Blood stream infection (BSIs) is dangerous condition that requires prompt medical attention. Among the most common infections associated with healthcare, BSIs dramatically raise the rate of disease and mortality worldwide.[1] Several bacteria, including the most frequent causes of bloodstream infections, Staphylococcus, Coagulase-negative Staphylococcus and Enterobacter can cause septicaemia.[2] Staphylococci constitute important pathogenic bacteria that cause a wide range of illnesses in humans. This category of organism is still classified using diagnostic techniques that need to differentiate Staphylococcus from less or non-pathogenic bacteria.[3] Species such as Staphylococcus epidermidis, Staphylococcus hemolyticus, Staphylococcus lugdunensis, Staphylococcus Schleifer, Staphylococcus warneri, Staphylococcus hominis, Staphylococcus simulans, Staphylococcus capitis, Staphylococcus congii, Staphylococcus xylosusand Staphylococcus saccharolyticus are usually involved.[4]

Coagulase-negative Staphylococci are considered to be highly pathogenic as significant nosocomial infection agents.[5] Some new drugs that can kill CoNS well have been used in clinics like linezolid, tigecycline and daptomycin. Resistance to linezolid in cons been observed when linezolid treatment for bacteremia caused by S. epidermidis failed in a patient with acute myeloid leukaemia.[6] S. haemolyticus has demanded increased interest due to the emergence of glycopeptide resistance in this species. Thus, finding CoNS and their resistance to antibiotics should be taken very seriously in treatment because by being resistant to multiple antibiotics, their prevalence just not limits the healing action but serves like a drug-resistant gene’s reservoir.[7] In past years, there is information regarding an increment in recognition of CoNS as agents of hospital and community-acquired infections. It is difficult to differentiate contamination from infections previously disseminated as contaminations these pathogens have established their role in many infections.[8]

Study design and Ethical approval:

A cross-sectional study was conducted at TMU Hospital in Moradabad, India, with ethical approval (IEC Ref no: TMU/IEC/2024-25/PG/137). Written informed consent was obtained from all participants.

Procedure:

Blood culture samples were collected using aseptic techniques. Two separate samples were obtained by venipuncture from the right and left median cubital veins and inoculated into automated blood culture bottles. These samples were from patients admitted in the ICU with suspected bacteremia and sepsis. The inoculated bottles were incubated in the BacT/ALERT 3D system for five days. Gram’s stain was performed on all flagged bottles. Subsequent, subcultures were made on blood agar and MacConkey’s agar to isolate and identify the microorganisms.  Coagulase-negative staphylococci were identified using the Vitek-2 system and antimicrobial susceptibility testing was conducted to guide appropriate therapy.

Laboratory criteria: At least 2 culture bottles were collected from same patient.

Statistical Analysis:

Tables and figures were created using Microsoft Word and Excel.

117 adult patients were selected whose blood culture tested positive from coagulase negative staphylococci. Only 19 (16.23%) CoNS were isolated from both the hands and 98 (83.76%) were contamination. Out of total 19 BSI patients, female 12 (63.15 %) followed by male’s accounts for 7 (36.8%).

                                                     Table-1: Age Wise Distribution of CoNS

CoNS belonged to 19 to 20 age group 6 (31.58%) 30 to 39 age group 2 (10.52%) followed by 40 to 49 age group 4 (21.05%) followed by 50 to 59 age group 3 (15.79%) followed by 60 above 4 (21.05%).

                                                                    Table-2: Species Wise Distribution of CoNS

Out of 19 CoNS Staphylococcus haemolyticus 6(31.57%), Staphylococcus hominis 5(26.31%), Staphylococcus epidermidis 2(10.25%), Staphylococcus warneri 2(10.52%) and others as shown in table -2

Table-3: Antibiotics Susceptibility Pattern of CoNS

The most sensitive drugs were Vancomycin and Teicoplanin, each with 18 out of 19 isolates (94.73%) followed by Linezolid with 17 (89.47%), Doxycycline with 16 (84.21%) and Gentamicin with 15 (78.94%) and other shown in table-3.

A confirmed diagnosis and assistance in selecting the appropriate antibiotic treatment can be obtained from a culture of blood that was positive. On the other hand, because of insufficient sample collection methods and rise in usage of intravascular devices, many colonizers alike coagulase negative staphylococcus and diphtheroid may typically develop within the specimen.[9] Among the 19 patients, the age group between 19–29 years had the highest number of cases with 6 patients (31.58%) followed by the 40–49 years age group with 4 patients (21.05%). Patients above 60 years accounted for 4 cases (21.05%), the 50–59 age groups had 3 cases (15.79%) and the least affected was the 30–39 years age group with 2 cases (10.52%). (Table-1)

 A similar work conducted by Singh NH and Singh RM et al. [10] reported a high range of CoNS in the 20–29 years age group (28.88%). However, another study by Bhosle PS and Thakar VH et al. [11] revealed only 1 case (4.34%) in the same age group (20–29 years). The higher prevalence could be attributed to factors such as the use of medical devices, poor hygiene and weakened immune systems. In our study, the most common CoNS species was Staphylococcus haemolyticus6 (31.57%) was the most frequent followed by Staphylococcus hominis 5 (26.31%) and least by Staphylococcus simulans 1 (5.26%), Staphylococcus xylosus 1 (5.26%), Staphylococcus capitis 1 (5.26%) and Staphylococcus scuiri 1 (5.26%).  A study done by Bhosle PS, Thakar VH et al. [11] and their study findings that S. haemolyticus having high prevalent with 7 (30.4%). Another study conducted by Singh NH, Sing RM et al. [12] which is lowest than compare with other studies done by Bhosle PS, Thakar VH et al., Singh NH, Sing RM et al., and Raina D, Chandola I et al. [11-13] (Table-2) While most studies have identified Staphylococcus haemolyticus as the second most common CoNS strain isolated from human blood cultures, our study found it to be the predominant strain. Patients who were immunocompromised had a higher risk of CoNS infection, with 7 cases (36.84%), followed by those with prolonged antibiotic use and those who had undergone surgery, accounting for 6 (31.57%) and 4 (21.05%) cases respectively. Patients with catheters and prosthetic devices were found to have a lower risk of CoNS infection as shown in (Figure 1). A study conducted by Raina D, Chandola I et al. [13] also reported that various risk factors can contribute to bloodstream infections (BSI) caused by CoNS. Among all risk factors, prolonged antibiotic intake was the most common, with 19 cases (31.66%), followed by ICU stays with 11 cases (18.33%) and post-surgical procedures with 10 cases (16.66%). In immunocompromised patients, CoNS infections were more common due to the opportunistic nature of the bacteria and the weakened immune system, especially in those with chronic illnesses, cancer, or HIV. According to the AST (Antimicrobial Susceptibility Testing) report by VITEK-2 Compact, the most sensitive drugs were Vancomycin and Teicoplanin, each with 18 out of 19 isolates (94.73%) followed by Linezolid with 17 (89.47%), Doxycycline with 16 (84.21%) and Gentamicin with 15 (78.94%). Ampicillin-Sulbactam and Chloramphenicol also showed relatively high sensitivity with 13 out of 19 isolates (68.42%) each. In contrast, Erythromycin and Azithromycin showed high resistance rates with Erythromycin being resistant in 13 out of 19 cases (68.42%) and Azithromycin in 6 out of 19 cases (31.57%). (Table-3) A study conducted by Raina D, Chandola I et al. [13] also reported similar findings with Gentamicin showing a sensitivity rate of 47 (78.3%) and Erythromycin a resistance rate of 44 (73.3%), consistent with our results. Moreover, research by Bhosle PS and Thakar VH et al. [11,12] also found a resistance rate of 13 (56.52%) for Erythromycin.

The majority of Coagulase negative staphylococcus isolates recovered from blood cultures were initially considered contaminants however, with changes in therapeutic approaches the number of truly pathogenic organisms identified has increased. Over time, commonly used antibiotics have been losing their effectiveness against CoNS species, making treatment more challenging. It is essential to understand that not all CoNS species isolated from the bloodstream are harmful. Therefore, a thorough clinical evaluation is crucial before initiating antimicrobial therapy to prevent the overuse of antibiotics, which can contribute to rising antibiotic resistance in hospital settings. Among the antibiotics tested Vancomycin and Teicoplanin have shown the highest sensitivity rates. Following proper aseptic techniques during blood collection and avoiding the unnecessary use of antibiotics without a doctor’s prescription can significantly reduce complications caused by truly pathogenic CoNS.

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