caucasian female with lung, meningeal tuberculosis and stroke due to a cortical sub-cortical ischemic lesion.TBM was documented in the absence of neurologic symptoms. At the same time, miliary lung TB caused by multi-susceptible Mycobacterium tuberculosis was diagnosed. Anti-TB therapy consisting of a combination of four drugs was administered. The patient improved and was discharged five weeks later. In conclusion, TBM and multiple underling pathologies including HIV infection, as well as other risk factors can lead to a greater risk of stroke. Moreover, drug interactions and their side effects add levels of complexity. TBM must be included in the differential diagnosis of HIV infected patients with stroke and TBM treatment needs be started as soon as possible before the onset of vasculopathy

Diagnostic considerations about visceral leishmaniasis. Two case report

Two cases of visceral leishmaniasis (VL) in immunocompetent patients have been described. Both patients lived in endemicic areas for leishmaniasis in the south of Italy, tested positive for anti-Leishmania antibodies. A definitive diagnosis of VL was delayed by false negative microscopic examinations. Both patients were treated successfully with liposomal amphotericin B