Multidrug-Resistant Klebsiella Pneumoniae in Native Portuguese Cattle Breeds: A Public Health Concern

Ricardo Faria; Rui Dantas; Luís Pinho; Ana R. Freitas; Nuno V. Brito; Sandra Quinteira; Carla Miranda

Previous Article in event

In Silico Exploration of Quinoline Derivatives as Novel Antimicrobial Agents Targeting Resistance Mechanisms

Previous Article in session

Antibiotic Resistance Genes in Aquaculture: Environmental Hotspots and Public Health Implications

Next Article in event

Potentiation of Antibacterial Activity of Cefixime in Synergy with Cirsium Arvense (L.)

Next Article in session

Third-generation Cephalosporin-resistant Escherichia coli Isolates Belonging to High-risk Clones Obtained From Fresh Pork Meat in La Plata City, Argentina

Multidrug-Resistant Klebsiella Pneumoniae in Native Portuguese Cattle Breeds: A Public Health Concern

Ricardo Faria

¹,

Rui Dantas

^{2, 3},

Luís Pinho

⁴,

^{2, 5, 6},

^{2, 7},

^{2, 8, 9, 10},

^{*

2, 11}

¹ University Institute of Health Sciences, CESPU, 4585-116 Gandra, Portugal
² UCIBIO—Applied Molecular Biosciences Unit, University Institute of Health Sciences (1H-TOXRUN, IUCS-CESPU), Avenida Central de Gandra 1317, 4585-116 Paredes, Portugal
³ ACRC—Associação Criadores da Raça Cachena, Parque Empresarial de Paçô, Rua da Roca 107, 4970-249 Arcos de Valdevez, Portugal
⁴ Department of Veterinary Clinics, Abel Salazar Biomedical Sciences Institute, University of Porto, Rua Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal
⁵ UCIBIO—Applied Molecular Biosciences Unit, Faculty of Pharmacy, University of Porto, Rua Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal
⁶ Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Rua Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal
⁷ CISAS–Center for Research and Development in Agrifood Systems and Sustainability, Polytechnic Institute of Viana do Castelo, NUTRIR (Technological Center for AgriFood Sustainability), Monte de Prado, 4960-320 Melgaço, Portugal
⁸ CIBIO—Research Center in Biodiversity and Genetic Resources, InBIO, Research Network in Biodiversity and Evolutionary Biology, Associated Laboratory, University of Porto, Campus de Vairão, Rua Padre Armando Quintas 7,4485-661 Vairão, Portugal
⁹ BIOPOLIS Program in Genomics, Biodiversity and Land Planning, Campus de Vairão, Rua Padre Armando Quintas 7, 4485-661 Vairão, Portugal
¹⁰ Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
¹¹ LAQV-REQUIMTE–Associated Laboratory for Green Chemistry, University NOVA of Lisbon, 1099-085 Caparica, Portugal

Academic Editor: Efstathios Giaouris

Published: 19 May 2025 by MDPI in The 4th International Electronic Conference on Antibiotics session Antibiotics and One Health

Abstract:

Introduction: The global increase in antibiotic-resistant bacteria, particularly multidrug-resistant strains, is diminishing antibiotic effectiveness. Livestock animals serve as reservoirs for these bacteria, threatening public health via the food chain and environmental contamination. Klebsiella pneumoniae is a significant pathogen, linked to fatal human infections, veterinary concerns, and multidrug resistance. This study aimed to phenotypically and genotypically characterize Klebsiella spp. isolated from fecal samples of four cattle breeds, Holstein–Friesian and three native Portuguese breeds—Barrosã, Cachena, and Minhota—in the Northern Region of Portugal.

Methods: A total of 640 fecal samples were collected from 40 farms, pooled by age group (8 calves and 8 cows per farm) and inoculated on MacConkey and HiCrome Klebsiella Selective agar. Klebsiella spp. isolates (43 out of 63) representing breeds/age groups were selected for antibiotic susceptibility testing (CLSI guidelines) and PCR assays for identification and detection of resistance genes.

Results: All 43 isolates were identified as Klebsiella pneumoniae and showed resistance to at least one antibiotic, with 100% of them being resistant to ampicillin. Barrosã and Cachena isolates displayed resistance only to ampicillin, while 17% (calves) and 13% (cows) of Minhota isolates demonstrated resistance to amoxicillin+clavulanic acid and tetracycline, respectively. Holstein-Friesian isolates exhibited resistance to multiple antibiotics, including amoxicillin+clavulanic acid (20%), cefotaxime (50%), aztreonam (30%), ciprofloxacin (20%), gentamicin (10%), tetracycline (80%), and trimethoprim+sulfamethoxazole (50%), all obtained from calves. Multidrug resistance was observed in 14% isolates, all from Holstein-Friesian cattle. ESBL activity was detected in 21% of the 43 K. pneumoniae isolates. From 42 tested isolates, the bla_SHV gene was detected in 67% of isolates, followed by sul2 (43%), aac(3′)-IV (43%), bla_TEM (33%), bla_CTX-M (14%), tetB (10%) and aac(6′)-Ib- cr (10%), with a higher prevalence in calves.

Conclusions: This work underscores, for the first time, the presence of multidrug-resistant K. pneumoniae in native Portuguese cattle breeds, highlighting potential risks to food safety and public health.

Acknowledgements: CoRECattle-GI2-CESPU-2022, EnteroGEN_GI2-CESPU_2023, FCT/MCTES-UIDB/50006/2020 and UIDP/50006/2020.

Keywords: Antimicrobial Resistance; Bovine; Klebsiella; native breeds

View Poster