Antimicrobial Susceptibility Profiles Research Articles

Methicillin‐resistant Staphylococcus aureus enterotoxin producers, isolated from the production chain of artisanal Coalho cheese

This study aimed to evaluate the presence of Staphylococcus aureus from the production chain of artisanal Coalho cheese, and to analyse the phenotypic profile of the strains, virulence factors and antimicrobial susceptibility profile. From the 52 samples collected, typical colonies of Staphylococcus spp. were isolated. From these positive S. aureus isolates, the genes encoding for enterotoxin production and antibiotic resistance were characterised. Additionally, agr locus typing was also performed. A significant presence of the sea enterotoxin producing gene, a higher incidence of the mecA gene and agr III group was identified. There was multiple resistance to penicillin, oxacillin, erythromycin and clindamycin in 79% of isolates. These results indicate that the artisanal Coalho cheese production process is associated with high contamination levels and significant potential for the isolated strains to produce enterotoxins. Therefore, there is cause for concern regarding the quality of the artisanal Coalho cheese produced.

Bullet-related bacterial wound infections among injured personnel at emergency site hospitals in Bahir Dar: prevalence, antimicrobial susceptibility and associated factors.

Bullet-related bacterial wound infection can be caused by high-velocity bullets and shrapnel injuries. In Ethiopia, significant injuries were reported that may cause severe wound infections, persistent systemic infections and may lead to amputation and mortality. The magnitude, antimicrobial susceptibility profiles, and factors associated with bacterial wound infections among patients with bullet-related injuries are not yet studied particularly at health facilities in Bahir Dar, Northwest Ethiopia. Therefore, this study was aimed to determine the prevalence, bacterial profiles, antimicrobial susceptibility profiles, and factors associated with bacterial infections among patients with bullet-related injuries at referral health facilities in Bahir Dar, Northwest Ethiopia. A Hospital-based cross-sectional study was conducted among patients with bullet-related injuries at three referral health facilities in Bahir Dar from May 25 to July 27, 2022. A total of 384 patients with bullet-related injuries were included in the study. Sociodemographic and clinical data were collected using a structured questionnaire. Wound swabs were collected aseptically and cultured on Blood and MacConkey agar following bacteriological standards. Biochemical tests were performed to differentiate bacteria for positive cultivation and antimicrobial susceptibility profiles of the isolates were done on Muller Hinton agar using the Kirby-Bauer disk diffusion technique according to the 2021 Clinical Laboratory Standard Institute (CLSI) guideline. The data were entered using Epi-Info version 7.3 and analyzed using SPSS version 25. Descriptive data were presented using frequency, percentages, figures, and charts. Logistic regression was carried out to identify factors associated with bacterial wound infections. P-value < 0.05 was considered statistically significant. The prevalence of bullet-related bacterial wound infection among three referral hospitals in Bahir Dar city was 54.7%. The most commonly isolated Gram-negative organism was Klebsiella spps 49 (23.3%) while among Gram-positive organism, Staphylococcus aureus 58 (27.6%) and coagulase-negative staphylococci (CONS) 18 (8.6%). Contamination, hospitalization and smoking habit were significantly associated with the presence of bullet-related bacterial wound infections. Over 97% multidrug resistant (MDR) bacterial isolates were identified and of theses, E. coli, Proteus species, Citrobactor, and Staphylococcus aureus were highly drug resistant. Increased prevalence of bullet-related bacterial wound infection was noticed in this study. S. aureus followed by Klebsiella species were most commonly isolated bacteria. High frequency of resistance to Ampicillin, Oxacillin, Cefepime, Ceftriaxone, Ceftazidime, Vancomycin, and Norfloxacin was observed. Therefore, proper handling of bullet injuries, prompt investigation of bacterial infections, monitoring of drug sensitivity patterns and antibiotic usage are critical.

Molecular diversity and antimicrobial susceptibility profile of Vibrio species and distribution of other bacteria isolated from water Hyacinth (Eichornia crassipes) and Lagos lagoon

Molecular diversity and antimicrobial susceptibility profile of Vibrio species and distribution of other bacteria isolated from water Hyacinth (Eichornia crassipes) and Lagos lagoon

Multidrug-resistant Escherichia coli strains isolated from swine manure biofertilizer in Brazil.

Escherichia coli is one of the key bacteria responsible for a variety of diseases in humans and livestock-associated infections around the globe. It is the leading cause of mortality in neonatal and weaned piglets in pig husbandry, causing diarrhea and significant harm to the industry. Furthermore, the frequent and intensive use of antimicrobials for the prevention of diseases, particularly gastrointestinal diseases, may promote the selection of multidrug-resistant (MDR) strains. These resistant genotypes can be transmitted through the excrement of animals, including swine. It is common practice to use porcine manure processed by biodigesters as fertilizer. This study aimed to examine the antimicrobial susceptibility, the presence of virulence genes frequently associated with pathotypes of intestinal pathogenic E. coli (InPEC), and antimicrobial resistance genes (ARGs) of 28 E. coli isolates collected from swine manure fertilizers. In addition, the enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) technique was used to investigate the genetic relationship among the strains. Using disk diffusion, the antimicrobial susceptibility profiles of the strains were determined. Using polymerase chain reaction (PCR), 14 distinct virulence genes associated with the most prevalent diarrhea and intestinal pathogenic E. coli (DEC/InPEC) and five ARGs were analyzed. All isolates tested positive for multidrug resistance. There was no detection of any of the 14 virulence genes associated with InPECs, indicating the presence of an avirulent commensal microbiota. Molecular classification by ERIC-PCR revealed that the majority of isolates (27 isolates) coalesced into a larger cluster with a genetic similarity of 47.7%; only one strain did not cluster in this cluster, indicating a high level of genetic diversity among the analyzed isolates. Thus, it is of the utmost importance to conduct epidemiological surveillance of animal breeding facilities in order to determine their microbiota and formulate plans to reduce the use of antimicrobials and improve animal welfare.

Epidemiology, pathogenicity, risk factors, and management of Helicobacter pylori infection in Saudi Arabia.

Helicobacter pylori (H. pylori) is a gastric microbial pathogen that infects approximately half of the global population. This bacterium significantly contributes to various gastroduodenal diseases, including chronic active gastritis, peptic ulcerations, and malignant transformations. This review focuses on epidemiology, pathogenicity, virulence genes, risk factors, and management of H. pylori infection, specifically within the context of Saudi Arabia. The results presented here are grounded in studies conducted in Saudi Arabia, contrasting with mere bibliographic reviews of findings from other countries. H. pylori infection has been observed in Saudi Arabia, with substantial differences in the prevalence, ranging between 10-96% among various studied populations. Several risk factors for H. pylori infection have been identified, encompassing socioeconomic status, medical history, personal hygiene, and behavioral practices. Among the virulence genes harbored by H. pylori, cytotoxin-associated gene A (cagA) and vacuolating cytotoxin (vacA) are most common, with their presence correlating with the pathogenicity and clinical manifestations of the associated diseases. A range of invasive and non-invasive diagnostic assays have been utilized to identify H. pylori infection, with their employment being influenced by factors like availability, cost, patient age, gastric symptoms, and the specifics of clinical information sought. While detection methods like the H. pylori stool antigen test and the urea breath test offer more accuracy and speed, culturing remains indispensable for determining the antimicrobial susceptibility profile. The emergence of resistant strains across varying regional settings poses a significant challenge to treatment endeavors, necessitating an assessment of local antimicrobial resistance rates prior to formulating treatment strategies. The findings of this review highlight the importance of continuous implementation of screening, control, and prevention of H. pylori infection to combat the spreading infection and other related complications.

Clinical characteristics and antimicrobial susceptibility profiles of Mycobacterium abscessus and Mycobacterium massiliense pulmonary infection

IntroductionMycobacterium abscessus complex (MABC) is the most common rapidly growing Mycobacterium species in structural pulmonary diseases and can be life-threatening. This study aimed to assess the clinical characteristics and drug susceptibility statuses of different Mycobacterium abscessus (MAB) subspecies. MethodsDNA sequencing was used to differentiate clinical MABC subspecies isolates. The Clinical and Laboratory Standards Institute guidelines were used to determine vitro susceptibility of imipenem-relebactam, omadacycline, and other conventional antibiotics. Patient's clinical characteristics were collected and analysed. ResultsThere were 139 M. abscessus, 39 M. massiliense, and 1 M. bolletii, accounting for 77.7%, 21.8%, and 0.5% of the MABC isolates, respectively. Patients with M. abscessus pulmonary disease (M.ab-PD) had higher proportions of older adults, tuberculosis history, chronic pulmonary disease, and malignancy than those with M. massiliense pulmonary disease (M.ma-PD). Patients with M.ab-PD had higher rates of bilateral middle- and lower-lobe involvement than patients with M.ma-PD. Both subspecies showed high resistance rates to doxycycline and moxifloxacin, and clarithromycin-induced resistance was more common in M.ab than in M.ma. Relebactam with imipenem resulted in a 2-fold reduction in the minimum inhibitory concentration (MIC) value compared to imipenem alone among MAB; furthermore, the MIC was lower in M.ab than in M.ma. Omadacycline and tigecycline had comparable in vitro susceptibility, and the MIC showed no statistically significant difference between M.ab and M.ma. ConclusionsM.ab is the most prevalent MABC subspecies in the Zhejiang Province. Patients with M.ab-PD have complex underlying diseases and broader lobar lesions. Imipenem-relebactam and omadacycline are promising antibiotics for MABC infection treatment.

Prevalence of Methicillin-Resistant Staphylococcus Aureus and Antibiotic Residue in Pasteurized and Raw Farm Milk in Tehran

Background: There is a global threat of methicillin-resistant Staphylococcus aureus (S. aureus or MRSA), which has been regarded as a priority pathogen by the world health organization (WHO). Livestock and its products are the sources of MRSA which can often occur in poor breeding conditions. The present study aims to investigate the prevalence of MRSA and the rate of antibiotic residue in pasteurized and raw farm milk. Methods: This was a cross-sectional study conducted from April to July 2020. 250 samples (200 samples of raw milk in farms around Tehran and 50 samples of pasteurized milk) were cultured to evaluate the occurrence of S. aureus and its antimicrobial susceptibility profile to 7 antimicrobial panels. Hansen Kit was used to monitor antibiotic residue in milk. Results: 63 S. aureus isolates (25.2%) were detected from 250 milk samples. Among 200 raw milk samples, 48 (24%) S. aureus isolates were detected and no strain of S. aureus was isolated from pasteurized milk. The highest rates of resistance belonged to ampicillin (95.8%), amoxicillin/clavulanic acid (87.5%), tetracycline (50%), and cefoxitin (45.8%). Moreover, 43 (17.2%) out of 250 milk samples had antibiotic residue in the antibiotic residue test using Danish Hansen kit. Conclusion: The present study indicates a high prevalence of subclinical S. aureus in dairy herds in Tehran, Iran. The milk contaminated with S. aureus and MRSA, posed a risk to public health owing to the presence of a phenotype resistant to very common antibiotics.

Molecular detection of enterotoxins in multidrug resistant Aeromonas from ready to eat foods in North Western Himalayas: public health significance

Aeromonas spp. are normal inhabitants of aquatic environments and are emerging foodborne bacterial pathogens. Aeromonas spp. contamination is frequent in ready-to-eat (RTE) seafood and can also occur in products prepared from milk or meat. The study determined the enterotoxin and antimicrobial susceptibility profiles of Aeromonas spp. isolates recovered from RTE milk products (n=105), RTE meat/fish products (n=40) and drinking water (n=60) samples collected from tourist places in Himachal Pradesh, India, in northwestern Himalayas. 7.3% (16/220) samples were found contaminated with Aeromonas spp. These isolates were identified as A. hydrophila (31.3%), A. schubertii (25.0%), A. sobria (25.0%) and A. veronii (18.8%). Aeromonas spp. contamination was significantly higher (14.3%, 15/105, p=0.0001) in RTE milk products. The contamination levels for water samples were 1.7% whereas none of the tested RTE meat or fish products yielded Aeromonas spp. Among RTE milk products, contamination was significantly higher in paneer (South Asian soft cheese) (26.1%, p=0.0027) and cream (25.0%, p=0.046) based RTE foods. All isolates carried alt (361 bp), encoding a cytotonic heat-labile enterotoxin. Ampicillin resistance was 100% and high levels (>30%) of resistance were recorded for amoxicillin/clavulanic acid, amikacin, cefotaxime and ceftazidime. Six (37.5%) isolates were multi drug resistant (MDR), showing resistance to aminoglycosides, cephams and penicillins. Isolation of alt carrying MDR isolates from RTE foods indicates that Aeromonas spp. can be potential foodborne public health threat in northwestern Himalayas.

Escherichia coli isolated from pyometra and cystitis in the same animal exhibit a wide phenotypic similarity.

Pyometra and cystitis caused by Escherichia coli are common diseases identified in canine or feline females. The origin of pyometra infection remains uncertain, and effective prevention strategies for this disease are still unknown. This study aimed to provide a phenotypic characterisation, including antimicrobial resistance and virulence profiles, of Endometrial Pathogenic (EnPEC) and Uropathogenic (UPEC) E. coli strains isolated simultaneously from the same animal. Sixteen E. coli strains, from eight different animals, were analysed in this study. The antimicrobial susceptibility profile of EnPEC and UPEC strains was determined using the disc diffusion method, which showed a similar susceptibility profile among strains (EnPEC and UPEC) from the same animal. The virulence profile of the strains was assessed through biofilm formation, as well as serum resistance abilities. EnPEC and UPEC strains from the same animal exhibited slight variations in their virulence and antimicrobial resistance capabilities. Overall, most of the strain pairs showed a high similarity in their ability to establish biofilms and survive in serum complement activity. Overall, strains of E. coli isolated from both pyometra and cystitis in the same animal, despite presenting distinct clinical diseases, exhibit a wide phenotypic similarity, suggesting a common origin for the strains.

Antimicrobial Susceptibility Profiles of Pasteurella multocida Isolates from Clinical Cases of Waterfowl in Hungary between 2022 and 2023

The waterfowl industry represents a narrow, yet economically significant, sector within the poultry industry. Although less prominent, the waterfowl sector is nonetheless of equal importance to any other livestock sector in terms of antimicrobial resistance and animal health issues. This study assesses the antimicrobial resistance profile of Pasteurella multocida bacterial strains isolated from clinical cases in Hungary’s duck and goose populations, determining the minimal inhibitory concentration (MIC) of 27 samples collected from 15 different locations. The results indicate that the isolated strains were susceptible to most antibiotics, except for notable resistance to enrofloxacin. These findings support that Pasteurella multocida largely retained its susceptibility. However, the observed resistance to enrofloxacin suggests overuse of fluoroquinolones, which indicates the potential need for stricter regulation of their use in the poultry industry.

Prevalence and Antimicrobial Susceptibility Profile of Salmonella from Poultry Farms and In-Contact Humans and Associated Risk Factors in Addis Ababa, Ethiopia.

Poultry and poultry products are the common sources of Salmonella,which is one of the serious food-borne bacterial diseases in humans. Little is known about the status of Salmonella and their antimicrobial susceptibility in poultry farms in Addis Ababa. This study was conducted to estimate the prevalence and antimicrobial susceptibility of Salmonella isolates and to investigate possible risk factors for the occurrence of Salmonella in poultry farms in Addis Ababa. We recruited 58 poultry farms, from which 471 poultry-related samples and 44 stool samples from in-contact humans were collected. The isolates were tested for their susceptibility to 11 antimicrobials using the Kirby-Bauer disk diffusion assay. The farm-level prevalence of Salmonella was 36.2% and the sample-level prevalence was 6.4% for samples taken from poultry farms and 4.5% in human stool samples who have contact with poultry. On-farm waste disposal practices and chicken being purchased from different multiplication farms were significantly associated with Salmonella positivity of the farms (p < 0.05). Eleven (34.4%) Salmonella isolates were resistant to streptomycin, and nine (28.1%) were resistant to tetracycline. Thirteen (40.6%) Salmonella isolates were resistant to two or more antimicrobials tested in this study, whereas resistance to 3 or more antimicrobials was detected in seven (21.9%) isolates. In conclusion, a high prevalence of Salmonella and a high rate of resistance to multiple antimicrobials were detected in poultry farms in Addis Ababa. Hence, implementation of strong biosecurity measures and rational use of antimicrobials are recommended.

Co-resistance to methicillin and clindamycin among coagulase-negative staphylococci isolates recovered from pet food in Brazil

Pet food have been considered as possible vehicles of bacterial pathogens. The sudden boom of the pet food industry due to the worldwide increase in companion animal ownership calls for pet food investigations. Herein, this study aimed to determine the frequency, antimicrobial susceptibility profile, and molecular characteristics of coagulase-negative staphylococci (CoNS) in different pet food brands in Brazil. Eighty-six pet food packages were screened for CoNS. All isolates were identified at species level by MALDI-TOF MS and species-specific PCR. Antimicrobial susceptibility testing was performed by disc diffusion and broth microdilution (vancomycin and teicoplanin only) methods. The D-test was used to screen for inducible clindamycin phenotype (MLS-B). SCCmec typing and detection of mecA, vanA, vanB, and virulence-encoding genes were done by PCR. A total of 16 (18.6 %) CoNS isolates were recovered from pet food samples. Isolates were generally multidrug-resistant (MDR). All isolates were completely resistant (100 %) to penicillin. Resistances (12.5 % - 75 %) were also observed for fluoroquinolones, sulfamethoxazole-trimethoprim, tetracycline, rifampicin, erythromycin, and tobramycin. Isolates were susceptible to vancomycin (MICs <0.25–1 μg/mL) and teicoplanin (MICs <0.25–4 μg/mL). Intriguingly, 3/8 (37.5 %) CoNS isolates with the ERYRCLIS antibiotype expressed MLS-B phenotype. All isolates harboured blaZ gene. Seven (43.8 %) isolates carried mecA; and among them, the SCCmec Type III was the most frequent (n = 5/7; 71.4 %). Isolates also harboured seb, see, seg, sej, sem, etb, tsst, pvl, and hla toxin virulence-encoding genes (6.3 % - 25 %). A total of 12/16 (75 %) isolates were biofilm producers, while the icaAB gene was detected in an S. pasteuri isolate. Herein, it is shown that pet food is a potential source of clinically important Gram-positive bacterial pathogens. To the best of our knowledge, this is the first report of MLS-B phenotype and MR-CoNS in pet food in Latin America.

Antimicrobial Susceptibility Profiles of Klebsiella pneumoniae Strains Collected from Clinical Samples in a Hospital in Southern Italy.

Infections caused by antibiotic-resistant bacteria represent a serious threat to global public health. Recently, due to its increased resistance to carbapenems and β-lactams, Klebsiella pneumoniae has become one of the main causes of septicemia, pneumonia, and urinary tract infections. It is crucial to take immediate action and implement effective measures to prevent further spread of this issue. This study aims to report the prevalence and antibiotic resistance rates of K. pneumoniae strains isolated from clinical specimens from 2015 to 2020 at the University Hospital of Salerno, Italy. More than 3,800 isolates were collected from urine cultures, blood cultures, respiratory samples, and others. K. pneumoniae isolates showed broad resistance to penicillin and cephalosporins, and increased susceptibility to fosfomycin and gentamicin. Extended spectrum beta-lactamase (ESBL) isolates accounted for 20-22%. A high percentage of strains tested were resistant to carbapenems, with an average of 40% to meropenem and 44% to ertapenem. The production of ESBLs and resistance to carbapenems is one of the major public health problems. Constant monitoring of drug-resistant isolates is crucial for developing practical approaches in implementing antimicrobial therapy and reducing the spread of K. pneumoniae in nosocomial environments.

Occurrence, antibiotic resistance profiles and associated risk factors of Klebsiella pneumoniae in poultry farms in selected districts of Somalia Reginal State, Ethiopia

BackgroundKlebsiella pneumoniae is an opportunistic infection that causes production losses and death in the chicken industry. A cross-sectional study was conducted on exotic chicken breeds reared at the Jigjiga poultry farm from November 2022 to May 2023 to estimate the occurrence, associated risk factors, and antimicrobial susceptibility profiles of Klebsiella pneumoniae. The chickens were selected using systematic random sampling techniques. A total of 384 cloacal swabs were collected aseptically and transported to the laboratory for analysis. For statistical analysis, STATA® version 14.0 statistical software was used.ResultsFrom 384 examined faecal samples, 258 (67.2%) prevalences of Klebsiella pneumoniae were found. Furthermore, the association of the study’s risk factors with the prevalence of Klebsiella pneumoniae was explored, and no statistically significant association was identified between sex and age. Nonetheless, relative prevalence at the age level was higher in chickens aged 12 months (67.6%) and Sasso breeds (90.0%). Similarly, male chickens and those raised for meat and egg production had a high prevalence rate of 72.5 and 75.8%, respectively. A total of 30 isolated Klebsiella pneumoniae colonies were tested in vitro for antibiotic sensitivity for six drugs, and it was shown that Klebsiella pneumoniae is moderately sensitive to Penicillin G (43.3%) while having higher resistance to Oxytetracycline (80.0%).ConclusionsThe current findings revealed that the research area had the highest prevalence of Klebsiella pneumoniae, and the isolates were resistant to commonly used drugs in the study area. Thus, a long-term intervention plan, thorough research to determine a nationwide status, as well as further multi-drug resistance patterns and molecular characterization, were urged.

Occurrence, antimicrobial susceptibility, and resistance genes of Staphylococcus aureus in milk and milk products in the Arsi highlands of Ethiopia.

In Ethiopia, milk production and handling practices often lack proper hygiene measures, leading to the potential contamination of milk and milk products with Staphylococcus aureus (S. aureus), including methicillin-resistant strains,posing significant public health concerns. This study aimed to investigate the occurrence, antimicrobial susceptibility profiles and presence of resistance genes in S. aureus strains isolated from milk and milk products. A cross-sectional study was conducted in the Arsi highlands, Oromia, Ethiopia from March 2022 to February 2023. A total of 503 milk and milk product samples were collected, comprising 259 raw milk, 219 cottage cheese, and 25 traditional yogurt samples. S. aureus isolation and coagulase-positive staphylococci enumeration were performed using Baird-Parker agar supplemented with tellurite and egg yolk. S. aureus was further characterized based on colony morphology, Gram stain, mannitol fermentation, catalase test, and coagulase test. Phenotypic antimicrobial resistance was assessed using the Kirby-Bauer disc diffusion method, while the polymerase chain reaction (PCR) was employed for confirming the presence of S. aureus and detecting antimicrobial resistance genes. S. aureus was detected in 24.9% of the milk and milk products, with the highest occurrence in raw milk (40.9%), followed by yogurt (20%), and cottage cheese (6.4%). The geometric mean for coagulase-positive staphylococci counts in raw milk, yogurt, and cottage cheese was 4.6, 3.8, and 3.2 log10 CFU/mL, respectively. Antimicrobial resistance analysis revealed high levels of resistance to ampicillin (89.7%) and penicillin G (87.2%), with 71.8% of the isolates demonstrating multidrug resistance. Of the 16 S. aureus isolates analyzed using PCR, all were found to carry the nuc gene, with the mecA and blaZ genes detected in 50% of these isolates each. This study revealed the widespread distribution of S. aureus in milk and milk products in the Arsi highlands of Ethiopia. The isolates displayed high resistance to ampicillin and penicillin, with a concerning level of multidrug resistance. The detection of the mecA and blaZ genes in selected isolates is of particular concern, highlighting a potential public health hazard and posing a challenge to effective antimicrobial treatment. These findings highlight the urgent need to enhance hygiene standards in milk and milk product handling and promote the rational use of antimicrobial drugs. Provision of adequate training for all individuals involved in the dairy sector can help minimize contamination. These measures are crucial in addressing the threats posed by S. aureus, including methicillin-resistant strains, and ensuring the safety of milk and its products for consumers.

The microbiological profile of necrotising fasciitis at a secondary level hospital in Gauteng.

Necrotising fasciitis (NF) is a fulminant soft tissue infection that requires timely diagnosis, urgent surgical debridement, and appropriate antimicrobial therapy. The choice of empiric antimicrobial therapy depends on the microorganisms cultured and the antimicrobial resistance profile of the institution. Necrotising fasciitis has not been studied in our setting. The aim of the study was to audit the microbiological profile of NF and antimicrobial susceptibility profile. This was a retrospective study in a secondary level hospital from the period of 2014-2020. The patients' demographic data, clinical features, location of infection, comorbidities, laboratory and microbiological profiles were analysed. There were 53 patients during 2014-2020 with median age of 45.5 (38.5-56.0) years. The majority of the patients were males (35 [66.04%]), had no comorbidities (25 [47.17%]), and the lower limb was the most common anatomic site (17 [32.08%]). Type II (monomicrobial) NF was the predominant type (31 [58.49%]). Staphylococcus aureus was the most prevalent Gram-positive bacteria (18 [38%]) and Escherichia coli, the main species isolated in the Gram-negative bacteria (14 [36%]) with susceptibility to cloxacillin (94%) and amoxicillin and/or clavulanic acid (92%), respectively. Staphylococcus aureus and Escherichia coli were the most common bacteria with low rate of antimicrobial resistance. Amoxicillin and/or clavulanic acid and an adjunctive clindamycin are appropriate antimicrobial therapy for empiric treatment for NF in our setting. Amoxicillin and/or clavulanic acid and an adjunctive clindamycin can be used as an empiric treatment for NF.

Serotype diversity and antimicrobial susceptibility profiles of Actinobacillus pleuropneumoniae isolated in Italian pig farms from 2015 to 2022

Actinobacillus pleuropneumoniae (APP) is a bacterium frequently associated with porcine pleuropneumonia. The acute form of the disease is highly contagious and often fatal, resulting in significant economic losses for pig farmers. Serotype diversity and antimicrobial resistance (AMR) of APP strains circulating in north Italian farms from 2015 to 2022 were evaluated retrospectively to investigate APP epidemiology in the area. A total of 572 strains isolated from outbreaks occurring in 337 different swine farms were analysed. The majority of isolates belonged to serotypes 9/11 (39.2%) and 2 (28.1%) and serotype diversity increased during the study period, up to nine different serotypes isolated in 2022. The most common resistances were against tetracycline (53% of isolates) and ampicillin (33%), followed by enrofloxacin, florfenicol and trimethoprim/sulfamethoxazole (23% each). Multidrug resistance (MDR) was common, with a third of isolates showing resistance to more than three antimicrobial classes. Resistance to the different classes and MDR varied significantly depending on the serotype. In particular, the widespread serotype 9/11 was strongly associated with florfenicol and enrofloxacin resistance and showed the highest proportion of MDR isolates. Serotype 5, although less common, showed instead a concerning proportion of trimethoprim/sulfamethoxazole resistance. Our results highlight how the typing of circulating serotypes and the analysis of their antimicrobial susceptibility profile are crucial to effectively manage APP infection and improve antimicrobial stewardship.

Resistome Analysis of Klebsiella pneumoniae Complex from Residential Aged Care Facilities Demonstrates Intra-facility Clonal Spread of Multidrug-Resistant Isolates.

Antimicrobial-resistant Klebsiella pneumoniae is one of the predominant pathogens in healthcare settings. However, the prevalence and resistome of this organism within residential aged care facilities (RACFs), which are potential hotspots for antimicrobial resistance, remain unexplored. Here, we provide a phenotypic and molecular characterization of antimicrobial-resistant K. pneumoniae isolated from RACFs. K. pneumoniae was isolated from urine, faecal and wastewater samples and facility swabs. The antimicrobial susceptibility profiles of all the isolates were determined and the genomic basis for resistance was explored with whole-genome sequencing on a subset of isolates. A total of 147 K. pneumoniae were isolated, displaying resistance against multiple antimicrobials. Genotypic analysis revealed the presence of beta-lactamases and the ciprofloxacin-resistance determinant QnrB4 but failed to confirm the basis for the observed cephalosporin resistance. Clonal spread of the multidrug-resistant, widely disseminated sequence types 323 and 661 was observed. This study was the first to examine the resistome of K. pneumoniae isolates from RACFs and demonstrated a complexity between genotypic and phenotypic antimicrobial resistance. The intra-facility dissemination and persistence of multidrug-resistant clones is concerning, given that residents are particularly vulnerable to antimicrobial resistant infections, and it highlights the need for continued surveillance and interventions to reduce the risk of outbreaks.

Frequency and antimicrobial susceptibility profile of Methicillin-resistant Staphylococcus aureus isolated from Pus and Swab samples in a Teaching Hospital of Lahore

Background: Staphylococcus is a ubiquitous bacterium and well-known pathogen causing a variety of infections. The global spread of MRSA constitutes one of the most prevailing challenges to the management of infections caused by this bug.&#x0D; Aim: To determine the frequency of MRSA and antibiogram profile of S. aureus recovered from various clinical samples.&#x0D; Setting: Microbiology Laboratory of Shalamar Hospital Lahore.&#x0D; Methods: The data of the Staphylococcus isolates including MRSA from various pus and swab samples was collected through Electronic Medical Record of the Shalamar Hospital from 1st Jan to 31st Dec 2021. S. aureus was identified by standard protocol including Gram stain, catalase, coagulase, and DNase tests. Antimicrobial susceptibility was carried out by modified Kirby Bauer method. MRSA frequency was determined by the result of sensitivity to cefoxitin.&#x0D; Results: Out of 885 samples submitted for culture, 517 (58.4%) were reported for microbial growth of a known pathogen. The most frequently isolated pathogen was S. aureus (37.9%), followed by E. coli (22.4%), other members of Enterobacteriaceae family (17.8%), Pseudomonas (15.5%), Enterococcus (3.5%), Candida (2.1%), and Streptococcus (0.8%). Amongst S. aureus, MRSA was documented in 46.9% cases. Substantial difference was detected in the susceptibility pattern of methicillin-sensitive and resistant staphylococci. All staphylococci were resistant to ampicillin while no vancomycin resistance was encountered.&#x0D; Conclusion: MRSA was seen in the local population with a high frequency of 46.9% and such MRSA also showed marked resistance against other commonly used antibiotics. Fortunately no vancomycin-resistant S. aureus was reported.

Molecular epidemiology of carbapenem-resistant gram-negative bacilli in Ecuador

IntroductionCarbapenem-resistant gram-negative bacilli are a worldwide concern because of high morbidity and mortality rates. Additionally, the increasing prevalence of these bacteria is dangerous. To investigate the extent of antimicrobial resistance and prioritize the utility of novel drugs, we evaluated the molecular characteristics and antimicrobial susceptibility profiles of carbapenem-resistant Enterobacterales, Pseudomonas aeruginosa and Acinetobacter baumannii in Ecuador in 2022.MethodsNinety-five clinical isolates of carbapenem non-susceptible gram-negative bacilli were collected from six hospitals in Ecuador. Carbapenem resistance was confirmed with meropenem disk diffusion assays following Clinical Laboratory Standard Institute guidelines. Carbapenemase production was tested using a modified carbapenemase inactivation method. Antimicrobial susceptibility was tested with a disk diffusion assay, the Vitek 2 System, and gradient diffusion strips. Broth microdilution assays were used to assess colistin susceptibility. All the isolates were screened for the blaKPC,blaNDM,blaOXA-48,blaVIM and blaIMP genes. In addition, A. baumannii isolates were screened for the blaOXA-23, blaOXA-58 and blaOXA-24/40 genes.ResultsCarbapenemase production was observed in 96.84% of the isolates. The blaKPC, blaNDM and blaOXA-48 genes were detected in Enterobacterales, with blaKPC being predominant. The blaVIM gene was detected in P. aeruginosa, and blaOXA-24/40 predominated in A. baumannii. Most of the isolates showed co-resistance to aminoglycosides, fluoroquinolones, and trimethoprim/sulfamethoxazole. Both ceftazidime/avibactam and meropenem/vaborbactam were active against carbapenem-resistant gram-negative bacilli that produce serin-carbapenemases.ConclusionThe epidemiology of carbapenem resistance in Ecuador is dominated by carbapenemase-producing K. pneumoniae harbouring blaKPC. Extensively drug resistant (XDR) P. aeruginosa and A. baumannii were identified, and their identification revealed the urgent need to implement strategies to reduce the dissemination of these strains.