Salmonella enterica serovar Infantis is an emerging non-typhoidal Salmonella (NTS) serovar increasingly associated with foodborne gastroenteritis. Human infections caused by this serovar remain underreported in India. We report a case of acute gastroenteritis caused by Salmonella enterica serovar Infantis in a 53-year-old male from South India. The patient presented with acute-onset watery diarrhoea for six days associated with intermittent fever and recent outside food consumption. Stool culture yielded non-lactose fermenting colonies identified by automated identification using the VITEK-2 Compact system as Salmonella group, which was subsequently confirmed as Salmonella enterica serovar Infantis by the National Institute for Research in Bacterial Infections, Kolkata, India. Antimicrobial susceptibility testing revealed susceptibility to ceftriaxone, cefepime, carbapenems, ciprofloxacin, and trimethoprim/sulfamethoxazole, while resistance to aminoglycosides and cefuroxime-axetil was observed. The patient improved clinically with ceftriaxone therapy and supportive management. This case highlights the emerging clinical importance of S. Infantis in India and underscores the necessity of routine serotyping, antimicrobial susceptibility testing, and strengthened surveillance to monitor evolving resistance patterns and public health risks associated with NTS infections.

The emergence of KPC variants associated with ceftazidime/avibactam resistance may also compromise the activity of other recently developed β-lactams, including cefiderocol and cefepime/taniborbactam. Xeruborbactam is a boronic acid β-lactamase inhibitor with potent activity against serine- and metallo-β-lactamases and is currently under clinical development in combination with cefiderocol. We evaluated the in vitro activity of cefiderocol/xeruborbactam against a panel of clinical Klebsiella pneumoniae isolates and isogenic Escherichia coli transformants (including both wild-type and porin-deficient backgrounds) producing KPC variants. Xeruborbactam and taniborbactam activities were compared using ceftazidime, cefepime, and cefiderocol as reporter substrates. Inhibitory activity was analyzed by determining the IC50 values for both inhibitors against KPC variants. Most clinical isolates producing KPC variants showed increased MIC values and substantial cross-resistance to ceftazidime/avibactam, cefiderocol, and cefepime/taniborbactam. Cefiderocol/xeruborbactam retained potent activity against all clinical isolates, regardless of the KPC variant produced or the outer membrane permeability status. These findings were confirmed in wild-type and porin-deficient isogenic E. coli models, in which the combination of KPC variants and porin loss synergistically increased resistance to multiple β-lactams, while cefiderocol/xeruborbactam consistently restored susceptibility to wild-type levels. Comparative MIC analyses showed that xeruborbactam enhanced the activity of all β-lactam partners to a greater extent than taniborbactam. IC50 determinations revealed a 17-fold to 73-fold greater inhibitory potency of xeruborbactam, which was maintained across structurally diverse KPC variants. Overall, cefiderocol/xeruborbactam exhibited potent activity against KPC-producing Enterobacterales, including isolates producing KPC variants associated with reduced susceptibility or resistance to ceftazidime/avibactam, cefiderocol, and cefepime/taniborbactam.

Antimicrobial resistance (AMR) in Salmonella enterica from aquatic animals represents an emerging food safety and public health concern, yet the global distribution patterns and trends remain insufficiently understood. Here, we performed a global genomic survey of Salmonella from aquatic animals using 2911 genomes collected from 67 countries across six continents between 1974 and 2025. These genomes represented 194 serovars and 364 sequence types. Notably, the dataset exhibited unbalanced geographical sampling, with Asian isolates accounting for 69.98% of all strains, which may limit the generalizability of our global trends. Globally, resistance to WHO-recommended clinically important antimicrobials showed substantial variation among antibiotic classes, with resistance rates for azithromycin (2.10%), cefepime (2.89%), cefotaxime (2.71%), ceftazidime (2.71%), and ceftriaxone (0.62%). Geographical differences were observed, with isolates from Asia exhibiting higher resistance levels, particularly for ciprofloxacin (13.50%) and doxycycline (18.02%). AMR temporal trends differed across geographical regions. A total of 111 acquired ARGs and 10 resistance-associated chromosomal mutations were identified, accompanied by changes in the distribution of resistance determinants. Collectively, this study provides a global genomic perspective on priority AMR in Salmonella from aquatic animals and highlights the importance of integrating aquaculture, environmental, and public health surveillance to monitor and mitigate AMR risks within the One Health framework.

Extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae causes difficult-to-treat bloodstream infections in patients with haematological malignancies, particularly after allogeneic haematopoietic stem cell transplantation (allo-HSCT). Carbapenems remain reliable, but their anti-anaerobic activity may aggravate intestinal dysbiosis and increase selection pressure for carbapenem resistance. Cefepime-enmetazobactam is a novel fourth-generation cephalosporin/β-lactamase inhibitor combination active against many class A ESBL-producing Enterobacterales. We describe a profoundly immunocompromised patient with acute myeloid leukaemia after allo-HSCT, grade III steroid-refractory gastrointestinal graft-versus-host disease, and intestinal colonization by an ESBL-producing K. pneumoniae isolate resistant to ceftolozane-tazobactam. The patient developed persistent bacteraemia and right pyelonephritis with small renal abscess-like lesions. Meropenem was rapidly de-escalated to cefepime-enmetazobactam, with temporary adjunctive fosfomycin and subsequently tigecycline. Blood-culture time to positivity progressively lengthened from 1.18 h to 16 h before cultures became negative. Serial cefepime therapeutic drug monitoring permitted repeated assessment of exposure and neurological toxicity risk. Whole-genome sequencing identified K. pneumoniae ST307 carrying blaCTX-M-15, blaTEM-1, blaSHV-28, and blaOXA-1, together with multiple resistance determinants and a large conjugative plasmid. This case describes the use of cefepime-enmetazobactam as part of a targeted carbapenem-sparing strategy for invasive ESBL-producing K. pneumoniae infection in a highly immunocompromised allo-HSCT recipient.

Antimicrobial resistance (AMR) in Gram-negative pathogens represents a critical global health challenge. Combining cefepime with novel β-lactamase inhibitors (enmetazobactam, taniborbactam, zidebactam, and nacubactam) revitalizes the role of this fourth-generation cephalosporin in contemporary therapy. We present a narrative review according to the Scale for the Assessment of Narrative Review Articles (SANRA) criteria, summarizing the existing literature regarding new cefepime combinations with β-lactamase inhibitors. Based on 68 identified studies, data were structured by molecule. Each section explores in vitro activity, preclinical in vivo data, PK/PD parameters, clinical evidence, and dosage. Findings demonstrate that these inhibitors successfully restore cefepime's efficacy against diverse resistance mechanisms, notably ESBLs, AmpC, KPC, OXA-48, and metallo-β-lactamases. "Cefepime 2.0" therapies expand the therapeutic armamentarium against severe multidrug-resistant infections, offering vital carbapenem-sparing strategies. Because they possess distinct microbiological spectra, these agents serve complementary rather than interchangeable roles. Their clinical success demands targeted integration into antimicrobial stewardship programs to optimize efficacy and safely reduce carbapenem dependence.

One of the most important adverse consequences of antibiotic use is the development of bacterial resistance. This study investigated the prevalence and antimicrobial resistance patterns of multidrug-resistant (MDR) Escherichia coli in a tertiary care hospital during 2013-2015 and 2024, together with trends in antibiotic consumption and the molecular characteristics of resistance genes in 2024 isolates. Identification and susceptibility testing were performed using the Vitek[®] 2 system, antibiotic consumption was assessed according to WHO ATC/DDD methodology, and resistance genes were detected by PCR. No significant differences were observed in the total number of isolates, patients, or the proportion of E. coli isolates during 2013-2015. However, the isolation rate of MDR E. coli significantly declined from 36.9% to 30%. Total antibiotic consumption remained stable, with no correlation between consumption and MDR isolation rates, although ampicillin resistance increased significantly. In 2024, MDR E. coli accounted for 24.3% of isolates despite lower antibiotic consumption. Compared with 2015, resistance significantly increased to amoxicillin-clavulanic acid, cefotaxime, cefepime, ceftazidime, ciprofloxacin, and levofloxacin, while ceftriaxone resistance decreased. The blaCTX-M gene was detected in 53% of bloodstream isolates, indicating widespread dissemination of ESBL-producing E. coli and highlighting the need for continuous surveillance and antimicrobial stewardship.

Background/Objectives: Antibiotic-associated encephalopathy (AAE) is a serious adverse reaction whose presentation is thought to differ between antibiotics; whether these agent-specific profiles are consistently reflected in spontaneous reports across independent data sources is unknown. Methods: Using the Japanese Adverse Drug Event Report (JADER) database and the US FDA Adverse Event Reporting System (FAERS, 2004-2026), we studied metronidazole, cefepime, ceftriaxone, ceftazidime, and levofloxacin. Encephalopathy was defined by the MedDRA terms Encephalopathy or Toxic encephalopathy, and reporting odds ratios (RORs) were calculated in each database; co-reported neurological manifestations, time to onset, patient age, and renal-associated terms were then characterized. Results: All five antibiotics showed significant reporting disproportionality in both databases, with metronidazole and cefepime showing the largest RORs in each (JADER: metronidazole ROR 186.70, cefepime 55.33; FAERS: cefepime 69.29, metronidazole 29.11), consistent with established adverse reactions. In FAERS, metronidazole showed a cerebellar profile (ataxia OR 12.48, dysarthria OR 11.11) and cefepime a renal-associated altered-mental-status/myoclonus profile (depressed level of consciousness OR 12.88, myoclonus OR 11.76; renal-associated terms OR 2.88; median age 71 years); event-specific JADER dates indicated a delayed course for metronidazole (median 28 days). The symptom-level contrast was FAERS-based and was not reproduced when the same analysis was repeated in JADER, a discrepancy that may reflect differences in coding practice. Conclusions: AAE is reported not as a single uniform event but with profiles specific to the causative antibiotic. Awareness of these agent-specific patterns may support earlier recognition, although confirmation in analytic studies with exposure denominators is warranted.

Background and Clinical Significance: Sodium-glucose cotransporter-2 (SGLT2) inhibitors cause persistent glucosuria, which has been hypothesized to facilitate urinary tract infection (UTI) when urinary stasis or anatomic variants coexist; causality, however, remains unproven and almost certainly multifactorial. Case Presentation: A 72-year-old man treated with dapagliflozin 10 mg/day for 4 months presented with 3 days of dysuria and nocturia, without fever or systemic signs. One month before SGLT2 inhibitor initiation, urological work-up had been unremarkable: prostate ~50 cm[3], post-void residual (PVR) 0 mL, and a negative midstream culture. At presentation we obtained a midstream clean-catch specimen before antibiotics. Dipstick showed glucose 2+ (~100 mg/dL, as expected with SGLT2 inhibition), leukocyte esterase 3+ and nitrites negative; microscopy revealed 45 leukocytes/high-power field with pronounced bacteriuria. Quantitative culture grew Morganella morganii at 1 × 10[5] CFU/mL in pure culture. Antimicrobial susceptibility (VITEK[®] 2 Compact, EUCAST v14.0, 2024) demonstrated resistance to ampicillin, amoxicillin-clavulanate, ampicillin-sulbactam, ceftriaxone, ceftazidime, gentamicin and trimethoprim-sulfamethoxazole, with susceptibility (S) retained only to piperacillin-tazobactam, levofloxacin/norfloxacin, cefepime and carbapenems (ertapenem, meropenem). Imaging revealed a right duplicated ureter with distal fusion (single bladder insertion, no dilatation or obstruction) and benign prostatic hyperplasia with PVR ~100 mL; renal function was preserved, two blood culture sets (pre-antibiotic) were negative, and repeat urine culture on day 7 was sterile. Management/outcome: The episode was classified as a localized (cystitis-range) UTI per European Association of Urology (EAU) criteria (no fever, flank pain or bacteremia). Meropenem 1 g intravenously every 8 h (3 g/day) was given for 10 days after urology/infectious-disease review. Dapagliflozin was held at presentation and not restarted during the 3-month follow-up period; reintroduction was planned only after full urological reassessment with cardiology input. Transurethral resection of the prostate (TUR-P) was performed 18 days after completing antibiotics (28 days after presentation) for bladder outlet obstruction refractory to tamsulosin 0.4 mg daily, with complete resolution of symptoms, normalization of inflammatory markers and PVR 0 mL. No recurrence occurred during 3 months of follow-up after TUR-P. Conclusions: This single case illustrates a temporal association-not proven causation-between SGLT2-related glucosuria, incomplete emptying and a non-obstructive duplicated ureter that likely created a permissive milieu for opportunistic Morganella UTI. The narrative is hypothesis-generating; urinary stasis was the dominant modifiable factor. Culture-guided therapy, individualized decisions on SGLT2 continuation, and definitive correction of outlet obstruction are the practical takeaways.

Ignatzschineria indica is a rare Gram-negative bacterium increasingly recognized as a potential human pathogen associated with wound myiasis and severe bloodstream infections. Here we report a fatal case of I. indica bacteremia in a 63-year-old woman admitted to the intensive care unit with septic shock. The patient had arterial hypertension and liver cirrhosis and was found after prolonged immobilization in severely neglected conditions. Clinical examination revealed extensive pressure ulcers complicated by maggot infestation and a left pertrochanteric femoral fracture. Blood cultures became positive for Gram-negative rods, with the isolate identified by mass spectrometry as I. indica. Antimicrobial susceptibility tests using gradient diffusion demonstrated susceptibility to all tested antibiotics (cefotaxime, cefepime, meropenem, piperacillin/tazobactam, ciprofloxacin, trimethoprim-sulfamethoxazole and gentamicin). However, despite intensive care management, broad-spectrum antimicrobial therapy, and surgical wound debridement, the patient developed progressive multiorgan failure and died from refractory septic shock. Subsequently, the presence of I. indica in the blood culture was confirmed by whole-genome sequencing, showing a 98.8% average nucleotide identity with the reference genome. This case highlights the pathogenic potential of I. indica in patients with neglected myiasis-associated wounds. The rarity lies particularly in the fact that despite all modern available care (including necrectomy, debridement, and treatment with suitable antibiotics), the patient died within three days of admission. This is unique in Central Europe, where no report on lethal infection with I. indica has been reported so far. Hence, this paper can serve as a valuable piece of knowledge on the treatment of maggot-infested wounds, particularly where I. indica infections are concerned.