Search Results (437)

Among synanthropic species, European hedgehogs are widely distributed throughout Europe. In recent decades, these animals have increasingly adapted to anthropogenic environments, where they find abundant shelter and food resources, along with fewer natural predators. As with other wildlife, it is likely that their coexistence in cities is also affecting their microbiota, promoting the development of antimicrobial resistance (AMR). This study aimed to assess the occurrence and patterns of AMR in commensal enteric Escherichia coli isolated from hedgehogs (n = 53) living in anthropogenic environments upon admission to a wildlife rescue center in Turin (Italy). The effects of hospitalization on the prevalence and trends of AMR were also assessed. Our results confirm that hedgehogs can harbor resistant E. coli upon admission, in particular against cefazolin (41.5%), ampicillin (37.7%), and enrofloxacin (22.6%). In addition, hospitalization promoted an increase in minimum inhibitory concentration (MIC) values of all antibiotics except imipenem, which led to a significant increase in E. coli that was resistant towards doxycycline, enrofloxacin, and trimethoprim-sulfamethoxazole. Admitted hedgehogs were also carriers of extended-spectrum beta-lactamase-producing E. coli (5.7%), whose presence increased during hospitalization (to 20.8%). These results highlight the role of hospitalizations longer than five days in the acquisition of AMR and suggest that European hedgehogs can become potential carriers of resistant E. coli following hospitalization. Full article

Background/Objective: This study aimed to evaluate the effectiveness of very early oral transition in Enterobacterales bloodstream infections (E-BSIs), identify factors associated with it, compare the effectiveness of different oral options, and assess its economic and ecological benefits. Methods: Retrospective, observational cohort study including monomicrobial E-BSI in clinically stable adult patients by day 3 of bacteremia with oral antibiotic options. Transition to oral antibiotics by day 3 or earlier (early oral (EO) group) was compared to later transition or remaining on intravenous therapy (nEO group). Early oral transition-associated factors were analyzed. Oral high-dose beta-lactams (BLs) were compared to quinolones (QLs) or trimethoprim/sulfamethoxazole (TS). Economic and ecological costs were assessed. Results: Of 345 E-BSI, 163 (47.2%) were in the EO group, characterized by more urinary tract infections (UTIs) and shorter hospital stays. The nEO group had higher Charlson Comorbidity Index (CCI), extended-spectrum beta-lactamase (ESBL) production, greater source control need, and longer time to clinical stability. There were no significant differences in mortality and relapse. UTIs were associated with early oral transition (OR 2.02, IC 95% 1.18–3.48), while higher CCI (0.85, 0.77–0.95), source control need (0.39, 0.19–0.85), longer time to clinical stability (0.51, 0.39–0.66), and ESBL isolates (0.39, 0.19–0.80) hindered this practice. High-dose BLs and QL/TS were equally effective. Early oral transition resulted in 38.794 KgCO₂eq reduction and EUR 269,557.99 savings. Conclusions: Very early oral transition at day 3 or before in stable E-BSI patients is effective, eco-sustainable, and cost-effective; UTI is related with the early oral switch, while comorbidities, ESBL production, source control need, or longer time to clinical stability hinder this practice. Full article

Background: Klebsiella variicola is a Gram-negative, capsulated, nonmotile, facultative anaerobic rod. It is one of the species belonging to the K. pneumoniae complex. The objective of this study was to gain insights into the antimicrobial resistance and virulence of K. variicola strains isolated from clinical samples from oncologic patients. Methods: Strain identification was performed using a mass spectrometry method. Whole genome sequencing was conducted for all analyzed strains. Antimicrobial susceptibility was determined using an automated method. The presence of antimicrobial resistance mechanisms and genes encoding extended-spectrum beta-lactamases (ESBL) was assessed using the double-disc synergy test and genotypic methods. Results: All isolates were identified as K. variicola using mass spectrometry and whole genome sequencing (WGS). All isolates were ESBL-positive, and two of them harbored the bla_CTX-M-15 gene. In our study, the bla_LEN-17 gene was detected in all strains. Genome sequence analysis of the K. variicola isolates revealed the presence of virulence factor genes, including entAB, fepC, ompA, ykgK, and yagWXYZ. Two different plasmids, IncFIB(K) and IncFII, were identified in all of the analyzed K. variicola strains. The detected virulence factors suggest the ability of the bacteria to survive in the environment and infect host cells. All isolates demonstrated in vitro susceptibility to carbapenems. Conclusions: Further studies are needed to confirm whether multidrug-resistant K. variicola strains represent an important pathogen in infections among oncologic patients. Full article

Introduction: Urinary tract infections (UTIs) remain a significant public health issue worldwide, particularly affecting the geriatric population with increased morbidity and mortality. Aging-related immune changes, comorbidities, and urogenital abnormalities contribute to the higher incidence and complexity of UTIs in elderly patients. Antimicrobial resistance, especially extended-spectrum beta-lactamase (ESBL) production and carbapenem resistance, poses a major challenge in managing UTIs in this group. Methods: This retrospective, multicenter study included 776 patients aged 65 and older, hospitalized with a diagnosis of urinary tract infection between January 2019 and August 2024. Clinical, laboratory, and microbiological data were collected and analyzed. Urine samples were obtained under sterile conditions and pathogens identified using conventional and automated systems. Antibiotic susceptibility testing was performed according to CLSI standards. Logistic regression analyses were conducted to identify factors associated with ESBL production, carbapenem resistance, and mortality. Results: Among the patients, the median age was 78.9 years, with 45.5% female. ESBL production was detected in 56.8% of E. coli isolates and carbapenem resistance in 1.2%. Klebsiella species exhibited higher carbapenem resistance (37.8%). Independent predictors of ESBL production included the presence of urogenital cancer and antibiotic use within the past three months. Carbapenem resistance was associated with recent hospitalization, absence of kidney stones, and infection with non-E. coli pathogens. Mortality was independently associated with intensive care admission at presentation, altered mental status, Gram-positive infections, and comorbidities such as chronic obstructive pulmonary disease and urinary incontinence. Discussion: Our findings suggest that urinary pathogens and resistance patterns in elderly patients are similar to those in younger adults reported in the literature, highlighting the need for age-specific awareness in empiric therapy. The identification of risk factors for multidrug-resistant organisms emphasizes the importance of targeted antibiotic stewardship, especially in high-risk geriatric populations. Multicenter data contribute to regional understanding of resistance trends, aiding clinicians in optimizing management strategies for elderly patients with UTIs. Conclusions: This study highlights that E. coli and Klebsiella species are the primary causes of UTIs in the elderly, with resistance patterns similar to those seen in younger adults. The findings also contribute important data on risk factors for ESBL production and carbapenem resistance, supported by a robust patient sample. Full article

Objectives: In the context of the global rise in antimicrobial resistance (AMR), this study aimed to investigate temporal trends in AMR among pathogens isolated from endometrial cultures of patients diagnosed with chronic endometritis (CE). Methods: This cross-sectional study included 244 women consecutively diagnosed with CE at the Gynecology Unit of the University of Bari, Italy, between January 2020 and June 2024. Exclusion criteria were (i) previous CE diagnosis or treatment; (ii) antimicrobial use in the month prior to hysteroscopy and biopsy; (iii) use of oral or vaginal prebiotics/probiotics or contraceptives in the three months prior; (iv) known immunosuppression; and (v) hypersensitivity to quinolones or macrolides. CE was diagnosed using hysteroscopy combined with endometrial histology and microbial culture. Specifically, in cases with hysteroscopic signs suggestive of CE, endometrial biopsies were obtained using a Novak curette and processed for histological and immunohistochemical analyses, as well as for microbial identification and antimicrobial susceptibility testing in accordance with EUCAST guidelines. The primary outcomes were the prevalence of CE-associated pathogens and their AMR profiles. Results: The median age at CE diagnosis was 33 years (range 26–44). The most frequently isolated pathogens were Enterococcus faecalis (26.2%), Escherichia coli (19.3%), and Ureaplasma urealyticum (16.4%). High AMR rates were observed, with increasing trends over time. Ampicillin resistance reached 98.5% (63/64), penicillin resistance 30.8% (16/52), and extended-spectrum beta-lactamase (ESBL) positivity 34.7% (25/72), all with statistically significant trends (p < 0.001). Resistance to commonly used first-line antimicrobials, such as tetracyclines, quinolones, and nitroimidazoles, was also substantial. Conclusions: This study highlights a significant increase in AMRs among microorganisms responsible for CE between 2020 and 2024. As a result, empirical first-line antimicrobial therapies commonly used to treat patients with CE may be increasingly ineffective in a growing number of cases. This underscores the need for improved and targeted diagnostic and therapeutic strategies to effectively manage CE and prevent treatment failures. Strengthening surveillance systems, implementing antimicrobial stewardship programs, and enhancing patient education may help counter the growing threat of AMR. Full article

Objectives: Significant differences in antibiotic resistance (AR) rates and multi-drug resistant (MDR) bacteria incidence exist in patients with acute cholangitis (AC) from different countries or regions. We aim to characterize and compare the microbial spectrum and AR patterns in patients with AC from two tertiary centers in Europe. Methods: We conducted a prospective, observational, multicentric study including patients diagnosed with AC and a positive bile culture, admitted to the Colentina Clinical Hospital (CCH), Bucharest, Romania, and the Haut-Lévêque Hospital (HLH), Bordeaux, France, between April 2022 and October 2023. Results: We included a total of 144 patients from the CCH with 190 positive bile cultures (31 patients had up to five episodes of AC during the study period) and 241 identified microbial strains, and 62 patients from the HLH with 67 positive bile cultures (5 patients had two episodes of AC) and 194 identified microbial strains. The most frequently isolated bacteria were Escherichia coli (30.70%) and Pseudomonas spp. (27.80%) in the CCH group, and Enterococcus faecalis (15.46%) and Escherichia coli (22/11.34%) in the HLH group. Furthermore, 51 (21.16%) of the strains identified in the CCH group and 15 (7.21%) in the HLH group were MDR, such as extended-spectrum beta-lactamase-producing Enterobacteriaceae or carbapenemase-producing Enterobacterales. The resistance rates for common antibiotics were 13.69% in the CCH group vs. 8.76% in the HLH group for ceftriaxone, 9.54% vs. 2.06% for meropenem, 16.59% vs. 6.70% for piperacillin/tazobactam, and 25.31% vs. 7.73% for levofloxacin. Conclusions: This comparative study shows significant differences between these countries in terms of the AR rates and MDR bacteria prevalence, highlighting the role of bile cultures as a safe and cost-effective method for guiding antibiotic treatment, thereby reducing the AR rates and complications. Full article

Background/Objectives: Antibiotic resistance is a significant and escalating challenge that limits available therapeutic options. This issue is further exacerbated by the decreasing number of new antibiotics being developed. Our study aims to describe the epidemiology and pattern of antibiotic resistance in Gram-negative infections isolated from a cohort of hospitalized patients and to analyze the distribution of infections within the hospital setting. Methods: A retrospective study was conducted on all patients admitted to Vito Fazzi Hospital in Lecce, Italy, who required an infectious disease consultation due to the isolation of Gram-negative bacteria from 1 January 2018 to 31 December 2022. Results: During the study period, 402 isolates obtained from 382 patients (240 men and 142 women) with infections caused by Gram-negative bacteria were identified. Among these isolated, 226 exhibited multidrug resistance, defined as resistance to at least one antimicrobial agent from three or more different classes. In 2018, the percentage of multidrug-resistant isolates peaked at 87.6%, before decreasing to the lowest level (66.2%) in 2021. Overall, of the 402 isolates, 154 (38.3%) displayed resistance to carbapenems, while 73 (18.1%) were resistant to extended-spectrum beta-lactamases (ESBLs). Among the resistant microorganisms, Klebsiella pneumoniae showed the highest resistance to carbapenems, accounting for 85.2% of all resistant strains. Escherichia coli exhibited the greatest resistance to ESBLs, with a rate of 86.7%. Among carbapenem-resistant K. pneumoniae isolates, the following resistance rates were observed: KPC-1 at 98.2%, IMP-1 at 0.9%, VIM-1 at 0.9%, and NDM-1 at 0.9%. Conclusions: Patients with infections caused by multidrug-resistant bacteria have limited treatment options and are therefore at an increased risk of death, complications, and longer hospital stays. Rapid diagnostic techniques and antimicrobial stewardship programs—especially for ESBLs and carbapenemases—can significantly shorten the time needed to identify the infection and initiate appropriate antimicrobial therapy compared to traditional methods. Additionally, enhancing surveillance of antimicrobial resistance within populations is crucial to address this emerging public health challenge. Full article

Neonatal sepsis is a major cause of morbidity and mortality in neonates. A particular concern is the increasing prevalence of antibiotic-resistant strains among neonatal intensive care units (NICUs). Two novel beta-lactam/beta-lactamase inhibitors have recently been approved for use in neonates with multidrug-resistant infections: ceftazidime/avibactam and ceftolozane/tazobactam. These agents demonstrate efficacy against a range of multidrug-resistant gram-negative pathogens, including extended-spectrum beta-lactamases (ESBL)-producing and carbapenem-resistant Enterobacterales, as well as multidrug-resistant Pseudomonas aeruginosa. This narrative review aims to summarize the current knowledge concerning the utilization of ceftazidime/avibactam and ceftolozane/tazobactam in the NICU. According to the existing literature, both agents have been shown to be highly effective with a favorable safety profile in the neonatal population. Full article

Background: Antimicrobial resistance (AMR) poses significant risks to human and animal health, while the environment can contribute to its spread. National AMR surveillance programs are pivotal for assessing AMR prevalence, trends, and intervention outcomes; however, integrating advanced surveillance tools can be difficult. This pilot study, conducted by FAO ECTAD Indonesia and DGLAHS, the Indonesian Ministry of Agriculture, evaluated the costs and benefits of integrating the Nanopore MinION, Illumina MiSeq, and Sensititre system into a culture-based slaughterhouse–river surveillance system. Methods: Water samples were collected from six chicken slaughterhouses and adjacent rivers (pre- and post-treatment effluent, upstream, and downstream). Culture-based ESBL and general E. coli concentrations were estimated via the WHO Tricycle Protocol, while isolates (n = 42) were sequenced (MinION, MiSeq) and antimicrobial susceptibility testing conducted (Sensititre). Results: The Tricycle Protocol results provided estimates of effluent and river concentrations of ESBL and general E. coli identifying ESBL-to-general E. coli ratios of 13.8% and 6.2%, respectively. Compared to hybrid sequencing assemblies, MinION had a higher concordance than MiSeq for ARG identification (98%), virulence genes (96%), and locations for both (predominately plasmids). Furthermore, MinION concordance with Sensititre AST was 91%. Conclusions: Cost–benefit comparisons suggest sequencing can complement culture-based methods but is dependent on the value placed on the additional information gained. Full article

Antibiotics are frequently used in the poultry industry, which has led to the emergence of bacterial strains that are resistant to antimicrobial treatments. The main objectives of this research were to conduct a multimodal risk assessment, to determine the extent of contamination of chicken meat with Escherichia coli, assess the prevalence of strains resistant to extended-spectrum cephalosporins (ESC), and characterise the genes associated with resistance and virulence. A standardised procedure involving enrichment in buffered peptone water and isolation of E. coli on MacConkey agar was carried out on 100 chicken carcasses. Subsequently, the sensitivity of the strains was tested against 21 antibiotic discs. Additionally, ESBL production was detected using a double synergy test. Specific PCRs were employed to identify resistance to critical antibiotics in human medicine (such as cephalosporins, carbapenems, fluoroquinolones, and colistin), as well as the presence of virulence genes. The contamination rate of chicken meat with E. coli was 82%. The prevalence of ESC-resistant isolates was 91.2%. Furthermore, 76.5% of the isolates exhibited ESBL production, with the different beta-lactamase genes (bla_CTXM, bla_TEM, and bla_SHV). The mcr-1 gene, associated with colistin resistance, was detected in four strains (5.9%). Some isolates also carried resistance genes such as sul1, sul2, sul3, tetA, tetB, qnrB, and qnrS. In addition, several virulence genes were detected. In our study, we were able to link the expression of AMR to the iron metabolic regulatory elements using a multimodal machine learning approach; this mechanism could be targeted to mitigate the bacteria virulence and resistance. The high prevalence of ESBL-producing and multi-resistant E. coli strains in poultry presents significant human health risks, with the focus on antibiotic-resistant uropathogenic strains since poultry meat could be an important source of uropathogenic strains, underscoring the danger of hard-to-treat urinary tract infections, stressing the need for controlled antibiotic use and thorough monitoring. Full article

Background: Urinary tract infections (UTIs) caused by the multidrug resistance (MDR) phenotype termed extended-spectrum beta lactamase (ESBL)-producing E. coli is a significant and growing global health concern. In response to the rising prevalence, the novel Beta Lactam-Beta Lactamase inhibitor (BL/BLI) combinations have been introduced in recent years. While these agents have shown efficacy, their clinical utility is constrained by high cost, limited availability, and emerging resistance mechanisms. The rational of this study was to test the in vitro activity of a cost-effective alternative to currently available BL–BLI combinations against ESBL-producing E. coli isolated from urinary tract infections (UTIs). Objective: This study investigates the in vitro antimicrobial activity of cefaclor (CFC), both as monotherapy and in combination with the β-lactamase inhibitors clavulanic acid (CA) and sulbactam (SUL), against 52 ESBL-producing E. coli isolates derived from urine cultures of patients diagnosed with UTIs. Methods: The susceptibility ranges were measured by disk diffusion and minimal inhibitory concentration (MIC) methods. In addition, the Time kill assay and disk approximation method were performed to measure the synergistic and bactericidal activity of the approached combination. Results: The MIC50 and MIC90 for CFC were improved from more than 128 µg/mL to 8/4 µg/mL when CFC was combined with either CA or SUL. The triple combination format of CFC/CA/SUL showed MIC50 and MIC90 values at 8/4/4 µg/mL and 64/32/32 µg/mL, respectively. The recovered susceptibility percentages were 54%, 54%, and 58% for CFC/CA, CFC/SUL, and CFC/CA/SUL combinations, respectively. Disk approximation and time–kill assay results revealed synergy and bactericidal effects when CFC combined with CA or SUL for isolates that showed susceptibility restorations of CFC when coupled with CA or SUL by the disk diffusion and MIC method. Conclusions: This study proposes a cost-effective combination that could mitigate resistance development and offer a sparing option to last resort treatment choices including carbapenems. However, testing efficacy in a clinical setting is crucial. Full article

Acute diarrhoeal disease caused by antibiotic-resistant diarrhoeagenic bacteria is a significant global public health issue, particularly in low- and middle-income countries. This study provides the first molecular characterisation of antimicrobial resistance profiles, including the detection of CTX-M-15 and CTX-M-55 extended-spectrum beta-lactamases (ESBLs), among diarrhoeagenic Enterobacterales in Bioko Island, Equatorial Guinea, offering novel epidemiological insights into an understudied region. This study investigated the antibiotic resistance profiles of pathogenic bacteria isolated from diarrhoeal samples on Bioko Island. A total of 153 clinical isolates were collected between 1 February and 30 May 2014, and antimicrobial susceptibility testing was performed at Loeri Comba Polyclinic (Malabo) using the Kirby–Bauer method. The molecular characterisation of β-lactamase-associated genes was performed on different isolates of diarrhoeagenic pathotypes—144 Escherichia coli, 7 Salmonella enterica, and 2 Shigella flexneri—at the National Centre for Microbiology (Majadahonda, Spain). High resistance rates were detected against ampicillin (98%), tetracycline (93.5%), sulfonamides (94.8%), sulfamethoxazole–trimethoprim (88.2%), and cefotaxime (78.8%), while moderate rates of resistance were noted for ciprofloxacin (26.7%), and all isolates remained susceptible to imipenem. Of the isolates, 107 (69.9%) produced either single or multiple β-lactamases. Among these, 73 (68.2%) harbored classical β-lactamases, specifically TEM and OXA-1 types, representing 47.7% of the total sample. Additionally, 34 (31.8%) of the isolates were identified as producers of extended-spectrum β-lactamases (ESBLs), specifically CTX-M enzymes. Sequencing identified CTX-M-15 and CTX-M-55 variants. The predominant ESBL-producing bacteria were enteroaggregative Escherichia coli (56.2%), followed by enteropathogenic and enterotoxigenic E. coli. These findings confirm the circulation of multidrug-resistant diarrhoeagenic Enterobacterales in Equatorial Guinea, raising concerns about limited treatment options due to widespread resistance to multiple antibiotic classes, including third-generation cephalosporins and quinolones. The most important conclusion drawn from this study is that a high percentage of diarrhoeagenic bacteria have an antibiotic resistance and multi-resistance profile, especially to beta-lactams and other groups of antibiotics such as tetracyclines and sulphonamides. There is also a moderate prevalence of isolates carrying ESBLs on Bioko Island, Equatorial Guinea, which could indicate the inappropriate use of antimicrobials. Full article

The emergence and dissemination of antibiotic-resistant Klebsiella pneumoniae, particularly those are extended-spectrum beta-lactamase (ESBL) producers, thought to pose a serious threat to global health. This study aimed to isolate and identify the ESBL-producing K. pneumoniae from captive wild and migratory birds in Bangladesh along with their antimicrobial resistance characteristics. In this investigation, standard bacteriological methods were used to detect K. pneumoniae in 219 fecal samples. The positive isolates were confirmed by PCR and antibiotic susceptibility testing was performed by disk diffusion method. K. pneumoniae was detected in 93 (42.47%, 95% CI: 35.8–49.3) out of 219 fecal samples. The prevalence of K. pneumoniae was higher in captive wild birds (50%; 40/80) compared to migratory birds (38.1%; 53/139). The isolates showed high resistance to ampicillin (69.9%) and streptomycin (64.5%). Conversely, the highest sensitivity was recorded for trimethoprim-sulfamethoxazole (84.95%), followed by levofloxacin (79.57%) and gentamicin (69.89%). Molecular screening revealed that all positive isolates harbored bla_TEM-1&2 encoding genes, with 45.2% and 15.1% carried bla_SHV-1 and bla_OXA-1,4&30, respectively. Additionally, resistance genes strA (30.1%), tetA (9.7%), and sul1 (9.7%) were detected. The Multiple Antibiotic Resistance (MAR) index ranged from 0.18 to 0.64, with 63.4% of isolates classified as MDR. The isolation of MDR and ESBL producing K. pneumoniae from captive wild and migratory birds suggests that these birds may serve as reservoirs for the spread of these bacteria, potentially impacting public health in the study region. Full article

Background/Objectives: The widespread use of antibiotics in animal husbandry has led to an increase in antimicrobial-resistant Escherichia coli, particularly strains producing extended-spectrum β-lactamases (ESBL) and AmpC β-lactamases. This study aimed to isolate and characterize such strains from fecal samples of broiler chickens (n = 71) and slaughtered turkeys (n = 31) in northwestern Romania. Methods: Antimicrobial susceptibility testing and PCR were used to evaluate phenotypic resistance patterns and detect the presence of resistance genes (AmpC, blaZ, and blaTEM). Results: The results showed that 55% of turkey and 61% of broiler isolates were presumptive ESBL/AmpC producers. Among all isolates, 50% were classified as extensively drug-resistant (XDR), 44% as multidrug-resistant (MDR), and only 6% were fully susceptible. Gene detection revealed an overall prevalence of 44.2% for AmpC, 72.7% for blaZ, and 58.1% for blaTEM, yielding a total penetrance of 51.09%. The diagnostic odds ratio (DOR) values, ranging from 0.67 to 81, suggest the efficacy of the antibiotic susceptibility testing method used in detecting the presence of these resistance genes. Conclusion: Overall, these findings highlight a significant burden of antimicrobial-resistant, poultry-associated E. coli strains, warranting stricter antimicrobial stewardship. Full article

Gram-negative enteric rods (GNERs) are transient members of the oral microbiota and are considered a superinfection in patients with periodontitis that poses local and systemic risks due to associations with infections and multidrug resistance, including extended-spectrum beta-lactamases. These pathogens often resist antibiotics such as amoxicillin, doxycycline, and ciprofloxacin, complicating dental treatments. Though their resistance patterns vary, links between specific resistance genes and phenotypic resistance remain unclear. Objectives: To determine the correlation between resistance genes (blaTEM, blaSHV, tetQ, tetM, qnrB, qnrS, and mph(A)) and phenotypic resistance in GNERs isolated from oral cavity samples. Methods: A total of 90 oral isolates of GNERs were isolated from patients in a dental clinic, and bacteria were identified by the BD BBL Crystal biochemical panel. The antibiotic susceptibility testing was conducted through broth microdilution following CLSI standards for drives such as amoxicillin, amoxicillin/clavulanic acid, doxycycline, ciprofloxacin, and azithromycin. Resistance genes, including blaTEM, blaSHV, tetQ, tetM, qnrS, qnrB, and mph(A), were detected using polymerase chain reaction and gel electrophoresis. The proportions of species, resistance genes, and minimum inhibitory concentration values were statistically analyzed. Conclusions: As expected, most enteric bacteria showed natural resistance to beta-lactams. Significant resistance to azithromycin was observed in some species. Genotypic and phenotypic profiles suggest the existence of alternative resistance mechanisms; therefore, other mechanisms associated with antibiotic resistance should be investigated. Full article