The approach to multidrug-resistant (MDR) Gram-negative bacilli (GNB) infections has changed following the introduction of avibactam-based β-lactam/β-lactamase inhibitor combinations. Ceftazidime/avibactam has become a cornerstone for the treatment of infections caused by KPC-producing Enterobacterales, whereas the recent availability of aztreonam/avibactam has provided the first targeted option against metallo-β-lactamase (MBL)-producing Enterobacterales. At the same time, the emergence of KPC variants, the increasing dissemination of MBLs and the growing complexity of resistance mechanisms have made both empirical and targeted therapeutic decisions increasingly challenging. This narrative review summarizes the current evidence regarding the microbiological activity, clinical efficacy and optimal place in therapy of avibactam-based combinations. Ceftazidime/avibactam is a cornerstore for the treatment of KPC infections, and significantly modified the outcome of patients with KPC infections during the last decade. Robust observational studies demonstrated its clinical efficacy and safety. It may also represent a carbapenem-sparing option for treating infections due to difficult-to-treat ESBL- and OXA-48-producing Enterobacterales. Moreover, its activity against MDR Pseudomonas aeruginosa makes it an attractive option for empirical therapy in patients with risk factors for this non-fermenting GNB. Aztreonam/avibactam represents the first-line option for the treatment of MBL-producing Enterobacterales and plays a pivotal role in the current era of increasing dissemination of multiple carbapenemases. Their optimal clinical positioning should rely on optimal use in empirical therapy in patients with rectal colonization with carbapenem-resistant Enterobacterales who develop sepsis or septic shock, antimicrobial stewardship principles and integration of local epidemiology, microbiological data and patient characteristics to maximize efficacy while preserving their long-term activity.
Helicobacter cinaedi is an emerging Gram-negative pathogen, possibly involved in the pathogenesis of atherosclerosis and increasingly recognized as a cause of bacteraemia, cellulitis and vascular infections, particularly in immunocompromised and elderly patients. Infection of vascular grafts by H. cinaedi remains exceedingly rare. We report a case of H. cinaedi infection involving an aortic aneurysm and an aorto-bi-iliac endoprosthesis in an immunocompetent patient, highlighting the diagnostic challenges posed by culture-negative infections and the crucial role of Next-Generation Sequencing (NGS) in pathogen identification and therapeutic management.
Knowledge regarding parasites and the diseases they cause remains limited in the pre-microscopic era. Historical medical records concerning cutaneous parasitic infections often lack precision, leaving our understanding of these conditions in earlier centuries largely speculative. While the history of intestinal parasites is well-documented back to antiquity, literature on cutaneous parasites and filariasis primarily dates only to the late 18th century. However, Cerrahiyetü'l Haniyye - the first illustrated surgical textbook written in 15th century Anatolia - presents these conditions in a manner strikingly consistent with modern clinical understanding. This seminal work offers a definitive, early account of cutaneous parasites, accompanied by detailed clinical descriptions that require no interpretation. Furthermore, the unique arrangement of miniature illustrations depicting surgical procedures performed to treat skin parasites makes an extremely important contribution to the known history of skin parasites.
Background:Carbapenem-resistant Acinetobacter baumannii (CRAB) is a World Health Organization critical-priority pathogen, but the contribution of blaOXA-23 and blaNDM co-carriage to resistance across antimicrobial classes is poorly defined in southern Vietnam. Objectives:To describe the carbapenemase gene profile and antimicrobial susceptibility of clinical A. baumannii isolates from a Vietnamese tertiary hospital, to estimate the association between carbapenemase genotypes and class-level resistance, and to assess the concordance between automated phenotypic carbapenemase prediction and multiplex PCR. Methods:Single-centre, laboratory-based cross-sectional study of 172 non-duplicate clinical A. baumannii isolates collected consecutively over 28 months. Susceptibility was determined on the BD Phoenix M50 system, except colistin, which was tested by reference broth microdilution, and interpreted according to CLSI M100 (2023). Denominators vary by agent and are reported explicitly. Class-level resistance was resistance to at least one tested agent in the class. Six carbapenemase genes were detected by multiplex PCR. Firth penalized logistic regression (reference genotype: blaOXA-51 only) was used to estimate genotype-resistance associations; concordance was assessed using Cohen's κ, sensitivity, specificity and predictive values. Results:158 of 172 isolates (91.9%) met the multidrugresistance definition. blaOXA-51 (98.3%) and blaOXA-23 (83.7%) predominated; blaNDM was detected in 23.3%, and blaOXA-23/blaNDM co-carriage in 16.3% (28/172). Colistin resistance was detected in 3 of 156 evaluable isolates (1.9%). The blaOXA-51/blaOXA-23 genotype was associated with higher odds of resistance in all six classes examined (OR 7.60-18.59, all p ≤0.003). Additional carriage of blaNDM was associated with a further increase for carbapenems (OR 13.10, 95% CI 1.90-90.27), aminoglycosides (16.40, 2.39-112.40), fluoroquinolones (13.10, 1.90-90.27), penicillin/β-lactamase inhibitor combinations (15.31, 2.08-112.97) and trimethoprim/sulfamethoxazole (8.27, 1.36-50.26; all p ≤0.022), but not for extended-spectrum cephalosporins (19.00, 0.90-401.19, p=0.058). The blaOXA-51/blaNDM genotype without blaOXA-23 was not significantly associated with resistance in any class. The BD Phoenix M50 predicted Ambler class D with moderate agreement (κ=0.536) but assigned class B to only 1 of 40 blaNDM-positive isolates (κ = 0.038); all 38 isolates reported as carbapenemase detected, class not determined carried blaNDM. Conclusions:In this collection, blaOXA-23 was the genotype most consistently associated with resistance across multiple antimicrobial classes, and blaNDM was associated with resistance mainly when carried together with blaOXA-23. Automated phenotypic classification rarely assigned NDM-producing isolates to Ambler class B, although a carbapenemase result of undetermined class had a high positive predictive value for blaNDM. These single-centre findings are associative; molecular confirmation and clonality analysis are warranted in comparable settings.
