Antimicrobial Drug Susceptibility Testing Research Articles

Artificial intelligence applications in the diagnosis and treatment of bacterial infections.

The diagnosis and treatment of bacterial infections in the medical and public health field in the 21st century remain significantly challenging. Artificial Intelligence (AI) has emerged as a powerful new tool in diagnosing and treating bacterial infections. AI is rapidly revolutionizing epidemiological studies of infectious diseases, providing effective early warning, prevention, and control of outbreaks. Machine learning models provide a highly flexible way to simulate and predict the complex mechanisms of pathogen-host interactions, which is crucial for a comprehensive understanding of the nature of diseases. Machine learning-based pathogen identification technology and antimicrobial drug susceptibility testing break through the limitations of traditional methods, significantly shorten the time from sample collection to the determination of result, and greatly improve the speed and accuracy of laboratory testing. In addition, AI technology application in treating bacterial infections, particularly in the research and development of drugs and vaccines, and the application of innovative therapies such as bacteriophage, provides new strategies for improving therapy and curbing bacterial resistance. Although AI has a broad application prospect in diagnosing and treating bacterial infections, significant challenges remain in data quality and quantity, model interpretability, clinical integration, and patient privacy protection. To overcome these challenges and, realize widespread application in clinical practice, interdisciplinary cooperation, technology innovation, and policy support are essential components of the joint efforts required. In summary, with continuous advancements and in-depth application of AI technology, AI will enable doctors to more effectivelyaddress the challenge of bacterial infection, promoting the development of medical practice toward precision, efficiency, and personalization; optimizing the best nursing and treatment plans for patients; and providing strong support for public health safety.

Nanopore sequencing of infectious fluid is a promising supplement for gold-standard culture in real-world clinical scenario.

Infectious diseases are major causes of morbidity and mortality worldwide, necessitating the rapid identification and accurate diagnosis of pathogens. While unbiased metagenomic next-generation sequencing (mNGS) has been extensively utilized in clinical pathogen identification and scientific microbiome detection, there is limited research about the application of nanopore platform-based mNGS in the diagnostic performance of various infectious fluid samples. In this study, we collected 297 suspected infectious fluids from 10 clinical centers and detected them with conventional microbiology culture and nanopore platform-based mNGS. The objective was to assess detective and diagnostic performance of nanopore-sequencing technology (NST) in real-world scenarios. Combined with gold-standard culture and clinical adjudication, nanopore sequencing demonstrated nearly 100% positive predictive agreements in microbial-colonized sites, such as the respiratory and urinary tracts. For samples collected from initially sterile body sites, the detected microorganisms were highly suspected pathogens, and the negative predictive agreements were relatively higher than those in the microbial-colonized sites, particularly with 100% in abscess and 95.7% in cerebrospinal fluid. Furthermore, consistent performance was also observed in the identification of antimicrobial resistance genes and drug susceptibility testing of pathogenic strains of Escherichia coli, Staphylococcus aureus, and Acinetobacter baumannii. Rapid NST is a promising clinical tool to supplement gold-standard culture, and it has the potential improve patient prognosis and facilitate clinical treatment of infectious diseases.

Isolation, Identification and Drug Resistance Rates of Bacteria from Pigs in Zhejiang and Surrounding Areas during 2019-2021.

This study aimed to determine the prevalence of bacterial diseases in pig farms in various regions of Zhejiang Province and surrounding areas. A total of 526 samples were collected from 85 pig farms in Zhejiang Province and surrounding areas. In this study, samples were analyzed using bacterial isolation and purification, Gram staining, PCR amplification, and antimicrobial susceptibility testing. A total of 36 Pasteurella multocida (Pm) isolates were detected, with an isolation rate of 6.84%; 37 Bordetella bronchiseptica (Bb) isolates were detected, with an isolation rate of 7.03%; 60 Glasserella parasuis (G. parasuis) isolates were detected, with an isolation rate of 11.41%; 170 Escherichia coli (E. coli) isolates were detected, with an isolation rate of 32.32%; 67 Streptococcus suis (SS) isolates were detected, with an isolation rate of 12.74%; 44 Actinobacillus pleuropneumoniae (APP) isolates were detected, with an isolation rate of 8.37%; and 7 Salmonella enteritis (SE) isolates were detected, with an isolation rate of 1.33%. Antimicrobial drug susceptibility testing against 21 types of antibiotics was carried out on the isolated strains, and the results showed that 228 strains had varying degrees of resistance to 21 antibiotics, including Pm, Bb, E. coli, and APP, with the highest resistance to lincomycin, at 100%. Pm and APP were the most sensitive to cephalothin, with resistance rates of 0. In terms of strains, Pm had the highest overall sensitivity to 21 antibiotics, and E. coli had the highest resistance. In short, bacterial diseases in Zhejiang and the surrounding areas were harmful, and the drug resistance situation was severe. This study provides scientific guidance for the clinical treatment of bacterial diseases.

Co-occurrence of blaNDM-1, rmtC, and mcr-9 in multidrug-resistant Enterobacter kobei strain isolated from an infant with urinary tract infection

The co-emergence of mcr and carbapenem resistance genes in Gram-negative bacteria is a serious problem. This study aims to clarify the genetic characteristic of one novel multidrug-resistant Enterobacter kobei EC1382 with mcr-9 causing urinary tract inflammation in an infant. Antimicrobial drug susceptibility testing was performed for this isolate using the broth microdilution method. Whole-genome sequencing was performed using the Illumina PacBio RS II platform and HiSeq platform, and the antimicrobial resistance genes, mobile elements, and plasmid replicon types were identified. Conjugation analysis was performed using Escherichia coli C600 as recipients. Enterobacter kobei EC1382 was resistant to carbapenem, aminoglycoside, and cephalosporin. Twenty-five antimicrobial resistance genes were identified, including genes conferring resistance to carbapenem (blaNDM-1), colistin (mcr-9), and aminoglycosides (rmtC). The blaNDM-1 gene, accompanied by bleMBL and rmtC located downstream of an ISCR14 element, was detected in the IncFII(Yp) type plasmid pEC1382-2. Interestingly, although E. kobei EC1382 was susceptible to colistin, it had three identical mcr-9 genes (two in the chromosome and one in the IncHI2-type plasmid pEC1382-1). The backbone (∼12.2-kb genetic fragment) of these mcr-9 (flanked by IS903B and IS481-IS26) regions were conserved in this strain, and they were found to be present in various bacteria as three types, implying a silent distribution. To the best of our knowledge, this is the first study to demonstrate the coexistence of blaNDM-1, rmtC, and mcr-9 in E. kobei. The silent prevalence of mcr-9 in bacteria may be a threat to public health.

Bacterial Profile and Antibiogram of Pathogens Causing Surgical Site Infections at Mnazi Mmoja Hospital in Zanzibar, Tanzania

A hospital based cross sectional study was done to determine bacterial profile and antibiogram of pathogens causing surgical site infections at Mnazi Mmoja Hospital in Zanzibar, Tanzania. The study was conducted from May to July 2017. We enrolled a total of 121 patients who underwent different surgical procedures and met study inclusion criteria. Pus swabs were collected and cultured as per standard operating procedures. Bacterial identification was then performed using biochemical tests and Analytical Profile Index test for Enterobacteriaceae (API 20E). Antimicrobial drug susceptibility testing was performed using Kirby Bauer disc diffusion technique. Data were analyzed using Statistical Package for Social Sciences (SPSS) version 21.0. Of 121 patients that were enrolled in the study, 75 (62%) developed surgical site infection (SSI). A total of 106 isolates were recovered from patients with positive culture results. The majority of the isolates, 92/106 (87%) were Gram-negative bacteria. The most predominant bacterium was Pseudomonas aeruginosa, 29/106 (27%) in all surgical Departments. Some of the isolated pathogens were multi-drug resistant (29/106; 27%), including Extended Spectrum Beta Lactamase (ESBL) producers (24/92; 26%), Methicillin Resistant Stahylococcus aureus (MRSA) (3/9; 33%) and Induced Clindamycin Resistance (ICR) strains (2/14; 14%). K. pneumoniae isolates showed the highest resistance towards most tested antibiotics (24.1-100%), and 24% of P. aeruginosa isolates were resistant to meropenem. In conclusion, P. aeruginosa was the most common isolated pathogen from patients with SSI in Zanzibar and the majority of the pathogens showed high resistance to commonly prescribed antimicrobial agents used in the hospital settings.

Association of bacterial isolates and antimicrobial susceptibility between prostatic fluid and urine samples in canine prostatitis with concurrent cystitis

Most old, intact male dogs usually have prostate disorders, especially benign prostatic hypertrophy and prostatitis with or without abscesses, and concurrent cystitis. The successful treatment of dogs with prostatitis concurrent with cystitis has relied on choosing an appropriate antimicrobial drug based on a bacterial culture and drug sensitivity testing. The objective of the study was to compare the prevalence of bacterial species and results of drug susceptibility testing of bacteria that were isolated from the prostatic fluids and urine samples that were collected from dogs with both prostatitis and cystitis. One hundred and sixty intact male dogs, who presented with both diseases, were recruited for the study. The disease diagnoses were based on clinical history notes, physical examinations, abdominal ultrasonography, prostatic fluid cytology, urinalysis and bacterial cultures from both prostatic fluid and urine samples. The bacterial culture results demonstrated that the major species that were detected in either the prostatic fluid or urine samples were Staphylococcus spp., Escherichia coli, Pseudomonas spp., Streptococcus spp., Proteus mirabilis and Klebsiella pneumoniae. Staphylococcus spp. (26.5 %, 43/162) and Escherichia coli (26.1 %, 12/46) were the most prevalent species from the prostatic fluid and urine samples, respectively. Statistical tests revealed that there were no significantly different prevalence levels among the isolated bacteria between the prostatic fluid and urine samples.Imipenem and gentamicin were the most potent antimicrobial drugs tested against the bacterial isolates in the present study. However, the administration of imipenem to treat prostatitis and cystitis in dogs was of concern. Interestingly, there were no significant differences in the antimicrobial drug susceptibility trends between the prostatic fluid and urine samples. Based on these results, a urine sample might be considered as an optional sample for bacterial cultures and antimicrobial drug susceptibility testing when it is not possible to collect a prostatic fluid sample.

Prevalence of asymptomatic urinary tract infection due to escherichia coli among pregnant women attending ANC clinic at BRIMS teaching hospital

Introduction: Urinary tract infection (UTI) due to Escherichia coli (E. coli) is a common health problem among women. Pregnant women are at increased risk from both symptomatic and asymptomatic UTI because of the physiologic changes associated with pregnancy which may cause complications such as pyelonephritis, chronic renal failure, premature delivery and foetal mortality. Our study aimed to check the prevalence of asymptomatic UTI due to E. coli and its antibiotic profile among pregnant women of Bidar district of North Karnataka, India. Materials and Methods: An independent study was done from January to February 2015 to investigate asymptomatic UTI among pregnant women attending Antenatal care clinic (ANC) of Bidar Institute of Medical sciences (BRIMS) Teaching hospital Bidar. 150 mid-stream urine samples were processed for culture and antimicrobial drug susceptibility testing at Department of Microbiology, BRIMS, Bidar as per the routine microbiological techniques. Diagnosis of UTI was made when there were at least 105 colony forming unit (CFU)/ml of urine. Isolates other than E. coli are not considered for this study. Results: Among 150 samples tested, 65 samples grown E. coli with colony count of 105 CFU/ml of urine. (43.33%).The Majority of pregnant women were in their 2nd and 3rd trimester and the mean age of study population was 23.46. The rate of UTI was highest among age group of 20-25 years. E. coli isolates showed highest resistance to antibiotics Ampicillin (96.92%), Cefuroxime (55.38%) and ceftriaxone (53.85%). It was uniformly sensitive to routinely used drugs for treatment of UTI. Discussion: Many Gram negative and Gram positive organisms including Yeast cause UTI in pregnant women. Our study revealed the high prevalence of asymptomatic UTI among pregnant women due to E. coli in Bidar (43.33%) as compared to studies conducted in other parts Karnataka. This study also showed the antibiotic profile of E. coli to different drugs tested and showed highe

Biofilm formation in uropathogenic Escherichia coli strains; Relationship with virulence factors and antimicrobial resistance

Background: Urinary tract infection (UTI) is a clinical condition with characteristic symptoms, colonization and multiplication of bacteria in significant numbers. At this juncture, antimicrobial resistance in uropathogens has become one of the major concerns globally. Therefore, the present study aimed to demonstrate the biofilm formation in uropathogenic Escherichia coli strains; characterize the phenotypic & genotypic virulence factors and their relationship with antimicrobial resistance. Methods and materials: In this study, 1000 suspected UTI cases were included. Urine samples were processed for culture and antimicrobial drug susceptibility testing. Only Escherichia coli isolates were further studied for production of biofilm, ESBL and haemolysin enzymes by phenotypic methods. Virulence genes, papEF, traT & PAI were detected by multiplex PCR. Molecular confirmation & characterization of virulence genes was done by Sanger sequencing. Results: From the 1000 urine samples, 395 E. coli were isolated. Higher resistance was observed with antibiotics - ampicillin (82.53%), cefuroxime (72.41%), amoxicillin-clavulanic acid (71.90%), ceftriaxone (66.58%), ciprofloxacin (65.82%) and cefepime (57.47%). In-vitro biofilm was formed by 71.39% isolates. Biofilm-forming strains developed higher resistance towards ampicillin, cefuroxime, amoxicillin-clavulanic acid, ciprofloxacin, cefepime and ceftriaxone. Phenotypic methods detected 62.3% isolates as ESBL producers and 40.2% were β-haemolytic. Virulence gene characterization revealed presence of traT in 73.2% strains, PAI & papEF among 62.9% and 33.5% strains. ESBL & Hemolysin producing UPEC exhibited higher resistant to ampicillin, amoxicillin-clavulanic acid, aztreonam, cefriaxone, cefuroxime, cefepime, ciprofloxacin, chloramphenicol & gentamicin. Statistically proved association was seen with gene RPAI and traT with antibiotics nitrofurantoin and amikacin. All the isolates were sensitive to nitrofurantoin, piperacillin-tazobactam, and imipenem. Strains showed 99% sequence identity and no mutations were detected. Conclusion: Increase in trend of resistance was observed with antibiotics which were routinely used to treat UTI. Results indicated significant correlation between phenotypic and genotypic virulence factors and antibiotic resistance. Antibiotics nitrofurantoin, piperacillin - tazobactam, and imipenem can be effective for severe UTIs. This study concludes that expression of virulence factors by UPEC strains is responsible for increased antibiotic resistance. Hence, characterizing the UPEC strains help clinicians to reach a better therapeutic outcomes and treatment regimens in this region.

Urinary Tract Infection in Pregnant Women at Kathmandu, Nepal

Background: Urinary tract infections “UTIs” are one of the frequently encountered problems during pregnancy. Untreated UTI can be associated with serious obstetric complications. Hence the management and prevention of UTI in pregnancy is the crucial factor for the sustained pregnant period. Hence the present study was designed to identify the pathogenic agents of UTI and its associated risk factors in antenatal mothers in two private hospitals at Kathmandu city.
 Aim: The main objective of the study was to identify the etiological agent and associated risk factor in Urinary tract infection among pregnant women attending the antenatal care service visit in a selected hospital.
 Study Design: Cross-sectional descriptive study.
 Place and Time of Study: The study was carried out under the supervision of University and field study was carried out in Kathmandu, Nepal from March 2019 to October 2019.
 Methods: The cross-sectional study was performed at the Norvic Hospital and Baidya and Banskota hospital from March 2019 to October 2019. In this cross-sectional study, a total of 510, clean catch midstream urine (MSU) samples were collected aseptically and analyzed using standard microbiology methods. Data for the factors associated with UTI were obtained by use of questionnaires and standard laboratory tests for selected underlying conditions concerning associated risk factors were collected using structured questionnaires and the sample was also processed for antimicrobial drug susceptibility testing.
 Results: The study revealed 193/510(37.84%) UTI prevalence among patients attending two hospitals in Kathmandu valley. Escherichia coli was the most prevalent bacterial uropathogen with 119/193(61.6%) followed by Klebsiella pneumoniae 35/193(18.13%), Staphylococcus aureus 22/193 (11.39%), Proteus mirabilis 7/193 (3.6%), Enterococcus faecalis 2/193 (1.0%), Enterobacter aerogenes2/193(1.0%) Serratia odorifera 3/193(1.5%), Streptococcus species3/193(1.5%).
 Conclusions: The high prevalence of urinary tract infection in pregnant women warrant the need to screen all pregnant women and treat those infected with appropriate antimicrobial regimens in order to reduce its complications. Urinary Tract Infection screening is essential in pregnant women.

Genomic characterization of antibiotic resistance-encoding genes in clinical isolates of Vibrio cholerae non-O1/non-O139 strains from Kolkata, India: generation of novel types of genomic islands containing plural antibiotic resistance genes.

Non-O1/non-O139 nontoxigenic Vibrio cholerae associated with cholera-like diarrhea has been reported in Kolkata, India. However, the property involved in the pathogenicity of these strains has remained unclear. The character of 25 non-O1/non-O139 nontoxigenic V. cholerae isolated during 8 years from 2007 to 2014 in Kolkata was examined. Determination of the serogroup showed that the serogroups O6, O10, O35, O36, O39, and O70 were represented by two strains in each serogroup, and the remaining isolates belonged to different serogroups. To clarify the character of antibiotic resistance of these isolates, an antibiotic resistance test and the gene analysis were performed. According to antimicrobial drug susceptibility testing, 13 strains were classified as drug resistant. Among them, 10 strains were quinolone resistant and 6 of the 13 strains were resistant to more than three antibiotics. To define the genetic background of the antibiotic character of these strains, whole-genome sequences of these strains were determined. From the analysis of these sequences, it becomes clear that all quinolone resistance isolates have mutations in quinolone resistance-determining regions. Further research on the genome sequence showed that four strains possess Class 1 integrons in their genomes, and that three of the four integrons are found to be located in their genomic islands. These genomic islands are novel types. This indicates that various integrons containing drug resistance genes are spreading among V. cholerae non-O1/non-O139 strains through the action of newly generated genomic islands.

Role of M.tuberculosis protein Rv2005c in the aminoglycosides resistance

Tuberculosis is an airborne infectious disease caused by Mycobacterium tuberculosis which threatens the globe. Aminoglycosides {Amikacin (AK) & Kanamycin (KM)} are WHO recommended second-line anti-TB drugs used against the treatment of drug-resistant tuberculosis. Aminoglycosides target the steps of protein translation machinery of M.tuberculosis. Several mechanisms have been put forward to elucidate the phenomena of aminoglycosides resistance but our knowledge is still insufficient. The aim of the study was to understand the involvement of Mycobacterium tuberculosis universal stress protein (Rv2005c) in aminoglycosides resistance and virulence. To establish the relationship of universal stress protein Rv2005c with AK & KM resistance, Rv2005c was cloned, expressed in E.coli BL21 using pQE2 expression vector and antimicrobial drug susceptibility testing (DST) was carried out. STRING-10 was also used to predict the interacting protein partners of Rv2005c. DST showed that the minimum inhibitory concentration of induced recombinant cells (Rv2005c) were five and four folds shifted with AK and KM E-strips, respectively. STRING-10 showed the interacting protein partners of Rv2005c. Overexpression of Rv2005c leads to shifting in MIC which might be signifying its involvement in the survival/resistance of Mycobacteria by inhibiting/modulating the effects of AK and KM released from the E-strips. Interactome also suggests that Rv2005c and its interacting protein partners are cumulatively involved in M.tuberculosis resistance, stresses, and latency.

FREQUENCY OF STAPHYLOCOCCUS AUREUS IN BLOOD STREAM INFECTIONS AND THEIR DRUG SUSCEPTIBILITY PATTERN

Background: Staphylococcus aureus is important cause of blood stream infections. The objectives of this study were to determine the frequency of Staphylococcus aureus in blood stream infections and their antimicrobial drug susceptibility pattern. Materials & Methods: This cross-sectional study was conducted at the Department of Pathology, Shaikh Zayed Hospital, Lahore from April 2018 to March 2019. The sample size was 1527 positive blood cultures for bacteria selected through consecutive sampling technique. Research variables were; presence of positive blood cultures, presence of staphylococci in positive blood cultures, types of staphylococci and types of staphylococcus aereus. Frequency and percentage of blood stream infection caused by Staphylococcus aureus and susceptibility of Staphylococcus aureus to various antimicrobial drugs was detected by disc diffusion and e-strip method. Results: Out of 12744 blood cultures, 1527(11.98%) were positive for bacteria. Out of these 1527, 339(22.20%) were positive for staphylococci. Out of these 339, 87 (5.69%) were staphylococcus aureus. Out of these 87, 48 (3.14%) were methicillin resistant (MRSA). Susceptibility of S. aureus isolates to various commonly used drugs was also detected. Conclusion: Staphylococcus aureus is a significant cause of blood stream infection and can exhibit multi-drug resistance. Therefore drug susceptibility profile of pathogens prevalent in hospital should be monitored and kept in mind when prescribing antimicrobial drugs before getting results of antimicrobial drug susceptibility tests.

M. tuberculosis ferritin (Rv3841): Potential involvement in Amikacin (AK) & Kanamycin (KM) resistance

Tuberculosis is an infectious disease, caused by one of the most successful human pathogen, Mycobacterium tuberculosis. Aminoglycosides, Amikacin (AK) & Kanamycin (KM) are commonly used to treat drug resistant tuberculosis. They target the protein synthesis machinery by interacting with several steps of translation. Several explanations have been proposed to explain the mechanism of aminoglycoside resistance but still our information is inadequate. Iron storing/interacting proteins were found to be overexpressed in aminoglycosides resistant isolates. Iron assimilation and utilization in M. tuberculosis plays a crucial role in growth, virulence and latency. To establish the relationship of ferritin with AK & KM resistance ferritin (Rv3841/bfrB) was cloned, expressed and antimicrobial drug susceptibility testing (DST) was carried out. Rv3841/bfrB gene was cloned and expressed in E. coli BL21 using pQE2 expression vector. Etest results for DST against AK & KM showed that the minimum inhibitory concentration (MIC) of ferritin recombinant cells was changed. Recombinants showed two fold changes in MIC with AK and three fold with KM E-strips. Overexpression of ferritin reflect the MIC shift which might be playing a critical role in the survival of mycobacteria by inhibiting/modulating the effects of AK & KM. String analysis also suggests that ferritin interacted with few proteins which are directly and indirectly involved in M. tuberculosis growth, Iron assimilation, virulence, resistance, stresses and latency.

Cloning, Expression and Correlation of Rv0148 to Amikacin & Kanamycin Resistance

Mycobacterium tuberculosis causes tuberculosis, one of the leading causes of fatal infectious diseases worldwide. Aminoglycosides, Amikacin (AK) & Kanamycin (KM) are commonly used in tuberculosis treatment and are drugs of choice especially for category II patients. They inhibit protein synthesis in susceptible bacteria by interacting with several steps of translation. Several explanations have been put forward to explain the mechanism of aminoglycoside resistance but still our knowledge is fragmentary. Rv0148 was found to be overexpressed in AK & KM resistant isolates. To establish the relationship of Rv0148 with AK & KM resistance it was cloned, expressed and antimicrobial drug susceptibility testing (DST) was carried out. Gene was cloned and expressed in E.coli BL21 using pQE2 expression vector. Etest results for drug susceptibility testing against AK & KM showed that the MIC of recombinant cells with Rv0148 was altered. Recombinants showed three fold changes in MIC with AK and two fold with KM E-strips. These MIC shifts speculate, overexpression of Rv0148 protein might be playing a pivotal role in the survival of mycobacteria by inhibiting/modulating the effects of AK & KM. Keywords: Amikacin, Cloning & Expression, Etest, Kanamycin, Rv0148.

Antimicrobial drug-resistant bacteria isolated from Syrian war-injured patients, August 2011-March 2013.

Antimicrobial drug-resistant bacteria isolated from Syrian war-injured patients, August 2011-March 2013.

Staphylococcus delphiniand Methicillin-ResistantS. pseudintermediusin Horses, Canada

<i>Staphylococcus delphini</i>and Methicillin-Resistant<i>S. pseudintermedius</i>in Horses, Canada

Comparison of 16S rRNA gene PCR and blood culture for diagnosis of neonatal sepsis

Septicemia is a common cause of morbidity and mortality among newborns in the developing world. However, accurate clinical diagnosis of neonatal sepsis is often difficult because symptoms and signs are often nonspecific. Blood culture has been the gold standard for confirmation of the diagnosis. However, the sensitivity is low and results are usually not promptly obtained. Therefore, the diagnosis of sepsis is often based on clinical signs in association with laboratory tests such as platelets count, immature/total neutrophils ratio (I/T), and a rise in C-reactive protein (CRP). Polymerase chain reaction (PCR) methods for the detection of neonatal sepsis represent new diagnostic tools for the early identification of pathogens. During a 4-month prospective study, 16S rRNA PCR was compared with conventional blood culture for the diagnosis of neonatal bacterial sepsis. In addition, the relationship between known risk factors, clinical signs, laboratory parameters, and the diagnosis of sepsis was considered. Sepsis was suspected in 706 infants from the intensive neonatal care unit. They all were included in the study. The number of positive cultures and positive PCR results were 95 (13.5%) and 123 (17.4%), respectively. Compared with blood culture, the diagnosis of bacterial sepsis by PCR revealed a 100.0% sensitivity, 95.4% specificity, 77.2% positive predictive value, and 100.0% negative predictive value. In this study, Apgar scores at 5 min, weight, icterus, irritability, feeding difficulties, gestational age (GA), premature rupture of membrane (PRM), platelets count, I/T, and a marked rise in CRP were important in establishing the diagnosis of sepsis in the newborn. In addition, weight, GA, PRM, irritability, duration of antibiotic usage, mortality rate, and number of purulent meningitis cases were significantly different between early-onset sepsis and late-onset sepsis. 16S rRNA PCR increased the sensitivity in detecting bacterial DNA in newborns with signs of sepsis, allowed a rapid detection of the pathogens, and led to shorter antibiotic courses. However, uncertainty about the bacterial cause of sepsis was not reduced by this method. 16S rRNA PCR needs to be further developed and improved. Blood culture is currently irreplaceable, since pure isolates are essential for antimicrobial drug susceptibility testing.

Multidrug-ResistantEscherichia coliBacteremia

Multidrug-Resistant<i>Escherichia coli</i>Bacteremia

Clostridium difficileInfection Associated with Pig Farms

<i>Clostridium difficile</i>Infection Associated with Pig Farms

Prevalence of Salmonella spp. in Cane Toads (Bufo marinus) from Grenada, West Indies, and their Antimicrobial Susceptibility

Cloacal swabs and caecal contents sampled from 58 cane toads (Bufo marinus) in St George's parish, Grenada, during a 7-month period in 2011 were examined by an enrichment and selective culture method for presence of Salmonella spp. Twenty-four (41%) toads were positive for Salmonella spp. of which eight were Salmonella enterica serovar Javiana, and eight were S. enterica serovar Rubislaw. The other serovars were as follows: Montevideo, 6; Arechavaleta, 1; and serovar: IV:43:-:-, 1. The high frequency of isolation of serovar Javiana, an emerging human pathogen associated with several outbreaks in the recent years in the eastern United States, suggests a possible role for cane toads in transmission of this serovar. Although S. Rubislaw has been isolated from lizards, bats and cases of some human infections, there is no report of its carriage by cane toads, and in such high frequency. The rate of carriage of S. Montevideo, a cause for human foodborne outbreaks around the world was also over 10% in the 58 toads sampled in this study. The antimicrobial drug susceptibility tests against amoxicillin-clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, imipenem, nalidixic acid, streptomycin, tetracycline and trimethoprim-sulfamethoxazole showed that drug resistance is minimal and is of little concern. Antimicrobial resistance was limited to ampicillin and amoxicillin-clavulanic acid in one isolate of S. Javiana and one isolate of S. Rubislaw. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars not identified previously in cane toads in Grenada, West Indies.