High frequency of carbapenemase in extensively drug-resistant Acinetobacter baumannii isolates in central Iran.

OBJECTIVES: We assessed the frequency of occurrence for infections caused by wild-type A. baumannii, multidrug-resistant (MDR) or XDR A. baumannii, and CRAB. We detected different antibiotic resistance genes in the genomes of infectious A. baumannii strains from central Iran. METHODS: This study investigated 546 clinical patient samples for the presence of A. baumannii by using conventional culture methods and PCR. Antibiotic resistance profiles, and the phenotypic and genotypic characteristics of various antibiotic genes were analyzed. RESULTS: Out of 546 samples, 87 (15.9%) A. baumannii isolates were obtained using culture and all culture positive samples were also positive by PCR. The most effective antibiotics were polymyxin B (n = 84 strains) (96.6% susceptibility), colistin (n = 81) (93.1%), and ampicillin/sulbactam (n = 18) (20.7%). All clinical A. baumannii isolates were ESBL-positive. The number of CRAB was 84 (96.5%). All CRAB isolates were both MDR and XDR. Of all CRAB isolates, 78 out of 84 (92.4%) produced metallo-ß-lactamase (MBL) by phenotypic diagnosis. The most abundant genes were blaPER (32/87; 36.7%), blaTEM (29/87; 33.3%), blaVEB (26/87; 29.8%) for ESBL and Ambler class D ß -lactamases included blaOXA-23 (69/84; 82.1%), blaOXA-24 (46/84; 54.7%), MBLs included blaVIM (51/84; 60.7%), and blaIMP (28/84; 33.3%) for carbapenemase. CONCLUSION: High frequencies of XDR A. baumannii and CRAB (96.5%) were detected in central Iran. Quick and accurate diagnosis, appropriate isolation of patients colonized or infected by CRAB isolates, application of accurate and effective infection control policies and programs, and appropriate preventive measures are deemed helpful in preventing the further spread of these resistant and clinically highly relevant strains.

High frequency of NDM-1 and OXA-48 carbapenemase genes among Klebsiella pneumoniae isolates in central Iran.

BACKGROUND: The emergence and distribution of multidrug-resistant (MDR) and carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a global health threat. Therefore, this study aimed to investigate the frequency and antibiotic resistance patterns of MDR, extensively drug-resistant (XDR), and CRKP, as well as the antibiotic resistance genes of Klebsiella pneumoniae (K. pneumoniae) isolates from patients' infectious samples from central Iran. METHODS: This study examined 546 clinical samples of patients to identify K. pneumoniae. The isolates were investigated for their antibiotic resistance profile, extended-spectrum ß-lactamase (ESBL), AMPC ß-lactamase, carbapenemase resistance, sulfonamide, tetracycline, plasmid-mediated quinolone resistance (PMQR) along with their resistance genes, integrase, and quaternary ammonium compounds (qac) by polymerase chain reaction (PCR). RESULTS: Out of 546 clinical samples, 121 (22.1%) cases of K. pneumoniae were identified using culture and PCR methods. The highest antibiotic resistance rates were found for ampicillin (119/121; 98.3%), cotrimoxazole (78/121; 64.4%), and cefixime, cefotaxime, ceftriaxone, and ceftazidime as a group (77/121; 63.6%). Tigecycline, colistin, and fosfomycin were the most effective antimicrobial agents with 98.4%, 96.7%, and 95.9% susceptibility, respectively. The amount of CRKP was 51 (42.1%). All CRKP isolates were MDR. The most abundant genes were blaTEM (77/77; 100%), blaCTX-M1 (76/77; 98.7%), blaSHV (76/77; 98.7%), blaCTX-M15 (73/77; 94.8%) for ESBL; blaCIT 28 (48.3%) and blaCMY-2 26 (44.8%) for AMPC ß-lactamase; and blaOXA-48 46 (90.1%) and blaNDM 36 (70.5%) for carbapenemase. Among the PMQR determinants, qnrB (25/52; 48%), qnrS (19/52; 36.5%), and qnrA (11/52; 21.1%) were positive from the isolates. TetA and tetB were recognized in 25 (44.6%) and 17 (30.3%) isolates, respectively. Class 1 and 2 integrons were recognized in 97 (80.1%) and 53 (43.8%) isolates, respectively. CONCLUSIONS: Due to the high prevalence of MDR and CRKP in central Iran, tracking and immediate intervention are necessary for control and inhibition of K. pneumoniae resistant isolates. Tigecycline, colistin, and fosfomycin are the best treatment options for treatment of patients with CRKP in this geographical area.

The significant role of Carbapenems-resistant Acinetobacter Baumannii in mortality rate of patients with COVID-19.

Background: Infections caused by Acinetobacter baumannii, especially carbapenem-resistant (CR) strains, pose important challenges in patients with COVID-19 infection. Therefore, in the present study, we investigated co-infection and antimicrobial resistance patterns, as well as the role of A. baumannii in the outcome of patients with COVID-19. Materials and methods: Between February 2019 and January 2021, 141 patients with A. baumannii infections were detected from seven different hospitals (A to G) in Arak, Iran, and the antibacterial susceptibility pattern of these isolates was evaluated using disk diffusion and E-test methods. Forty-seven of these patients were co-infected with COVID-19. During the study, the data about the clinical course, demographic data, and the role of A. baumannii infections in the mortality rate of COVID-19 patients were collected. Results: Hospitals A and B reported the most patients, with 53 (38%) and 47 (33%), respectively. Additionally, most cases (105 cases, 75%) were reported from surgical and general ICUs. Mechanical ventilators were detected as predisposing factors in 95 (67%) patients, and infection was detected in 20% of patients on the 10th day after intubation. All of the A. baumannii isolates were resistant to different classes of antibiotics, such as carbapenems. Notably, 33% (47 patients) were also positive for COVID-19, and 68% (32 patients) died due to the infection. Statistical analysis showed a significant role of A. baumannii co-infection in the mortality rate of COVID-19 patients (p-value 0.05). Conclusion: co-infection with A. baumannii is one of the most important challenges in COVID-19 patients. Our results showed that all isolated bacteria were CR and significantly increased mortality rates in COVID-19 patients.

Antecedentes: Las infecciones causadas por Acinetobacter baumannii, especialmente las cepas resistentes a carbapenem (CR), plantean desafíos importantes en pacientes con infección por COVID-19. Por lo tanto, en el presente estudio investigamos los patrones de coinfección y resistencia a los antimicrobianos, así como el papel de A. baumannii en el desenlace de los pacientes con COVID-19.Materiales y métodos: entre febrero de 2019 y enero de 2021, se detectaron 141 pacientes con infecciones por A. baumannii de siete hospitales diferentes (A a G) en Arak, Irán, y se evaluó el patrón de susceptibilidad antibacteriana de estos aislamientos mediante difusión en disco y E- métodos de prueba. Cuarenta y siete de estos pacientes estaban coinfectados con COVID-19. Durante el estudio, se recopilaron datos sobre datos demográficos, curso clínico y el papel de las infecciones por A. baumannii en la tasa de mortalidad de los pacientes con COVID-19.Resultados: Los hospitales A y B reportaron mayor número de pacientes con 53 (38%) y 47 (44%), respectivamente. Además, la mayoría de los casos (105 casos, 75%) se informaron desde la UCI quirúrgica y general. Los ventiladores mecánicos se detectaron como factores predisponentes en 95 (67%) pacientes y la infección se detectó en el 20% de los pacientes al décimo día después de la intubación. Todos los aislamientos de A. baumannii fueron resistentes a diferentes clases de antibióticos, como los carbapenémicos. El 33,6% (47 pacientes) también dieron positivo a COVID-19, y el 68% (32 pacientes) fallecieron a causa de la infección. El análisis estadístico mostró un papel significativo de la coinfección por A. baumannii en la tasa de mortalidad de los pacientes con COVID-19 (valor de p 0,05).Conclusión: la coinfección con A. baumannii es uno de los desafíos más importantes en pacientes positivos para COVID-19. Nuestros resultados mostraron que todas las bacterias aisladas eran CR y aumentaron significativamente las tasas de mortalidad en pacientes con COVID-19.

Common Etiological Agents in Adult Patients with Gastroenteritis from Central Iran.

Aims: This study represents the first analysis from Iran for both the frequency of the most common causes of infectious diarrhoea and their antibiotic resistance patterns in adult patients. Methods: Adult stool specimens (n = 211) were analyzed. Stool specimens were analyzed using standard microbiological, polymerase chain reaction, and reverse transcription polymerase chain reaction tests to identify bacterial, parasitic, and viral enteropathogens. Antibiotic resistance profiles were determined. Results: Enteropathogens were identified in 46.4% (98/211) of the surveyed samples. This included 33.1% (70/211) bacterial infections, including 9.9% (21/211) diarrheagenic Escherichia coli (DEC) and 8.5% (18/211) Shigella spp. We detected 7.1% (15/211) parasitic infections (mostly Giardia lamblia) and 6.1% (13/211) viral infections (mostly adenovirus). The DEC and Shigella spp. isolates included many multi-drug resistant (MDR) isolates (95.2% and 77.7%, respectively), and extended spectrum-ß-lactamase (ESBL) genes were often present (57.1% and 61.1%, respectively). The most commonly identified ESBL genes in the DEC and Shigella spp. isolates were blaTEM (100% in both species), blaCTX-M15 (91.6% and 100%, respectively), AmpC blaCIT (80% and 100%, respectively), and blaDHA (80% and 100%, respectively). Conclusions: Bacterial infection was the primary cause of infectious diarrhea, affecting one-third of the adults. The frequency of DEC and Shigella spp. was higher than for other enteropathogens. The high prevalence of MDR, the elevated incidence of ESBL genes among Shigella spp. and DEC isolates, and the presence of quinolone resistance in the Salmonella spp. isolates represent a significant challenge for gastroenteritis diagnosis and treatment in this region.

Quinolone resistant Salmonella species isolated from pediatric patients with diarrhea in central Iran.

BACKGROUND: This study aimed to investigate the frequency and the antibiotic resistance patterns of Salmonella species that were isolated from infectious diarrhea samples taken from pediatric patients in central Iran. METHODS: The study analyzed 230 stool specimens that were cultured on XLD, MacConkey agar and GN broth. Polymerase chain reaction (PCR) assay was used to identify the Salmonella genus. The antibiotic resistance profiles and the frequency of quinolone and integron genes were obtained. RESULTS: Out of 230 samples of infectious diarrhea, 21 (9.1%) cases of Salmonella spp. were identified using culture methods. Another 28 (12.1%) samples had positive PCR results, with S. serovar Paratyphi B and C (9/21; 42.8%) and S. Typhi (3/21; 14.3%) being the most recognized. The highest antibiotic resistance rates were found for nalidixic acid (15/21; 71.4%), tetracycline (9/21; 42.8%). However, six (28.5%) of isolates were found resistant to cotrimoxazole, ampicillin and chloramphenicol. Among the plasmid-mediated quinolone resistance (PMQR) determinants, qnrS, qnrA, and qnrB were positive in (9/15; 60%), (6/15; 40%) and (3/15; 20%) of the isolates, respectively. Class 1 and 2 integrons were identified in 15 (71.4%) and 3 (14.3%) isolates, respectively. CONCLUSION: High rates of quinolone resistant and low frequency of MDR Salmonella spp. isolates were identified in central Iran, similar to findings in other parts of Asia. To prevent the spread of these resistant strains, the antimicrobial resistance of Salmonella spp. isolates should be under constant surveillance, and empiric antibiotic therapy should be adapted appropriately.

Multi-Drug-Resistant Diarrheagenic Escherichia coli Pathotypes in Pediatric Patients with Gastroenteritis from Central Iran.

BACKGROUND: Diarrheagenic Escherichia coli (DEC) is a significant cause of gastroenteritis and a major public health problem. This study investigates the prevalence and the antibiotic resistance patterns of DEC that were isolated from infectious diarrhea samples of pediatric patients from central Iran. PATIENTS AND METHODS: Pediatric diarrhea samples were collected from 230 pediatric patients visiting the hospital. E. coli pathotypes were diagnosed by using conventional culture methods and PCR. Antibiotic resistance profiles, the frequency of multi-drug resistance (MDR), and the phenotypic and genotypic characteristics of extended spectrum-ß-lactamase (ESBL), AmpC and integron-associated genes were analyzed. RESULTS: Of the 230 samples of infectious diarrhea, 91 (39.5%) produced E. coli isolates. Of these, 32 cases (35.1%) were identified as DEC by culture and PCR. The frequency of the E. coli pathotypes obtained was as follows: EAEC 11/32 (34.3%), EPEC 9/32 (28.1%), ETEC 6/32 (18.7%), EIEC 3/32 (9.3%), and EHEC 3/32 (9.3%). The antibiotic resistance rates were greater for nalidixic acid (30/32; 93.7%), ampicillin (29/32; 90.6%), and tetracycline (25/32; 78.1%) than for any of the other tested antibiotics. High levels of MDR (25/32; 78.1%) and the presence of ESBL (18/32; 56.2%) and AmpC (9/32; 28.1%) were observed in the DEC isolates. The isolates showed a higher frequency of the ESBL genes [blaTEM (18/18; 100%), blaCTX-M15 (17/18; 94.4%)], and AmpC [bla CIT (4/9; 44.4%) and blaDHA (4/9; 44.4%)] than of the other ESBL and AmpC genes. CONCLUSION: Compared to the previous study, DEC appeared to be the second-most abundant agent of diarrhea in pediatric patients after Campylobacter jejuni, with frequent MDR and ESBL presence.

The effects of chromium and vitamin D3 co-supplementation on insulin resistance and tumor necrosis factor-alpha in type 2 diabetes: a randomized placebo-controlled trial.

The current study was conducted to assess the effects of simultaneous usage with vitamin D3 and chromium picolinate (CrPic) supplementations on homeostasis model assessment of insulin resistance (HOMA-IR), fasting blood glucose (FBS), hemoglobin A1c (HbA1c), tumor necrosis factor-α (TNF-α), and lipid profile in type 2 diabetes mellitus (T2DM). Ninety-two patients with T2DM were randomly allocated to the following 4 groups for 4 months: (I) placebo of vitamin D3 (n = 23); (II) vitamin D3 supplement at a dose of 50 000 IU/week (n = 23); (III) CrPic supplement at a dose of 500 µg/day (n = 23); and (IV) both vitamin D3 at a dose of 50 000 IU/week and CrPic at a dose of 500 µg/day (n = 23). HOMA-IR levels increased significantly in groups I and II after the intervention. However, this increase in group I was significantly higher than that in group II after the treatment. HOMA-IR levels were controlled in groups III and IV during the intervention. TNF-α decreased significantly in groups II, III, and IV after the intervention. FBS, HbA1c, and lipid profile did not change significantly in total groups after the intervention. It seems that chromium and vitamin D3 co-supplementation are probably effective in controlling HOMA-IR by decreasing TNF-α in T2DM. Novelty Chromium alone and/or in simultaneous pretreatment with vitamin D3 is more effective than vitamin D3 in controlling HOMA-IR in T2DM. Chromium and vitamin D3 alone and/or in simultaneous pretreatment decrease TNF-α in T2DM.

Frequency of Listeria monocytogenes Isolated from Diarrhea Samples of Pediatric Patients at Central Iran.

BACKGROUND: Listeria monocytogenes is a primarily foodborne bacterial pathogen that is one of the causative agents of gastroenteritis. However, the prevalence of L. monocytogenes infection in pediatric patients with diarrheal disease is not clearly identified in the Iranian population. This study aimed to investigate the frequency of L. monocytogenes isolates found in infectious diarrhea samples of pediatric patients in an Iranian population. METHODS: A total of 173 infectious diarrhea samples collected from pediatric patients were used in this crosssectional study. Samples were collected from patients referred to the Children's Educational-Therapeutic Center affiliated with the Arak University of Medical Sciences in Arak, Iran from May-September 2015. To identify the presence of L. monocytogenes, the samples were directly inoculated into the Listeria Enrichment Broth Base through cold enrichment, then plated onto isolated exclusive Listeria Selective Agar Base. As an alternative method for identifying L, monocytogenes, Polymerase Chain Reaction (PCR) of the InlA gene was used. RESULTS: Of the 173 infectious diarrhea samples, eight (4.6%) with L. monocytogenes were identified using exclusive culture media, while nine (5.2%) were identified using PCR. The majority of L. monocytogenes infections (seven cases (77.7%)) were observed in children under the age of five. CONCLUSION: Our results show L. monocytogenes infections to have a low prevalence for causing diarrhea in children in the central region of Iran. This should be taken into consideration by pediatricians when treating intestinal diseases.

Multidrug-resistant Shigella infection in pediatric patients with diarrhea from central Iran.

Background: Shigella spp. are primary pathogens of diarrhea in children worldwide. Emergence of resistance to fluoroquinolones and third-generation cephalosporins is crucial in the management of pediatric shigellosis. We determined the prevalence and the antibiotic resistance patterns of Shigella species isolated from pediatric patients in central Iran. Materials and methods: Pediatric diarrhea samples (n=230) were cultured on MacConkey and XLD agar media and in GN broth. Genus-specific PCR for ipaH was also used for detection directly from fecal specimens. Antibiotic resistance and the frequency of ESBL and AmpC genes were determined. Results: Out of the 230 samples, 19 (8.2%) cases of Shigella spp. were identified using culture. Twenty-six samples were positive by PCR (11.3%), S. flexneri (4/19; 21%) and S. sonnei (15/19; 78.9%) being the most detected. The highest antibiotic resistance rates were found for cotrimoxazole (19/19; 100%), ampicillin (16/19; 84.2%), cefixime (13/19; 68.4%) and ceftriaxone (12/19; 63.1%). Ten cases showed phenotypic ESBL presence and all these strains were positive for bla TEM, bla CTX-M-1, and bla CTX-M-15. Three strains were AmpC positive, all of which harbored bla CMY-2 and two contained bla CIT. Of the 19 Shigella isolates 5 (26.3%), 2 (10.5%), and 1 (5.2%) were phenotypically resistant to nalidixic acid, ciprofloxacin, and norfloxacin, respectively. Class 1 integron was found in 18 (94.7%) isolates whereas class 2 integron was found in 19 (100%) strains. Conclusion: We found a considerable presence of Shigella species with elevated antibiotic resistance levels. In particular, the resistance to third-generation cephalosporins (ESBL) and ciprofloxacin must be taken seriously.

Quinolone and Macrolide-Resistant Campylobacter jejuni in Pediatric Gastroenteritis Patients from Central Iran.

Aims: To determine the prevalence and the antibiotic resistance patterns of Campylobacter jejuni isolated from pediatric diarrhea patients in central Iran. Materials and Methods: Stool specimens (n = 230) were investigated using a modified Gram stain, two specific culture media, and C. jejuni-specific PCR. Antibiotic resistance profiles and relevant resistance genes were determined. Genetic relationships among a selection of the isolates were studied by Fla typing. Results: Out of the 230 diarrhea samples, 48 (20.8%) cases of C. jejuni were identified using modified Gram stain, 45 (19.5%) using the culture media, and 76 (33%) cases were identified using PCR. The highest antibiotic resistance rates were observed in 37 (82.2%) strains against tetracycline, in 32 (71.1%) against ciprofloxacin, and in 31 (68.8%) against erythromycin. Twenty (44.4%) isolates were resistant to ciprofloxacin and erythromycin simultaneously. Genotypic investigations found 36 (97.3%) strains carrying the tet (o) gene, 31 (96.8%) harboring the cmeB gene, 22 (68.7%) strains with the gyrA6 gene, 20 (64.5%) strains containing a 23S rRNA mutation, and 21 (65.6%) strains with the qnrS gene. Fla typing of a random subset of 14 strains revealed 11 different types showing the genomic diversity of the isolates. Strains sharing the same Fla type could be easily distinguished by their resistance gene profile. Conclusions: This is the first study to demonstrate that genetically diverse quinolone-macrolide-resistant C. jejuni is an important cause of gastroenteritis in children from central Iran. Pediatricians should consider these resistance features once the antibiotic prescription is necessary for prevention of possible complications, especially in those under 5 years of age. Of note, most cases of Campylobacter diarrhea are self-limiting and antibiotics should only be prescribed in those cases where severe complications evolve.

Low Prevalence of Aeromonas hydrophilain Infectious Diarrhea Samples of Pediatric Patients in Arak, Iran.

BACKGROUND: Aeromonashydrophila (A. hydrophila) is an aquatic bacterium that can cause a spectrum of infectious diseases, including both gastrointestinal and extraintestinal infections. Due to the high rate of diarrheal infections in pediatric patients in central Iran, this study was designed to determine the frequency of A. hydrophila in diarrhea samples from children in this region. METHODS: In this descriptive cross-sectional study, diarrheal stool specimens were collected from 200 children admitted between February and October of 2015 to educational and medical centers affiliated with the Arak University of Medical Sciences. The samples were analyzed both phenotypically by culture and genotypically by the polymerase chain reaction (PCR). RESULTS: A. hydrophila was isolated from two of the 200 samples tested (1%). The presence of bacterial genetic markers further confirmed the diagnosis. CONCLUSION: Based on this study, A. hydrophilais not highly prevalent in children with diarrhea in Arak; however clinical diagnostic laboratory personnel should be aware of the possible presence of A.hydrophila in children with diarrhea as it can cause dangerous health problems in both them and young adolescents.